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ECE 477 Final Report Spring 2008Team 13 Touch 2 Order

Team Members:

#1: Srichand Yella Signature: ____________________ Date: 04/28/2008

#2: Anvesh Dasari Signature: ____________________ Date: 04/28/2008

#3: Varun Vallabhaneni Signature: ____________________ Date: 04/28/2008

#4: Madhu Tummala Signature: ____________________ Date: 04/28/2008

CRITERION SCORE MPY PTSTechnical content 0 1 2 3 4 5 6 7 8 9 10 3Design documentation 0 1 2 3 4 5 6 7 8 9 10 3Technical writing style 0 1 2 3 4 5 6 7 8 9 10 2Contributions 0 1 2 3 4 5 6 7 8 9 10 1Editing 0 1 2 3 4 5 6 7 8 9 10 1Comments: TOTAL

ECE 477 Final Report Spring 2008

TABLE OF CONTENTS

Abstract 1

1.0 Project Overview and Block Diagram ?

2.0 Team Success Criteria and Fulfillment ?

3.0 Constraint Analysis and Component Selection ?

4.0 Patent Liability Analysis ?

5.0 Reliability and Safety Analysis ?

6.0 Ethical and Environmental Impact Analysis ?

7.0 Packaging Design Considerations ?

8.0 Schematic Design Considerations ?

9.0 PCB Layout Design Considerations ?

10.0 Software Design Considerations ?

11.0 Version 2 Changes ?

12.0 Summary and Conclusions ?

13.0 References ?

Appendix A: Individual Contributions ?

Appendix B: Packaging ?

Appendix C: Schematic ?

Appendix D: PCB Layout Top and Bottom Copper ?

Appendix E: Parts List Spreadsheet ?

Appendix F: Software Listing ?

Appendix G: FMECA Worksheet ?

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Abstract As a part of the ECE 477 – Digital Systems Senior Design Project course our team of

Srichand Yella, Anvesh Dasari, Varun Vallabhaneni and Madhu Tummala were able to finish

design our project the ‘Touch 2 Order’, a portable touch screen based menu for restaurants which

wirelessly transmits the order and has an integrated RFID reader. We started with the concept at

the beginning of the semester and were able to complete the project at the end of the semester

facing many challenges through various phases of design. But we had overcome all those

problems with the help provided by all the course staff and material provided to us. All the

Project Specific Success Criteria are successfully demonstrated to the course staff. The design

considerations, specifications modifications, challenges for the project are detailed in this report.

1.0 Project Overview and Block DiagramThe ‘Touch 2 Order’ is a device which enables restaurant patrons to order food from the

comfort of the table. The user is provided with a touch screen menu through which he can

navigate through various options and food items to the cart. After selecting the items and the

order placed it is wirelessly transmitted once the payment is done with the RFID card or the

Cash/Credit option.

The ‘Touch 2 Order’ has an 8.7 inch touch screen which displays the restaurant menu to

the user. With a single touch the user can select the food and beverage items and add to cart. At

the cart the user can increase or decrease the quantity of food items ordered or remove them from

the cart. When finished ordering and when the submit order is selected the display shows two

options to pay the bill, using the RFID card which can be done through the integrated card reader

in the device or through cash/credit done manually.

When the transaction is done the order is wirelessly sent to the server in the kitchen

through a Zig Bee wireless transceiver where it is placed in the order queue. The device also has

an option for customizable menu which can be done through the RFID card. The device is

entirely portable and can run with rechargeable batteries when not plugged to external power

supply.

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Figure 1.1 Overall Block Diagram for the ‘Touch 2 Order’

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24V @ 500mA Walwart input

Battery Charger Circuit

Battery Pack 12V Output

Linear Regulator 5V and 3.3V

Output

Battery Monitor Circuit 5.0V 3.3V

2 I2C3 GPIO

Freescale Microcontroller (MC9S12E128)

3.3VZigBee Wireless

Interface(XBee Pro)

2 SCI4 GPIO

RFID Reader (Sparkfun ID-12)

1 SCI

5.0V

Graphic Controller (Reach Technologies)

2 SCI

3.3V

LCD Screen (NEC 8.4”)

4

3.3V Touch Screen Panel

2


Figure 1.2 The ‘Touch 2 Order’

2.0 Team Success Criteria and Fulfillment

PSSC#1 - An ability to display information (menus, items ordered, etc.) on an LCD.

The ‘Touch 2 Order’ successfully displays all the menus and when the food or beverage

items are selected, it displays the items ordered and the total cost when the display cart option is

selected.

PSSC#2 - An ability to enter choices and select functions via touch screen entry.

User can select food items and navigate through various menus successfully with a single

touch.

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PSSC#3 - An ability to read an RFID card and use decoded user ID to look up personal

account information.

The integrated RFID reader detects the RFID tags and loads the ID into the microcontroller

which can be later used to retrieve personal information such as customized menus.

PSSC#4 - An ability to transmit menu choices over a wireless interface (e.g.,

802.15.4)

Once the order is placed it is wirelessly transmitted through the Zig Bee wireless interface

and the order is shown up on the server on the kitchen which is received through the receiver

module connected through the USB port.

PSSC#5 - An ability to charge the batteries using a charger circuit.

The ‘Touch 2 Order’ once connected to external power supply stops taking power from the

batteries and instead charges the batteries while taking power through the 12 V adapter.

3.0 Constraint Analysis and Component Selection

3.1.0 Design Constraint Analysis

The major design constraints that will be considered in this report are cost, durability and

functionality. Since the finished product is going to be mounted on a restaurant table and since

the restaurant has a lot of tables the product needs to be inexpensive. The durability factor comes

in because the product will be used on a daily basis by a lot of customers and needs to be robust.

It needs to be functional and include some convenience functions in order for the restaurants to

use them.

3.2.0 Computation Requirements

The touch 2 order system is not computational intensive, rather it is mostly interrupt driven.

Since it uses a user interface, a touch screen, a critical function would be to update the touch

screen graphics quickly in response to the user input. Another requirement would be to update

the menu according to individual preferences if a card is read from the user. The microcontroller

will only get this information when interrupted by the RFID reader. After the individual data is

retrieved from the server, the screen is updated. When the user makes the selection, the order is

sent to the ZigBee transmitter through a SCI interface.

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Since the graphic controller contains a built in SD card reader, all the images that are needed for

the touch screen can be stored in the SD card reader. In order to change the menus automatically

for breakfast, lunch and dinner, we will need to implement a timer module in the microcontroller

with an estimated clock speed 8 MHz and 128K memory.

3.3.0 Interface Requirements

There are no peripherals in the touch 2 order system that interface to the microcontroller

through general-purpose I/O pins. All the peripherals are interfaced to the microcontroller

through either SCI or SPI modules. The baud rate is about 9,600. An LED will be connected to

the GPIO.

3.4.0 On-Chip Peripheral Requirements

The touch 2 order system has three important components that are interfaced to the

microcontroller. LCD and Touch panel are connected to the graphical controller. Graphical

controller is connected to the microcontroller using SCI and TIM channel. TIM channel is used

to update the menu according to the time. The RFID reader which is connected to the

microcontroller through SCI is used for detection of RFID tags. The RFID reader has an in-built

antenna. It identifies the transponder and sends the 64 bit transponder id to the microcontroller.

ZigBee transceiver is connected to the microcontroller using SCI interface. The transceiver

communicates with UART. One TIM channel of the microcontroller is used to implement

accurate system clock. The following table gives a brief overview of the on chip peripheral

requirements.

Component Interface Part number (Make)

LCD and Touch Panel SCI (1)

TIM (1)

42-0105-01(Reach

Technologies)

RFID Card Reader SCI (1) RFID Reader ID-12(Spark

Fun Electronics)

ZigBee Transceiver SCI (1) XBee Pro RF module (Digi)

System Clock TIM (1) Using microcontroller TIM

port

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Table 3.4.1 On-Chip Peripheral Requirements

3.5.0 Off-Chip Peripheral Requirements

The Touch 2 order system has no off-chip peripherals.

3.6.0 Power Constraints

The ‘Touch 2 Order’ is an A.C powered device. There wasn’t any need for a battery as it is

fixed on the table top. Since there is no battery back up the device needs to be continuously

connected to power source. There may be little heat dissipation as it does not involve any heavy

machinery or high speed processors. The maximum power consuming component is the

backlight inverter. It consumes about 240 mA at 12 V threshold voltage. The ZigBee wireless

transceiver also consumes larger currents up to 210 mA at 3.4 threshold voltage. To reduce this

voltage strain the backlight will shut off automatically by a timer. The wireless and RFID

modules will also be working only when the necessity arrives, thereby reducing the power

consumption of the overall device. So it may require a voltage regulator of 12 V which is the

maximum required for the design. The threshold voltages and maximum currents consumed for

the major components of the ‘Touch 2 Order’ are listed in the table 2.5.1 below.

Component Voltage Threshold (V) Maximum Current (mA)

Touch screen LCD 3.3 92

LCD graphic controller 3.3 60

Backlight Inverter 12 240

RFID card reader 5.4 30

ZigBee Wireless Transceiver 3.4 215

Microcontroller 3.3 65

Table 3.6.1 Power Requirements of Major Components

3.7.0 Packaging Constraints

The ‘Touch 2 order’ is intended especially for use in fast food restaurants where the food

service needs to be quick. These types of fast food restaurants are usually crowded. So our

device should be able to withstand heavy daily usage. The device must also be packaged so that

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it should be protected from any food and drink spills. Our total packaging would consist of LCD

touch screen panel, LCD graphical controller, Backlight inverter, RFID reader, wireless

transceiver, microcontroller, PCB and any other circuitry required. The packaging should be

made so that there are enough gaps between the components and the overall product should also

be compact. The RFID reader should be placed so that it would easily detect the RFID tags.

Similar is the case with the wireless transceiver, it should be placed so that its signals are

properly transmitted to the kitchen server. Since the range of the wireless transmitter is good

enough, there would not be any shielding effects due to the packaging. Since the device is always

connected to power and is fixed at some place it is not required that it should be portable and

light. But as the device runs directly with DC voltage and has no major heavy components it

should be light enough to be transported if required. So the main constraint would be the outer

packaging to make it withstand heavy and harsh usage rather making it lighter and portable. The

package we chose was a perfect fit for the design and spacious enough to fit in all the

components of our design.

3.8.0 Cost Constraints

At present there are no such devices in market which allow the user to order and pay. Some

fast food restaurants such as McDonalds do have such a kind of devices but they do not allow the

user to select his choice, whereas the ‘Touch 2 Order’ is unique in its kind which also wirelessly

transmits the order to the server in the kitchen thereby making it quicker. The estimated cost of

the device would be approximately $800 which is quite high. But this is a one time investment.

Once implemented it would be cost effective for the restaurant owner as it reduces the manual

work so the cost of the device can be recovered in no time. Also if the product is manufactured in

bulk, it would also reduce the price of the device there by making it more cost effective.

3.9.0 Component Selection Rationale

The touch 2 order system that is being made consists of mainly a touch screen kit,

microcontroller, RFID reader and a ZigBee transceiver. The above devices are discussed in detail

in the following sections:

RFID Reader:

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RFID reader is used to detect the Transponder. Transponders are used to pay the bill.

Short range RFID reader is sufficient as the reader should not detect the other readers present at

the other tables. Following table gives specifications for two short range RFID readers. Cost,

Power and range are the important constraints in selecting the correct part required for the

project. Spark Fun Electronics reader is very cost effective and consumes low power.

Table 3.9.1 RFID Comparison

ZigBee Wireless Transceiver:

Wireless Transceiver is used to send the data from the ‘Touch 2 order’ system to the

kitchenette. To implement this ZigBee technology is selected as it is a standard technology. The

technology meets 802.15.4 standards. Wide varieties of ZigBee modules are available. The table

compares wide variety of ZigBee modules and there specifications.

In selecting the ZigBee module range is given more importance. So, XBee Pro is selected as the

ZigBee Transceiver [10].

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Manufacturer Texas Instruments Spark Fun Electronics

Part number RI-STU-MRD1 ID-12

Voltage Supply 5VDC 5VDC

Current 100mA 30mA

Interface SCI (1) SCI (1)

Integrated Antenna Not present Present

Frequency 134.2 kHz 125 kHz

Cost $91 $29.95

Manufacturer Atmel Maxstream

Part Number ATmega64RZAPV XBee Pro

Interface SPI (1) and 4 I/Os SCI (1)

Supply voltage 3.6VDC 3.3VDC

Current 16.5mA 215mA

Cost $12 $32

Range 120mts 1000mts

Power 10dBm 20dBm


Table 3.9.2 ZigBee Transceiver Comparison

Touch Screen:

Choosing the touch screen was an important task. We needed a large screen size to

display the graphics so that the user will be able to read the text and operate with bare hand.

Since it would be convenient to buy a touch screen kit with LCD, touch overlay and a graphics

controller, we compared two touch screen kits, one from Reach and one from Apollo [5] , [6].

The LCD’s were of the same size and the graphics controllers came with very good

documentation. The Reach module supports SD card for external memory [5]. Finally the Reach

module was chosen because it has been used in the previous semesters and it is well documented

[5].

Make Reach Technologies Apollo Display Technologies

Model 42-0105-01 T-51638D084J-FW-A-AB-V399B

Touch-Screen Yes Yes

Display Size 8.4” 8.4”

Backlight Yes Yes

Memory Type External SD On board flash

Interface RS232 RS232

Price $699.00 $649.00

Table 3.9.3 Touch Screen Comparison

Microcontroller:

The main constraints that were considered in choosing the microcontroller are the number

of SCI and SPI modules and the amount of flash memory on the microcontroller. The touch 2

order system needs 3 SCI modules one each for ZigBee transceiver, RFID reader and graphics

controller. It also needs a TIM module to maintain the system clock. Since we are going to

configure the menu system, we needed a large flash memory (128 kB). Three microcontrollers

were compared one from Freescale, one from Atmel and one from PIC. PIC microcontroller has

been ruled out because of the 2 SCI modules but the system needed 3 SCI modules [8], [7]. In

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comparing the Atmel microcontroller and the Freescale one, Atmel one is more expensive and

has less RAM on board [8],[7]. And also the Freescale one has more clock speed and the

development group has experience with the Freescale microcontrollers [7].

Make Freescale Atmel PIC

Model MC9S12E128 ATMega1280 dsPIC33FJ128MC706

Bits 16 8 16

Clock speed 25 MHz 16 MHz 40 MHz

Pins 80 86 64

SCI 3 4 2

SPI 1 2 2

Flash memory 128 kB 128 kB 128 kB

RAM 16 kB 8 kB 16 kB

Development Tools Code Warrior AVR Studio MP Lab

Price $14.00 $15.76 $6.77

Table 3.9.4 Microcontroller Comparison

4.0 Patent Liability Analysis

4.1.0 Introduction

The patent liability issues would be regarding the usage and features of these components

but as far as the interfacing or licensing is concerned it is automatically covered with the

purchase of the product.

4.2.0 Results of Patent and Product Search

Three patents have been found that have similar functionality as the T2O system. These patents

have been found based on the functions of the T2O system like the touch screen display, radio

frequency link, RFID card reader and the method of display of the menu. The following are the

patents that are found:

2.1 Portable point of sale terminal (US Patent #: 5408077) [1];

2.2 Apparatus for order entry in a restaurant (US Patent #: 5003472) [2]; and

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2.3 Customer self-ordering system using information displayed on a screen

(US Patent #: 5235509) [3].

4.2.1 Portable point of sale terminal (US Patent #: 5408077)

Filing Date: 04/25/1994

Abstract: Data can be input to the terminal via a keyboard assembly, a touch-screen display or a

signature-capture screen assembly, or via an antenna and radio link from an associated bar code

scanner. Data may be communicated at any time to a remote host computer via a radio link. The

communication links with the host computer and the bar code scanner operate independently and

simultaneously [1].

Relevant Claims:

a) A hand-carryable housing having a front face

b) A display mounted on the front-face of the housing

c) A power source located within the housing

4.3.0 Apparatus for order entry in a restaurant (US Patent #: 5003472)


Abstract: Apparatus for order entry in a restaurant consists of a host computer and remote

portable terminals. Orders are sent from the remote terminals to the host system through a radio

frequency communication. The terminals include a bar code template of menu items and a light

pen for scanning menu items. Printers are used at the host system to print receipts for the cooks

in the kitchen [2].

Relevant Claims:

a) A portable terminal consisting of a display

b) Wireless communication for sending data to host

c) Display means at host for conveying information to the cooks

4.4.0 Customer self-ordering system using information displayed on a screen

(US Patent #: 5235509)


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Abstract: This apparatus facilitates a self-ordering system for a fast food environment. This

apparatus includes a terminal having a touch screen for self-ordering operation. Food items are

arranged according to food categories. Primary display contains indicia representing categories

for food items. By touching the screen, the user can navigate and select the food items of choice.

Some indicia also initiate some predetermined functions such as cancellation of a previously

selected items or an indication that order has been completed. One of the screens requests as to

whether the customer wants to take out the ordered foot items [3].

Relevant Claims:

a) Customer terminal includes a touch screen wherein solid food items are selected by the

customer by touching indicia associated with selected solid food items on touch screen

b) Food indicia representing a plurality of solid food items

c) A cashier terminal having a display with functions like cashing out an order, entering

discount information and changing an order

4.5.0 Analysis of Patent Liability


The Portable Point of Sale is similar to the ‘Touch 2 Order’ in few ways. One of them is that

in Claim #1 in the patent it mentions it is a hand-carryable housing having a front face which is a

common point in our ‘Touch 2 Order’ [1]. It also has display and a keyboard on the front face.

Although our device consists of a display on the front face our project doesn’t consist of a

keyboard as it is completely operated by the touch screen interface. In Claim #2 it mentions

about the card reader the front face has a slot to accept one edge of the card [1]. The ‘T2O’ also

has a card reader but since it is a RFID based it doesn’t require a slot for swiping the card in.

Instead it just requires the card to be scanned over within its range to get detected by the card

reader. So it can be said that our device has some important similarities with the Portable Point

of Sale device.


The main purpose of this device is to enable the servers in the restaurant to enter the food

orders whereas the ‘T2O’ is for the customers of the restaurant. In its Claim #1 in the patent it

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mentions about consisting a display which our ‘T2O’ also does [2]. Also mentioned is a wireless

communication means for sending data communications to said host means which is also

incorporated by our device [2]. But the difference here is the type of wireless interface we are

using. The Zig Bee Wireless technology is entirely different from the radio link technology that

is incorporated in this device. The final similarity is the display at the host for conveying

information to the cooks. The ‘T2O’ also implements this feature. The order sent wirelessly from

the device is shown in the host server kitchen which is a PC in our case. So similarities with this

device are more but they are different in their own way.


(US Patent #: 5235509)

This product is almost similar to our device in terms of purpose and working. In its patent it

mentions about touch screen interface presented to the user where food items can be selected and

the order can be placed [3]. This feature has been incorporated in the ‘T2O’. The patent also

shows that the device has food indicia representing plurality of solid food items and a cashier

terminal having a display with functions like cashing out an order etc. [3]. But the “T2O’ instead

is a device which favors the customer more than the cashier. At the cashier terminal i.e. the host

server can retrieve information of the RFID card being used. Although it has some share of

similarities the ‘T2O’ is advanced in its own way with features such as wireless transmission of

orders and a battery charger for the portability.

4.6.0 Action Recommended


As far as the patent liability issues with this product are concerned there will be chances of

potential for infringement as the ‘T2O’ is a product with similar functions. The purpose it is

made and the features it includes are somewhat similar to the Portable point of sale terminal. The

patent has claims such as featuring display on the front cover and internal power system.

Although the display of this device is a touch screen it can be used only for minor functions such

as taking signatures. But the display of the ‘T2O’ is used for displaying menus to the user and

taking the inputs back from the user and the power system though internal has been designed

differently thereby avoiding any kind of infringement from this patent. But since the design is

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similar although the purpose is different, to avoid any causes of infringement the owner of the

patent should be contacted for licensing of the claim.


Similar is the case here. Wireless communication between the server and base may be a

similar feature and may arouse some doubts of potential infringement but the wireless

technology differentiates it. The apparatus for order entry in a restaurant uses radio link for

wireless transmission. The ‘T2O’ uses a ZigBee Wireless technology which clarifies that there

won’t be any patent liability issues regarding the implementation of wireless communication

between the device and the host. Another claim which may be a potential for infringement is

display at the host for conveying information for the cooks. This is a similar feature we are using

for the ‘T2O’, so since there is no possibility to add more features to change this feature the

owner of the patent should be contacted for licensing this feature or wait until the patent expires

as it was made in 1989.


(US Patent #: 5235509)

As mentioned in section 3.3 above there are three points in the claims of this patent

which may cause any potential for infringement. The cashier terminal feature may not cause

much a problem as our host is not a cashier terminal. The bill is paid at the device itself using

the RFID reader. The host is merely a display of the food items ordered and displays the

information of the RFID card used. But the first two points in the claims, customer terminal

displaying food items and food indicia representing the plurality of the items displayed on a

touch screen are the main issues. So to avoid any patent liability issues the patent owner should

be contacted and licensing should be done. We cannot afford to make any changes as they are the

core features of our device. The other way is to launch our product after a year when the above

patent actually expires.

5.0 Reliability and Safety Analysis

The main functional blocks of the device include the power supply, microcontroller and

battery circuit. The issues with microcontroller may arise during the software stages. The blocks

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which may give rise to safety and reliability issues once the product is finished are the power

supply and battery circuit. The failure in power supply may cause damage to the components of

the device which are less critical but some failures in the battery circuit may be highly critical

causing damage to the user.

5.1.0 Reliability Analysis

We chose three components, one each from the three main functional blocks of our design,

the microcontroller, MAX 1651 from power supply block and MAX 1660 from battery circuit

block. All these components are considered as MOS devices according to the military handbook

[1]. So assumptions were made accordingly while calculating the number of failures / 106 hours

and the mean time to failure MTTF.

According to the military handbook the number of failures for 106 hours for the

microcontroller can be calculated using the formula [1]. From the data

sheet of the microcontroller it was found out that the average junction temperature T J was 85oC

[2]. Based on this value and the corresponding results in the military handbook all the values

needed in the above formula were found. Since the component is a MOS device, the die

complexity failure rate, C1 = 0.28 and also, the number of pins was 80 and surface mounted,

package failure rate, C2 = 0.032 [1], [2]. Another assumption was the environment which was

assumed to be GB gave the environment factor = 2. From the class B-1 category the quality

factor was found out to be 2 and the learning factor was taken as 1. For microcircuits the

temperature factor = 7 at 85oC [1]. So by computing all the values in the equation the p was

4.048 Failures / 106 hours and the mean time to failure MTTF was 676.7 years.

Component C1 C2 p

(Failures/106

hours)

MTTF

(years)

Microcontroller 0.28 0.032 2 2 1 7 4.048 676.7

Table 5.1.0 Calculation of p and MTTF for Microcontroller

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Similarly the formula used for the microcontroller can also be used for the MAX 1660

(battery monitor) and MAX 1651 (3.3 V DC-DC voltage regulator) as they can also be

considered as MOS devices [3], [4]. Since the datasheets of these components didn’t have

enough information on the average junction temperature, it was assumed as 85oC which was just

above the maximum operating temperature. Also assuming the similar factors for these two

components as the microcontroller the learning factor , quality factor , temperature factor

and environment factor were found from the military handbook as 1, 2, 0.98, and 2

respectively [1]. For MOS devices with No. of Gates ranging from 1-100, the die complexity

failure rate, C1 = 0.0025. The only value that is different for these two components is the package

failure rate C2 since they differ in the No. of pins. The No. of pins for MAX 1660 and MAX 1651

are 16, 8 respectively which give a value of C2 = 0.0056 for the former and C2 = 0.0026 for the

later [1], [3], [4]. So computing all the values and calculating the number of failures per 106

hours and MTTF gave the following results. For MAX 1660 p = 0.0273 failures / 106 hours and

MTTF = 36.6e6 and for MAX 1651 p = 0.0153 failures / 106 hours and MTTF = 65.359e6.

Component C1 C2 p

(Failures/106

hours)

MTTF

(years)

MAX 1660 0.0025 0.0056 2 2 0.98 1 0.0273 100.273e3

MAX 1651 0.0025 0.0026 2 2 0.98 1 0.0153 179.065e3

Figure 5.1.1 Calculation of p and MTTF

By observing the above calculated values for the three components it is known that the rate

of failure is very less. So there may not be any major changes in the design or analysis

refinements that may realistically improve the reliability of the design. Since the major cause is

the operating temperature which may gradually increase the rate of failure modifications can be

made to control the temperature of these components so that it wouldn’t reach the junction

temperature. One of those considerations may be implementing fan to allow heat dissipation of

the devices.

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5.2.0 Failure Mode, Effects, and Criticality Analysis (FMECA)

The ‘Touch 2 Order’ device has 3 main functional blocks. They are the power supply circuit,

microcontroller and the battery charger and monitor circuit. Each block has its share of failure

modes, effects and criticality levels. The criticality levels for our design are high if there is any

injury involved to the user with a rate of p 10-9 and low if it involves any damage to

components, inconvenience to the user and any signal loss with a failure rate 10-9 < p < 10-3.

5.2.1 Power Supply Circuit

As shown in Appendix A the functional block of the power supply circuit consists of the DC-

DC voltage regulators MAX 1649 and MAX 1651 which give an output of 5 V and 3.3 V

respectively [3], [4]. There are four failure modes in this functional block that may occur. One of

which is that there is no output voltage which can be caused by the failure of a certain

component of the device or due to an external short. In this kind of failure mode it may lead to a

total device failure. This is a low critical failure mode as there is no injury to the user. The other

failure modes that may occur are the output voltage crossing the values of 3.3 V and 5 V. Since

the Microcontroller, XBee Pro Wireless transceiver and the LCD work with an operating voltage

of 3.3 V. A voltage increase for these components may lead to the damage of the respective

components. A possible cause may be the failure of MAX 1651 which generates the output

voltage of 3.3 V. Similarly a failure of MAX 1649 may lead to an output voltage more than 5 V

causing damage to the RFID reader. These are very less critical as only damage of components is

involved. Sometimes the output voltage may go out of tolerance when there is a failure in the

DC-DC voltage or regulators or a short in the bypass capacitors for which the effects may be

unpredictable. This is critically high as it may produce excessive heat dissipation causing

potential for injury to the user. All the above failure modes are observable from the operation of

the device.

5.2.2 Microcontroller

Another functional block shown in Appendix A is the microcontroller which involves minor

failure modes where the communication with the components connected to it would be lost. So

there are three major components connected to the microcontroller, the XBee Pro wireless

transceiver, LCD touch screen and the RFID reader. So the failure modes are connection lost

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with the host server, blank LCD screen and data not being retrieved from the RFID reader. The

possible cause for these failures may be a damage caused to the microcontroller or an error in the

software involving the respective components. So there would be no transfer from the

microcontroller to the respective components. These failures may be detected by mere

observation and are critically low.

5.2.3 Battery Circuit

The final important functional block of the ‘T2O’ is the battery charger and monitor circuit.

Three modes of failure were detected in this functional block which includes MAX 712 the chip

for battery charging circuit and MAX 1660 the chip for battery monitoring circuit. One of the

failure modes is that the charge level in the battery is not detected correctly which is caused by a

failure in MAX 1660. Another failure mode is that the batteries might not get charged caused by

a failure of MAX 712 or MAX 1660 or due to dead batteries. When this happens the device

cannot work without the external power supply. The above two failure modes are critically low.

But the final mode of failure is critically high which has a potential for causing injury to the user.

Sometimes a failure in the MAX 712 or MAX 1660 may cause overcharge in batteries leading to

leakage or explosion in the batteries which is dangerous. It not only causes damage to the user

but also to all other components of the device.

6.0 Ethical and Environmental Impact Analysis

Many ethical and environmental challenges arise while designing, manufacturing, during

usage and disposal of this kind of a device. Ethically the device should ensure security to the user

and also instructions and cautions regarding the usage should be thoroughly provided. Since the

device deals with RFID tags security should always be prime concern ethically. Environmentally

many issues arise right from manufacturing stage to the device disposal. Recycling issues with

the components such as batteries, LCD screen and the PCB should be well considered as these

components are toxic and may release chemicals if not disposed in a proper way.

6.1.0 Ethical Impact Analysis

A device such as the ‘Touch 2 Order’ requires a quite a lot of ethical issues to be considered

since the device incorporates a RFID reader and a Zig Bee wireless interface. Therefore many

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security and privacy issues are associated with it which is needed to be considered in the design.

Other ethical challenges include testing the device under different temperatures and placement of

warning labels etc. Since the ‘T2O’ incorporates rechargeable batteries providing sufficient

cautionary information regarding this should also be considered.

First and foremost security and privacy issues, with the use of RFID readers there is always a

possibility of information of the RFID card being leaked out. Since there is an option in the

‘T2O’ where the user can create his choice of customizable menu, such information should be

password protected. So the coding should be done appropriately that the user can only see his

customized menu. This information cannot be retrieved from the database. One can only access it

by using the specific RFID card. So customized menu can be only displayed at the database

when the user finishes his order thereby keeping the user choices private. Using a wireless

interface always gives scope for hacking. Since the wireless interface here is a Zig Bee which is

a rare one; eliminates a lot of security issues since the hacker also needs a Zig Bee receiver to

retrieve the order sent from the transmitter built-in the device. Also, it will be password

protected. So to access the information being received from the transmitter the host server

requires a special password keeping the information secure.

Next for the device to ensure proper working for a long span of life time, it should be tested

under various operating conditions. After the PCB is populated and whole circuit built up, the

device is tested under different operating temperatures to check its performance. So ethically it

would be important to publish all the tests performed on the device in the user manual so that the

customers buying this product would be aware of these facts and can trust the product and

purchase it.

Finally safety issues form the major part of the ethical impact analysis. Since the device uses

rechargeable batteries, it may lead to many serious damages such as leakage or explosion if not

used properly. So safety measures are a top priority in this case. Enough guidelines should be

posted on the user manual regarding the usage and time to change the old batteries. So user

should be provided with the information regarding how many charging cycles usually the

batteries can handle and after how many days is it good to change the old batteries. It is also a

good idea to provide guidelines on what to do and what not do in cases of battery leakage or

explosion.

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6.2.0 Environmental Impact Analysis

Manufacture, normal use and disposal/recycling are three different stages where issues

regarding environmental impact arise. So it is necessary that changes should be made

accordingly in the design to overcome those aspects and to environment friendly and also

providing enough information for the user regarding proper usage and disposal.

6.2.1 Manufacturing Stage

During manufacture stage the main environmental impact issue that the manufacturer of

every product should be considering is the fabrication of PCB with lead. Care should be taken

while making the PCB by using RoHS compliant materials. RoHS is often referred as lead-free

directive [2]. Substitutes such as tin and silver should be considered instead of lead which may

reduce its negative impact on the environment. Also the packaging which is a part of the

manufacturing process has its share of impact on the environment. Materials such as plastic or

aluminum should be considered. Companies such as PCBexpress.com and Trianglecircuits.com

manufacture RoHS compliant PCBs.

6.2.2 Normal Usage

The normal usage of ‘Touch 2 Order’ has the least impact on environment as it doesn’t emit

any harmful radiation or excessive heat dissipation. The only problem arises when there is a

leakage or explosion in battery. A cause for this may be a high operating temperature at which

the batteries cannot withstand and a leakage is possible. So at such times the batteries should be

immediately replaced with new batteries. Here the disposal of the leakage batteries is an

environmental issue. It is better to clean or rinse before throwing away the batteries as the

chemicals are harmful for the environment [1]. Guidelines regarding disposal of leakage batteries

are to be made available to the user. Also information for proper charging and storage of the

product should be provided in the user manual. It is always good to store the device at room

temperature to avoid damage to components and batteries.

6.2.3 Disposal / Recycling

Disposal and recycling are major concerns for every device which consists of components

that release chemicals and toxics which are not at all eco-friendly. So it should be disposed in

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such a way that it doesn’t affect the environment. The ‘T2O’ consists of an LCD screen, batteries

and components such as wireless transceiver and RFID reader which may potentially release

chemicals if not disposed properly. So it is always a good way to return the part to the

manufacturer who will be able to make good use of it by recycling or reusing it. There are some

companies which recycle almost all the electrical components such computer monitors and other

parts etc. So it is always a good choice to contact such companies at the time of recycyle. One

such company is the DMC recycling company which widely encourages recycling of electrical

components. Guidelines for disposal of such toxic components are given in EHS (Environmental

Health & Safety) website [3]. There are also some batteries recycling services such as Battery

Solutions Inc [4] which recycle wide range of batteries from rechargeable AA batteries used in

the ‘T2O’ to heavy batteries used in cars and machinery. All these instructions and guideline

must be made available to the user by giving the information in the user manual or labeling the

device.

7.0 Packaging Design Considerations

The T2O system should be tough for everyday use. The cost of packaging should be as low

as possible to keep the overall price of the product as low as possible. So the main constraints

that were considered in packaging were size, durability, portability, heat dissipation and cost. To

keep the front side of the packaged system as neat as possible, it was planned to only put the

RFID card reader on the front side in addition to the touch screen.

7.1.0 Commercial Product Packaging

The two commercial products we want to compare with our ‘Touch 2 Order’ device are

Microworks POS Solutions Inc. Tableside POS and the IBM Sure POS 700 Series [1], [2].

7.1.1 Product #1

This Wireless Tableside Ordering device is powered by Microsoft Windows XP and the

standard 802.11 wireless technology [1]. It is a very slim, sleek and a stylish device. It has a

screen size is 7 inches diagonally with an 800 by 600 pixel VGA resolution. The touch screen

can be used by a stylus touch pen. This device is manufactured keeping the servers in mind and

not for customer use. Servers can quickly enter an order right at tableside and send that

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information to the bar or the kitchen by touch-screen or stylus. All information entered on our

handheld device is processed in exactly the same way as a fixed POS station. It includes the

ability to create new orders, update existing orders and check the status of any order.

Figure 2.1.1 Microworks POS Solutions Inc. Tableside Wireless System

The packaging of the device is very trendy. It is designed to be compact, light weight and

also powerful at the same time. The outer part is a metallic enclosure. It also consists of buttons

for navigation on the right side and power on/off button on the left side of the device. It has two

LED’s on the left to indicate power on/off and for low battery.

The main positive aspect of this device is its portability. It is very light weighing about 200-

250 grams. It also contains a battery which is rechargeable. So it is not required to be connected

to voltage source all the while. Its operating system is also a huge advantage which is Windows

OS making the GUI (Graphical User Interface) user friendly. Since it uses the regular 802.11

wireless interface it can easily be connected to any wireless router in the network and there by

connected to the server where the order from this device is received at the other end.

The negative aspect of the packaging is the device is pretty delicate. So it may not be able to

withstand harsh usage and may get damaged if fallen on a hard surface. Since it is for the servers

in the restaurant it may be easy to use but if the customer is required to use he may find it

difficult using it for the first time. The LCD screen is small so the clicks from the stylus should

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be properly pin pointed, otherwise there may be wrong orders. One more constraint of this

device is it doesn’t have an RFID card reader thereby not allowing it to pay the bills from the

device. Although we could adapt some features from the packaging of this device to make the

‘Touch 2 Order’ as compact as it can get.

7.1.2 Product #2

The IBM Sure POS 700 is the industry’s premier point of sale solution for retailers who

demand adaptability and performance [2]. It empowers the restaurant owners to manage their

store environments more competitively. It is designed so that it maximizes uptime and helps

reduce maintenance costs with virtually tool-free design, secure and easy front access and

exceptional serviceability. It runs with an Intel Core 2 Duo Processor.

Its packaging quite hefty as it is very high powered and has many features. It consists of a

touch screen monitor attached to the CPU of the system and on the left side it has the card reader.

Internally packaged are the processor, 80 GB hard disk, an optical drive which reads both CD’s

and DVD’s. On the back side of the CPU are the expansion ports for PCI , secondary hard disk

drive, floppy disk drive, USB and RS-232 ports, Ethernet socket, Video and Audio outputs and a

headphone jack. It also has extra external peripheral options for printers, keyboards and cash

drawers.

Figure 2.2.1 IBM Sure POS 700 Series

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As this product is designed mainly for the benefit of the restaurant owner than the customer

it is quite heavily packed. It weighs around 13.2 Kg. Its dimensions are Narrow: 320 x 475 x

117.3 mm and Wide: 435 x 475 x 117.3 mm. It is designed so that it can withstand any harsh

usage.

The positive aspects are it is highly powered and has so many features, some necessary and

others not. This is ideal if you really need such a high performance speeds at work. Its cable arm

facilitates access to all connectors from the front of the unit. It has built in power management

and uses recycled plastics for the outer enclosure making it environmentally friendly. It has

numerous selectable and upgradable ports on the back of the system enabling the user to use the

existing devices and add new devices for meeting the ever changing business needs.

The main negative aspect of this product is its portability. It is not mobile and cannot be

transported easily. It is also very costly. A single product costs around 3000$. It does not have

wireless capability which is a main feature in our ‘Touch 2 Order’. There are no aspects in this

product which we could adapt for our device since the ‘Touch 2 Order’ is a portable and cost

effective device which also promises reasonable system performance.

7.2.0 Project Packaging Specifications

As mentioned in the above sections, the main packaging constraints that were considered

were the size, durability, portability, heat dissipation and cost. The only two human interfaces

that are there in the system are the touch screen and the RFID card reader. So the touch screen

and the RFID card reader are the only peripherals that are being put on the front side of the

system as shown in the CAD drawings in Appendix A.

The estimated size of the box for packaging the system is 226mm x 157mm x 47mm. That is

about the size of a portable DVD player with screen. The thickness of the packaged product will

be about the thickness of a regular laptop. Since this is going to be used by the customers at the

restaurant, it should be convenient for them to handle it and yet tough enough so as not to break

or crack easily.

Internally the parts are packaged in such a way that there is enough space (to reduce heat)

between the graphic controller and the PCB of the system. The graphic controller is packaged

right underneath the LCD screen and the PCD mounted with Zig Bee transceiver is placed under

the graphic controller with some space in between. The RFID card reader is mounted to the top

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of the box, so it is easy for the reader to detect any card that is placed nearby to the top of the

box.

The T2O team has decided to use a plastic enclosure for packaging the system. For the

enclosure, two materials were considered – plastic and aluminum. We chose plastic over

aluminum as there may be effects of shielding for the RFID reader and the wireless transceiver.

The system directly plugs into the wall for power.

7.3.0 PCB Footprint Layout

Several components are needed to be placed on the PCB. They are the Freescale

MC9S12E128 microcontroller, the voltage regulator and DC – DC converters, the ZigBee

wireless module and headers for graphic controller, RFID card reader and the general purpose

I/O’s [4], [5], [7], [6]. The following table shows the area each part occupies on the PCB.

Table 7.3.1: Area analysis for the PCB

From the above table and the box requirements, a size of 7” x 4” was chosen for the PCB. With

this size for the PCB, there is a lot of space for any limiting resistors or by-pass capacitors.

8.0

Schematic Design Considerations

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Part Area (in2)Freescale MC9S12E128 1.00Maxstream XBee ZigBee Transceiver 1.24Voltage Regulator and DC – DC converters 0.5

Headers 3.00Total Area: 5.74


The major components involved in the circuitry of this device are the touch screen with LCD

controller, RFID card reader, Zig Bee Wireless transceiver and the microcontroller which is

integrated to all other major components in the circuit. All these components have different

modes of operation, interface methods and power constraints. So it should be designed so that it

meets all the requirements. The circuitry for each component is individually designed and later

integrated with the other parts of the device to avoid any troubleshooting later.

8.1.0 Theory of Operation

All the major components of the device are chosen so that they can integrate efficiently with

the overall device. There were many hardware constraints for these parts the important one being

power consumption of each individual component. The voltage input for the system is 12V DC.

So each component of the device demands an individual circuitry so they are sourced with

required voltage.

8.1.1 Overall Power Supply

The voltage source for the whole device comes from a 12 V DC voltage adapter. So the only

device which is connected directly to the power source is the backlight inverter which requires a

voltage of 12 V. The remaining components have different voltage requirements. So to produce

the needed voltage values for those individual parts a DC step down voltage controller was a

necessity. The voltage regulator has the capacity to produce variable voltages from 3.3 V to 5 V

which are required by the Freescale MC9S12E128 microcontroller, Spark Fun Electronics ID-12

RFID reader, Maxstream XBee Pro wireless transceiver and the Reach Technologies LCD

graphical controller and the touch screen panel.

The microcontroller, Zig Bee wireless transceiver, Touch screen panel and the LCD

graphical controller operate at a voltage of 3.3 V but the RFID card reader requires an operating

voltage supply of 5 V [1], [2], [3], [4]. So the voltage regulator will produce an output of 3.3 V

to source voltage to all the major components except the RFID reader which needs 5V voltage

supply. Also the microcontroller has an operating frequency of 16 MHz with a 3.3 V supply and

25 MHz at 5 V supply. We chose a supply voltage of 3.3 V for the microcontroller. So a 5 V

supply voltage is provided only for the RFID reader.

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The ‘Touch 2 Order’ will not consist of any other pushbuttons or switches other than the

reset button which resets the overall device when pressed. So the overall input for the device

would be a 12 V power supply which is internally connected to the backlight inverter and the

DC-DC voltage regulator.

8.2.0 Freescale MC9S12E128 Microcontroller

Maintaining lower power consumption of the device is quite an important issue. So there

arises a need to maintain minimum operating frequencies for the microcontroller. The

microcontroller has three SCI and one SPI ports [2]. Only the three SCI ports are being used here

to connect to the RFID reader, wireless transceiver and the touch screen with LCD controller

which is interfaced through RS-232. To maintain a low clock frequency of 16 MHz a 3.3 V

voltage supply is required. This frequency is more than enough to maintain the baud rates of the

device ranging from 115,200 of the LCD display to 9,600 of the Zig Bee wireless transceiver and

the RFID reader.

8.2.1 Reach Technologies Touch Screen with LCD controller

The touch screen and the LCD graphical controller need a supply voltage of 3.3 V while the

backlight for the LCD needs a 12 V supply. The LCD graphical controller has an integrated

microprocessor which controls most of the operations of the touch screen and the backlight. It

has a maximum baud rate of 115,200 with which it will communicate with the microcontroller

through the serial interface so the display is updated at the maximum speed possible [3]. The

second LCD controller interface can be used to connect it to the PC for programming of the LCD

module with the help of a RS-232 level translator. The baud rate for this can be less than 115,200

as maximum speed is not a requirement for the programming of the LCD module.

8.2.2 Spark Fun Electronics ID-12 RFID card reader

The RFID card reader is operated at a voltage of 5V [4]. Two pins of the card reader are

connected to the microcontroller through its SCI port for the data transfer. The microcontroller

gives the instructions when to send data from the card reader. So the whole data transmission is

controlled by the microcontroller. The RFID card reader is operated at 9,600 baud rate.

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8.2.3 Maxstream XBee Pro wireless transceiver

The XBee Pro wireless transceiver is operated at 3.3V it is connected through the SCI serial

interface with the microcontroller [1]. Through its serial port it can communicate with any logic

and voltage compatible UART. Similar to the RFID reader two pins of the microcontroller are

connected to this component for data transfer. The maximum speed at which the wireless

transceiver can communicate with the microcontroller is 9,600 baud. The wireless transceiver

takes instructions from the microcontroller and wirelessly transmits the data to the receiver

module.

8.3.0 Hardware Design Narrative

The ‘Touch 2 Order’ system has 3 major building blocks namely RFID module, ZigBee

Module and Graphical controller with LCD and Touch Panel. The connections between these

modules and microcontroller can be seen in the schematic in Appendix A. The LCD and Touch

Panel are connected to the Graphical controller through the jumpers on the controller. Graphical

controller is connected to the microcontroller using SCI and a GPIO [2]. RFID module is

connected to the microcontroller using SCI. ZigBee module is connected to the microcontroller

using SCI and 4 GPIOS. So the ‘Touch 2 Order’ system requires 3 SCI ports and 5 GPIOS. SCI

of port S will be connected to the RFID reader Data pins. RFID has inbuilt antenna and tuning

capacitor. RFID works at 9,600 baud rate. SCI of port S is connected to the Data pins of XBee

Pro ZigBee transceiver. There are 4 others pins on ZigBee module which are connected to the

PAD pins. PAD7 is connected to the RESET with a 50k pull up resistor. PAD6 is connected to

the Sleep pin. This pin puts the ZigBee in sleep mode when required by the microcontroller.

PAD5 is connected to the RTS and PAD4 is connected to the CTS [2]. SCI of Port M is

connected to the graphical controller. RTS of Graphical controller is connected to the PQ [0] of

port Q. The Graphical controller works at 115,200 baud rate.

The microcontroller has a clock frequency of 25MHz at 5v. ‘Touch 2 Order’ system requires

communicating at 9,600 baud rate with both ZigBee and RFID reader. The ‘Touch 2 Order’

system requires two power supply voltages – 5 V and 3.3 V. National semiconductor’s LM 2679

DC to DC regulators are used to generate 3.3 V and 5 V from 12 V. LM 2679 is connected with

current limiting resistors, capacitors, inductors. The exact values were calculated for both the 3.3

V and 5 V outputs [6].

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9.0 PCB Layout Design Considerations

The major components for the device are the touch screen with LCD graphical controller,

RFID reader, ZigBee wireless transceiver, DC-DC voltage converter and the 16-bit Freescale

9S12CE128 microcontroller. But the components mounting on the device would be ZigBee

wireless transceiver, DC-DC voltage converter and the microcontroller. The PCB will also have

headers for serial interface, power and general purpose I/O’s. The LCD graphical controller and

the RFID reader are connected through the serial interfaced headers since they should be

available for the user. All these parts are designed on the PCB efficiently taking the physical

restrictions of the components and also the overall device into consideration.

9.1.0 PCB Layout Design Considerations – Overall

PCB Layout design involves many factors to be taken into consideration for it to be fully

operational. One of the most important factors is noise reduction in the circuit and next is the

efficient placement of the components on the PCB. The unwanted noise in the circuit can be

reduced by placing decoupling capacitors in every design which will be either a low-inductance

axial glass or of a multi-layer ceramic.

As said above next important factor is the placement of various components on the PCB.

There is a need to separate the components on the basis of whether they are digital, analog or

noisy circuits. The circuits involving the DC-DC voltage regulators for 5 V and 3.3 V and the

power input are grouped together to one corner of the PCB. The microcontroller is connected to

headers on all sides and is connected to other digital circuitry such as the XBee Pro wireless

transceiver through the headers. Another important requirement for the successful functioning of

a PCB is placing the headers or input pins on the edges of the board. This includes the headers

for serial interface of the RFID reader and touch screen with LCD graphical controller and for

the power connection. The overall PCB should also be packaged so that it is in right contact with

the components connected which are not present on the PCB.

One more important factor that should be taken into consideration while designing a PCB is

the tracing of the connections in the circuitry of the device. It is important to minimize the

lengths of the trace connections to avoid any stray inductance and any interference with the rest

of the circuitry. The width of the trace should also be considered. It should be well enough to

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handle the current flowing through it. While routing, right angle turns are not at all advisable as

it may lead to the transmission of the reflections. It is also important to separate digital and

analog trace lines. The high frequency lines should also be at a minimum distance to avoid any

unwanted noise in the circuit. The trace lines of power and ground would also be running parallel

to each other which reduce the noise to a larger extent.

9.2.0 PCB Layout Design Considerations – Microcontroller

For the proper functioning of the microcontroller in the PCB Layout the designing should be

done with extra precision. The onboard voltage regulator for the microcontroller requires

decoupling capacitors, central point grounding and low inductance connections between VSS1,

VSS2, and VSSR. As shown in Figure 3.1 the decoupling capacitors should be placed meeting

the requirements and the central point of ground should be connected to the VSSR pin.

Figure 9.2.1 Placement of the Decoupling capacitors with respect to the microcontroller

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The 9S12CE128 Microcontroller requires a external crystal circuit to control the

internal clock generator. This circuitry will be separated from the rest to avoid any unnecessary

contact with power and ground. The VSSPL, EXTAL and XTAL connection will be as short as

possible. The power and ground traces would be running parallel to each other thereby reducing

the possibility of production of any kind of noise from the power pins of the rest of the

components of the circuit. This kind of unwanted noise may also affect the oscillator and its

output. The VSSA and VDDA pins are connected to the central power for the microcontroller.

It is not safe to have traces running beneath the microcontroller or any other circuitry

involved with it such as the decoupling capacitors or the external crystal as they are very

sensitive.

9.3.0 PCB Layout Design Considerations - Power Supply

The main components for power supply that go onto the PCB include DC – DC linear

converters, external voltage input port and a power header. All these components are placed on

the top-left corner of the PCB to isolate any noise that they produce. The external voltage input

port and the power header pins are mounted to the left edge of the board for easy connectivity

from outside.

The DC – DC linear converters have an external circuit requirement on the PCB.

Sufficient room is planned for these components on the PCB.

All the power components are being planned to be placed on the top side of the PCB. The

power trace should be wide enough to carry enough current for the system. The ground trace

should be wide to reduce any interference between components. The ground trace is planned to

be as long as possible so that there is minimal interference across all the components. Both the

traces will be run parallel to each other which will reduce the interference to minimum. All the

ground traces will be grounded at a single point. The figure 4.1 below shows the DC – DC linear

converter, LM 2679, pins.

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Figure 9.3.1: LM2679 DC – DC linear converter

VIN0, CB, Current Adj., FB, VSW0, GND and Softstart are the only pins that are used in

building the circuit for DC – DC converters. Since all the pins are analog, there are no

restrictions on routing them on the PCB, but they will be provided with adequate spacing so that

there is no interference among the signals.

10.0 Software Design Considerations

10.1.0 Software Design Considerations

The main software design considerations that the team is looking at are:

a) Easily understandable user interface

b) Simple and convenient functions and

c) Sensible flow of code

Since the users will be new to using the system, the user interface should be very easily

understandable and the functionality should be simple.

10.2.0 Code Organization

To make the code organization simple, the T2O team has decided to keep the most part of the

code to be command-driven rather than interrupt-driven. The only interrupt-driven peripheral is

the touch screen. Since it is a user interface, the interrupts generated by the touch screen are at

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random intervals. The RFID talks to the microcontroller only when the user is asked to. Any

other RFID inputs are ignored by the microcontroller. The ZigBee also talks to the

microcontroller only when the microcontroller requests information from the host computer. All

other inputs are ignored by the microcontroller. This makes the code organization easier.

Appendix A shows a detailed code flowchart.

10.3.0 Memory Map

The microcontroller configuration will be set to normal single chip mode. The variables and the

stack are stored in the RAM. The main code and the interrupt vectors are stored in the flash

memory. The CodeWarrior IDE automatically maps all the static code in flash and dynamic code

in RAM. The memory on the MC9S12E128 is arranged as follows:

$0000 - $03FF Register Space (1k)

$0400 - $1FFF System Fixed Ram Space (7k)

$2000 - $3FFF User Ram (8k)

$4000 - $FFFF Fixed Flash EEPROM (128k)

The memory map for the microcontroller is shown in the figure below:

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Figure 10.3.1: MC9S12E128 User Configurable Memory Map

10.4.0 Integrated Peripherals

The T2O application makes use of three modules namely SCI, I2C and RTI modules. All the

three SCI modules are used. The modules are discussed in detail below:

SCI0: This module is used to interface the RFID reader to the microcontroller. Only the RxD0

pin is used for communicating with the RFID reader. Whenever the microcontroller needs input

from the RFID, it displays a notification on the LCD screen and waits for the RFID input. When

the RFID tag is read, the tag ID is received by the microcontroller and stored.

SCI1: This module is used to interface the ZigBee transceiver to the microcontroller. When ever

the microcontroller needs some information from the host PC, it sends a request and waits until

the information is received.

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SCI2: This module is used to interface the Graphic controller (SLCD5) to the microcontroller.

Touch screen keeps interrupting the microcontroller when ever the user touched a hotspot. But

only a set of interrupts are recognized by the microcontroller and all other interrupts are ignored.

The microcontroller sends the battery information to the LCD every one minute. It also sends

some text to be displayed on the LCD like the products in the cart, the check total and the

customized menu selections.

I2C: This module is used to interface the battery monitor to the microcontroller. The battery

monitor updates the status of the battery to the microcontroller every one minute using the RTI

interrupt.

RTI: The RTI generates two interrupts periodically. One interrupt is generated every one minute

to request the data from the fuel gauge. The second interrupt is generated at five minutes interval

after the user touches the screen. This makes sure that the system goes into sleep after a five

minute interval if the touch screen is not touched.

The implementation of these modules and the GPIO pins is listed below:

SCI0: PORTS (0) – RFID input

SCI1: PORTS (2:3) – ZigBee input output

SCI2: PORTM (4:5) – Graphic controller input output

I2C: PORTM (6:7) – Fuel Gauge input output

GPIO: PORTM (3), PORTQ (2:3) – Fuel Gauge control inputs

PORTQ (0) – Graphic controller reset pin

PORTAD (4:7) – ZigBee control inputs and outputs

10.5.0 Software Design Narrative

The Touch 2 Order system has three main interfaces with the MC9S12E128 microcontroller.

They are Touch screen, RFID reader and ZigBee transceiver. Only RTI (Real Time Interrupt)

and Touch Screen input to the microcontroller are interrupt-driven. Remaining all functions is

program driven. The main code for microcontroller starts with the initializations for SCI (SCI_

INT), I2C (I2C_INT), RTI (RTI_INT), GPIOs (GPIO_INT). Then the program enters an infinite

loop. In the loop the code waits for Touch Flag. This flag is set to one when there is touch

screen’s interrupt. This is taken care by the IN_LCD function. When user touch the touch screen

the LCD wakes up from the sleep mode and displays the welcome message and sends an

interrupt to microcontroller. This interrupt sets Touch Flag one. After Displaying welcome

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screen LCD displays two options. Those options are full menu and custom menu. All this is

taken care of by the graphical controller in the touch screen.

When user hits full menu, it displays lunch menu and breakfast menu. The corresponding menus

are displayed by the user selection. For example it displays Beverages, Main course, Sides,

Deserts. If user selects beverages it displays different beverages available. If user selects coke the

corresponding touch interrupt is send to the microcontroller. IN_LCD function receives the data

from the Touch screen Through SCI2 receive pin. After receiving data, IN_LCD calls

ADD_CART function. ADD_CART function compares the input data from SCI2 to the

predefined array menu1. If the data corresponds to an element in the array menu1, the

corresponding order number is added to the array ‘order’. When user hits ‘Done’ on the touch

screen, INT_LCD function calls the function DISP_CART. DISP_CART displays final order of

the customer using the array ‘order’. The LCD waits for the user to press ‘Check Out’ button.

When user hit that, it displays payment options. The payment options are RFID or Cash. If user

presses RFID option IN_LCD function set PAY_RFID flag to one. When PAY_RFID flag is one

it calls IN_RFID function. When RFID reader detects an RFID tag it sends the tag number to the

microcontroller using SCI0 RX pin. IN_RFID accepts this data. After this the main function calls

OUT_ZIGBEE. This function sends order array which contains customer order and RFID tag

number to the kitchenette server using SCI1 TX pin. Then the code calls IN_ZIGBEE.

IN_ZIGBEE waits for the confirmation from the kitchenette server. If it receives Y then

OUT_LCD function displays confirmation message on the LCD else it displays error message on

the LCD screen.

When user hit pay bill using cash, OUT_ZIGBEE sends order to the server. IN_ZIGBEE

function waits for the confirmation. Depending on the received data OUT_LCD displays

corresponding message.

If user selects custom menu in the starting instead on full menu, CUSTOM flag is set to one in

IN_LCD. If CUSTOM flag is set to one main code calls IN_RFID. IN_RFID receives the tag

number and sends it to kitchenette server for validity. If kitchenette server sends confirmation

A-36


main code calls OUT_LCD_COM function. This function compares the corresponding command

for the RFID number from the look up table 1 and sends the command to the LCD through SCI2

TX pin. After this it accepts order and pays bill similar to the full menu feature.

There is an RTI interrupt which is set to occur at 8.192 ms. RTI is written in the function

RTI_ISR. This function has two counters. First counter counts one minute and calls the function

BATT_CALC. This function calculates battery level using I2C interface. After this function

RTI_ISR calls BATT_DISP to display battery level. It displays both percentage and using three

bars. If battery is between 66% - 100% 3 bars are displayed on the screen. If it is in between 33%

- 66% it displays two bars or else just one bar. This function gives warning when there is 10%

battery charge left. This function also shuts the system off when battery charge is less than 5%.

The second counter in RTI_ISR is used to switch off back light of LCD, when counter reaches

5*60*122 value.

MAIN( ) – This function calls all the functions. It has an infinite loop.

- Outlined the pseudo-code.

SCI_INT( ) – This function has all the initializations for the three SCI ports. All ports are set for

9600 baud rate.

- Successfully ported and tested.

I2C_INT( ) – This function has all the initializations for the I2C port.


RTI_INT( ) - This function has all the initializations for the RTI. It is set to work for 8.192ms.


GPIO_INT( ) - This function has all the initializations for the GPIOs.


IN_LCD( ) - This function works on interrupt driven. It receives data from the touch screen.

This function resets the five minute counter in the RTI_ISR when ever it receives

an interrupt.


ADD_CART( ) - This function adds the user selected items into array called order depending on

the touch screen inputs. The touch screen inputs are compared to the menu1

A-37


predefined array. If the elements match with the input, the corresponding order

number is added to the array ‘order’.


OUT_LCD( ) - This function displays the string on the LCD at the specified location given X

and Y coordinates.


DISP_CART( ) – This function displays total order of the customer on the LCD screen. This

function is called when user hits ‘done’ on the touch screen.


WAIT( ) - This function waits for the specified number of ms.


IN_RFID( ) – This function waits for RFID tag. When it detects RFID tag it sends the data to

microcontroller using SCI0.


OUT_ZIGBEE( ) – This function sends data to kitchenette server using ZigBee transceiver.


IN_ZIGBEE( ) – This function receives data to kitchenette server using ZigBee transceiver

using SCI1.


CLEAN_UP( ) – This functions clears two arrays. Those are ‘sendArray’ and ‘order’.

‘sendArray’ has order and the RFID tag number combined together. ‘Order’ has

the user selected menu items.


TOTAL_CALC( ) – This function calculates the real time total of the cart and updates it when

ever user selects an item from the menu.


OUT_LCD_COM( )- This function sends commands to LCD screen to display corresponding

LCD screens for the customized menu depending on the RFID tag number.


A-38


BATT_CALC( ) – This function calculates the battery level using max1660 chip. This is

interfaced to I2C of the microcontroller. This function is called by RTI_ISR

every minute.


BATT_DISP( ) – This functions displays the battery information. It displays both percentage of

charge left and the three bars representing the charge levels. If charge is in-

between 100- 66 % three bars are shown. If charge is in between 66- 33 two

bars are shown else one bar is shown. This function displays warning message

when charge is below 10% and it shut downs the entire system when charge is

less than 5%. This function is called by RTI_ISR every minute.


RTI_ISR( ) - This function has RTI subroutine written. It has two counters. First counter is used

to measure a minute and call BATT_CALC and BATT_DISP functions. Second

counter is used to measure five minutes and call the Sleep_Set function.


SLEEP_SET( ) - This function is used to switch off the back light of the LCD.


The software for the host computer is written in C#.NET. The host PC software is used to

receive information and commands from the microcontroller and is used to send information to

the microcontroller about validation of the RFID tag, menu customization etc. At the host

computer a database is also planned to be implemented in SQL Server that bears the information

about the different menu items and the RFID tags that are registered to the system.

11.0 Version 2 ChangesThe version 2 of the ‘Touch 2 Order’ will include many other features that are not there in

the present version. Windows surface has always been our inspiration in designing the ‘Touch 2

Order’. Due to lack of high technology and appropriate funding we weren’t able to spend much

on the project. Given a chance for upgrade, our team is very much interested to create a multi-

touch interface which makes ordering food more fun and easy. A feature such as drag and drop

where the user can drag items and drop them in the cart to place the order would be a good one.

A-39


In the present version updating of the menu is hard for the restaurant owner because the

microcontroller needs to be programmed every time a change is needed. For version 2 our team

has decided to make it easier for the restaurant owner to make changes in the menu where he

could do it directly from the host server. Addition of a credit card reader along with the RFID

reader would also be a good idea provided that the security issues concerned with it are taken

care off.

Also the version 2 would be designed more compact and sleek than the earlier version. For

this the battery circuit should be redesigned and we are opting to use lithium ion batteries than

the NiMH rechargeable AA batteries as they are considered safer and also have better

performance. For this the PCB needs to be designed again to make it more compact. Even though

it may make the product expensive an addition of graphics card is also considered by our team to

display more graphics on the touch screen which gives a pleasant visual experience for the users.

The ‘Touch 2 Order’ has all the minimal features that fulfill the purpose it is designed for.

Addition of the above mentioned features could only make it much better.

12.0 Summary and Conclusions‘Touch 2 Order’ was an idea sometime back. To make it into reality we needed to learn so

much and work hard for a semester. The tough job at the starting was on what project to do.

Finally our team has decided to do something like the windows surface. But due to lack of many

things such as funds, time and technology we compromised ourselves to minimize the features

and started to design the ‘Touch 2 Order’. It needed a lot of research on the main components

such as the display screen, RFID reader, a wireless transceiver, microcontroller and other

components. It was a tough job to find the right component we needed making all the

considerations such as packaging, cost etc.

After the selection of components the next thing was to design the circuit using the

schematic. Although we had previous experience in Orcad Capture, we needed to learn a lot of

new things such as creating new parts, a net list which is needed for PCB Layout etc. Next thing

was even tough and most important in the design. The PCB layout is the heart of the project. A

small mistake in the design could make the device to fail. None of our team members had

previous experience in Layout Plus. So the PCB design took a lot of time.

A-40


After the midterm design review we made a major change in our project, that is to add a

battery charger and monitor circuit to make the device more portable which again was a time

consuming thing at that stage of the design. Next in line was the software. We did a lot of coding

in Code Warrior for the microcontroller and Hyper Terminal for the LCD screen. None of us had

experience in this software. So it was again a new learning experience. Once we got our PCB

manufactured we populated it with all the components. Soldering was a tough job although we

had some previous experience during ECE 362 this was all together a different kind of a thing.

After everything was into place and we successfully demonstrated our PSSC’s it was time

for the final packaging of the product. Since everything was working fine packaging of the

product was a minor issue. So finally after a semester long of hard work we were able to make

our thoughts into reality with the help of a good course curriculum and assisting teaching staff.

A-41


13.0 References

[1] Atmel ATmega64RZAPV ZigBee datasheethttp://www.atmel.com/dyn/resources/prod_documents/doc5131.pdf

[2] Sparkfun RFID data sheet ID-12http://www.sparkfun.com/datasheets/Sensors/ID-12-Datasheet.pdf

[3] Sparkfun RFID LF tagshttp://www.sparkfun.com/commerce/product_info.php?products_id=8310

[4] TI RFID series micro 2000 reader module http://focus.ti.com/lit/ds/symlink/ri-stu-mrd1-30.pdf

[5] Reach Technology touch screen SLCD5http://www.reachtech.com/display/slcd5.html

[6] Apollo Display Technologies touch screen

http://www.apollodisplays.com/Products/TFTDisplays/SelectApolloWhiteLED.html?KitNum=T-51638D084J-FW-A-AB-V399

[7] Freescale 16-bit microcontroller Data sheethttp://www.freescale.com/files/microcontrollers/doc/data_sheet/MC9S12E128V1.pdf?fpsp=1

[8] Atmel ATmega1280 8-bit microcontroller datasheethttp://www.atmel.com/dyn/resources/prod_documents/2549S.pdf

[9] Microchip 16-bit microcontroller datasheethttp://ww1.microchip.com/downloads/en/DeviceDoc/70287A.pdf

[10] XBee RF module data sheet http://ftp1.digi.com/support/documentation/90000866_A.pdf

[11] IBM Sure POS 700 Series overview and technical specifications http://www-03.ibm.com/products/retail/products/pos/700/features.html

[12] Microworks POS Solutions Inc. Tableside POS http://www.microworks.com/products/Handheld-Orderng.htm

[13] Pactec Enclosures http://www.pactecenclosures.com/Plastic-Enclosures/PT-8.html

[14] National Semiconductor DC to DC convertor http://www.national.com/pf/LM/LM2679.html

A-42

http://www.national.com/pf/LM/LM2679.html

http://www.pactecenclosures.com/Plastic-Enclosures/PT-8.html

http://www.microworks.com/products/Handheld-Orderng.htm

http://www-03.ibm.com/products/retail/products/pos/700/features.html

http://ftp1.digi.com/support/documentation/90000866_A.pdf

http://ww1.microchip.com/downloads/en/DeviceDoc/70287A.pdf

http://www.atmel.com/dyn/resources/prod_documents/2549S.pdf

http://www.freescale.com/files/microcontrollers/doc/data_sheet/MC9S12E128V1.pdf?fpsp=1

http://www.freescale.com/files/microcontrollers/doc/data_sheet/MC9S12E128V1.pdf?fpsp=1



http://www.reachtech.com/display/slcd5.html

http://focus.ti.com/lit/ds/symlink/ri-stu-mrd1-30.pdf

http://www.sparkfun.com/commerce/product_info.php?products_id=8310

http://www.sparkfun.com/datasheets/Sensors/ID-12-Datasheet.pdf

http://www.atmel.com/dyn/resources/prod_documents/doc5131.pdf


[15] Portable point of sale terminal (US Patent #: 5408077)

http://www.freepatentsonline.com/5408077.html

[16] Apparatus for order entry in a restaurant (US Patent #: 5003472)


[17] Customer self-ordering system using information displayed on a screen

(US Patent #: 5235509)


[18] Military Handbook, Reliability Prediction of Electronic Equipment, Department of Defense, 2 January 1990.

http://cobweb.ecn.purdue.edu/~dsml/ece477/Homework/CommonRefs/Mil-Hdbk-217F.pdf

[19] DC-DC voltage regulator MAX 1651 Data sheet http://cobweb.ecn.purdue.edu/~477grp13/docs/max1649-max1651.pdf

[20] Battery Fuel Gauge MAX 1660 Data sheet http://cobweb.ecn.purdue.edu/~477grp13/docs/max1660.pdf

[21] Finding and dealing with battery leakage/corrosion http://www.flippers.com/battery.html

[22] Wikipedia, Restriction of Hazardous Substances Directive http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive

[23] Environmental Health & Safety Inc. http://www.ehsservices.com/Services.htm

[24] Battery Solutions Inc. http://www.batteryrecycling.com/

A-43

http://www.batteryrecycling.com/

http://www.ehsservices.com/Services.htm

http://en.wikipedia.org/wiki/Restriction_of_Hazardous_Substances_Directive

http://cobweb.ecn.purdue.edu/~477grp13/docs/max1660.pdf

http://cobweb.ecn.purdue.edu/~477grp13/docs/max1649-max1651.pdf



http://www.freepatentsonline.com/5235509.html%20




Appendix A: Individual Contributions

A.1 Contributions of Varun Vallabhaneni:

My Contribution to the project started when our team formed last semester during the

end of Fall 2008. We had various ideas before we started working on the ‘Touch 2 Order’. I was

one of the persons who insisted that we should go ahead with the wireless touchscreen interfaced

restaurant ordering system. Within the first week we finalized our project proposal and decided

the ‘Touch 2 Order’ as our project.

As soon as the project took off, I started research on the components we needed and

the technology we wanted to use along with other team members. I did research on the touch

screen display we wanted to use. I discussed with other team members about the use of Zig Bee

wireless technology and RFID interfacing. I also did some research on the microcontroller we

wanted to use and discussed with others to use the Freescale MC9S12C32 16-bit microcontroller.

Once we decided and bought the components then it was the time to design the

schematic. I designed some of the parts of the schematic with the help of other team members.

Lot of new parts were needed to be created and many errors were fixed. Then I helped Srichand

in doing the PCB Layout which was the toughest job. Since we didn’t know the basics of Layout

Plus it took us a lot of time to figure out many things. Once we successfully completed the PCB,

the midterm design review led to many changes in our design. One of the main changes was the

addition of battery circuit. I did research on the level translator and charging circuit. I designed

the circuit for the level translator but later we found out that there was no need for that. Then I

had my share of contribution in redesigning the schematic and PCB Layout.

After Spring Break, it was time to start the software part of the project. Though I

didn’t do much of the software coding, I was contributing towards the PCB population and

hardware testing and debugging. Madhu and I soldered the PCB and tested different circuits one

after another debugging them. Finally after we got everything into place I contributed a lot

towards packaging, the final demo and report. My contribution in this project is more inclined

towards hardware than software.

A-44


A.2 Contributions of Anvesh Dasari:

I started working on our team project starting end of fall’08. The concept of Microsoft

surface drives us to develop a touch screen ordering system. I started this semester researching

different kinds of parts. I concentrated on choosing Zigbee wireless transceiver. I found Atmel

transceiver at first. Later my team decided to use Digi’s Xbee Pro. I did research on battery

charging circuit too.

I understood the zigbee technology. I did the schematic for the Xbee. I understood

how the MAX 712 chip works. I draw the schematic for 10 cells and 24v wall wart input. I spent

time on understanding the Layout software. I did layout for our schematic. I am able to do the

foot prints for the components which don’t have footprints. I helped the team in routing the

power, ground lanes.

Even though I worked on hardware side of the project by designing schematic and

doing layout, my major contributions include programming the microcontroller. Our team got

development board and I started working on SCI interface. I did my research on SCI. My

knowledge of 362 helped me to implement SCI interface. I learnt assembly C so that we can do

more effective coding

I worked on RTI interrupt. I spent lot of time understanding interrupts. I also spent

time on having both SCI and RTI interrupts work same time. I started the main programming for

our project with SCI interface. I am able communicate with the LCD screen. I started working on

the main program of adding items to order cart. Remove items from the order cart. I developed

several other small functions in assembly c for our project. I did research on I2C. I wrote code in

c for I2C interface of our microcontroller to the battery monitoring unit.

I have spent significant amount of time in hardware debugging too. I used to help my

team mates in debugging power circuits. Overall, I worked more software side of the project than

hardware. I learnt lot of interesting things while contributing to the project.

A-45


A.3 Contributions of Srichand Yella:At the end of fall 2008 semester, I had two ideas in mind for our project. I was

thinking of making a Home Automation system which controlled all the essential parts in a

house. But upon talking to Prof. Meyer we realized how easy the project was. So we took up the

Touch2Order project. At the beginning of spring 2008 semester, I started off by researching for

the parts that are needed for our system. I researched a lot of touch screens and finally came up

with the Reach Technologies SLCD5 controller. Initially I was trying to understand how the 4-

wire resistive touch screen worked, but now I have realized how easy it is work with the SLCD5

controller. All the low level controlling is already taken care of and all we had to do was to

simply call some functions to make the screen in a matter of minutes.

After the research, I spent most of my time working on making the circuit for our

system. I made the circuits for the MAX1651, MAX1649, MAX1660, the graphic controller, the

RFID reader and the ZigBee transceiver. Interfacing the graphic controller, RFID reader and the

ZigBee were all similar because all the devices used SCI interface with the microcontroller. I

also made the schematic for the microcontroller.

Later into the semester I spent a lot of my time on designing the PCB layout. Initially I

made one PCB layout but after Prof. Meyer suggested us to use battery power for our system, we

had to make a completely new PCB layout including some new footprints. We had a hard time

choosing the right parts for the PCB as some of the parts that were recommended were outdated

and were not available.

After we were done with all the hardware stuff and the PCB, we started working on

the software. While Madhu helped me make images for our system in Photoshop, I developed

the code for the touch screen graphics. After we had the touch screen and the RFID reader up

and running, we had some problem with the interfacing of the ZigBee. So, I worked on the

ZigBee and got it working. Now that we are able to communicate with the host computer, I

started to write the code for it in Visual C#. I also developed a database for storing all the

information about RFIDs and the Menu items.

During the last part of the semester, I mostly worked on debugging the circuits on the

PCB. We did have some errors on the PCB and finding and fixing these errors was a big deal.

Finally we have everything working, the software, the hardware, the interfacing, and the whole

system thanks to the team.

A-46


A.4 Contributions of Madhu Tummala:

When we initially formed the team, I thought of Restaurant ordering System as our

project but then there were many idea also other than mine. However, we ended up with the

Restaurant Ordering System (T2O). At the beginning of the Course, I did a lot of research on

what components to go and what special features to have in our project. I was responsible for

selecting the Zigbee’s technology Xbee pro and the SparkFun RFID.

During the design of circuits in the schematic I helped others selecting the right

resistor values and other parts, went through the data sheets of the parts thoroughly and

calculated the values of parts like resistors, capacitors and so on. I spent a lot of time figuring out

what parts to select for the battery circuit. I recommended the parts MAX712 for the battery

charger, MAX1600 for the battery monitor MAX1649 for the LDO circuit. I understood how

these parts work and helped others to design the schematic for those parts. I also designed the

RS232 (level shifter) interface circuit between Microcontroller and Touch screen.

I didn’t get to help a lot in the PCB layout. However, I understood how it works and

gave some suggestions to my team members. I designed graphics using adobe Photoshop for the

Touch Screen.

I did a lot of research on I2C and understood how it works. I and Anvesh worked on the

I2C interface for our battery monitor. I and Anvesh went through most of the programming

together and I helped him in the debugging especially in SCI. I and Srichand worked a lot on

debugging the battery circuit and Xbee pro.

I did the most of the soldering of parts on the PCB, it was a very tough job and I had to be

very careful. Also not all parts go on our PCB because some of the parts have a different

packaging type than on the PCB. I did a lot of research figuring out what other right parts would

substitute those parts and if not how could it be made worked.

I helped a lot in the Packaging design and the final packaging. I have learned many things in

this project. Finally I would say, I sort of touched all parts of the project.

A-47


Appendix B: Packaging

Figure B-1 Different stages of Packaging from PCB to final product.

B-1


Appendix C: Schematic

Figure C-1 Microcontroller Schematic

Figure C-2 XBee Pro Schematic

C-1


Figure C-3 MAX 712 (Battery charger circuit) Schematic

C-2


Figure C-4 MAX 1651 and MAX 1649 (3.3 V and 5 V) voltage regulators Schematic

C-3


Figure C-5 MAX 1660 (Battery Monitor Circuit) Schematic

C-4


Appendix D: PCB Layout Top and Bottom Copper

Figure D-1 PCB Top Copper Layer

D-1


Figure D-2 PCB Bottom Copper Layer

D-2


Appendix E: Parts List Spreadsheet

Manufacturer Part No. Description CostReach Technologies 42-0105-01 8.7 inchTouchscreen LCD

display$ 699.00

Spark Fun Technologies

ID-12 RFID reader $ 29.95

Maxstream XBee Pro Zig Bee wireless transceiver $32.00Freescale 9S12E128 16 bit Microcontroller $14.90Pactec Enclosures DM - 4 Device Enclosure $33.00Digi Key & Mouser electronics

- Capacitors, Resistors, Inductors, MOSFETS and other passive components

$30.00

Only batteries NiMH batteries Accupower AA rechargeable batteries

$52.00

CUI Inc EPAS -101W-24 Switch mode power supply $19.00Total Cost of the project $909.85

Table E-1 Parts list and their individual costs and total cost of the project.

E-1


Appendix F: Software Listing

F-1 Software for Microcontroller/*************************************************** T20 software for micrcontroller version 1.1:Started on March 15th by Anvesh version 1.2:Updated by Anvesh on March 16th version 1.3:Updated by Anvesh on March 20th version 1.4:Updated by Srichand on April 6th version 2.1:Updated by Anvesh on April 8th version 2.2:Updated by Anvesh on April 10th version 2.3:Updated by Srichand on April 11th version 2.4:Updated by Madhu on April 16th version 3.1:Updated by Anvesh on April 18th version 3.2:Updated by Anvesh on April 20th version 3.3:Updated by Anvesh on April 22th ****************************************************/

#include <hidef.h> /* common defines and macros */#include <mc9s12e128.h> /* derivative information */#include <stdio.h>#include <string.h>

/* function prototypes*/void make_order (char);void TAKE_DATA (void);void OUT_LCD (char *a);void SCI2INT (void);void SCI0INT (void);void SCI1INT ( void);void RTIINT(void);void outc_test (char *a);void ADD_CART(char *a);void REMOVE_CART(char *a);void IN_RFID(char a[30]);//void wait(long a);void QUANT_CART(char *a);void SCI2_ISR(void);void wait(long ms);void IN_ZIGBEE(char a[160]);void OUT_ZIGBEE (char *a);void CLEAR_ORDER();void IICINT (void);void GET_BAT(void);/* Global Variables */int order[30]; // The item number of the user selected item is saved in this array.int order_quant[30]; // The quantity of the order is saved in this arrayint num;char rfid_tag[12]; // Input from RFID is saved in this arrayint rti_cnt; // Counter for RTIint sleep_flag;int sleep_cnt;int table = 7; // table number float bat = 0;char send_array[160]; // Array send over zigbeechar recieve_array[160]; //Array recieved over zigbeelong dis_count0; // Discharge count0 for the batterylong dis_count1; // Discharge count1 for the battery

F-1


long dis_count2; // Discharge count2 for the batterylong dis_count3; // Discharge count3 for the batterylong ch_count0; // Charge count0 for the batterylong ch_count1; // Charge count1 for the batterylong ch_count2; // Charge count2 for the batterylong ch_count3; // Charge count3 for the batterytypedef struct{ // struct type for an item. char abutton[10]; char item[30]; int number; int dollars; int cents; char bcmd[10]; char bnum[50];} record; // struct type to help in DISP_CART functiontypedef struct { char rbutton[5]; char dec_button[5]; char inc_button[5]; char disp_co[150]; char disp_co2[20]; char disp_co3[10];} disp_vector;

//T20 menu items datarecord menu[]={ {"s20 1","Bacon, Egg & Cheese Biscuit",1,5,99,"bd 20 "," 20 \"\" \"\" 0 0 0 0 30 31\r"}, {"s21 1","Egg McMuffin",2,6,0,"bd 21 "," 20 \"\" \"\" 0 0 0 0 32 33\r"}, {"s22 1","Hash Browns",3,4,0,"bd 22 "," 20 \"\" \"\" 0 0 0 0 34 35\r"}, {"s23 1","Hotcakes & Sausage",4,3,59,"bd 23 "," 20 \"\" \"\" 0 0 0 0 36 37\r"}, {"s24 1","Sausage Biscuit",5,4,23,"bd 24 "," 20 \"\" \"\" 0 0 0 0 38 39\r"}, {"s25 1","Sausage Biscuit with Egg",6,5,66,"bd 25 "," 20 \"\" \"\" 0 0 0 0 40 41\r"}, {"s26 1","Sausage McMuffin with Egg",7,4,0,"bd 26 "," 20 \"\" \"\" 0 0 0 0 42 43\r"}, {"s27 1","Coffee",8,2,0,"bd 27 "," 20 \"\" \"\" 0 0 0 0 44 45\r"}, {"s28 1","Hot Chocolate",9,4,0,"bd 28 "," 20 \"\" \"\" 0 0 0 0 46 47\r"}, {"s29 1","Ice Tea",10,4,0,"bd 29 "," 20 \"\" \"\" 0 0 0 0 48 49\r"}, {"s30 1","Water",11,0,0,"bd 30 "," 20 \"\" \"\" 0 0 0 0 50 51\r"}, {"s31 1","Coke",12,0,99,"bd 31 "," 20 \"\" \"\" 0 0 0 0 52 53\r"}, {"s32 1","Diet Coke",13,0,99,"bd 32 "," 20 \"\" \"\" 0 0 0 0 54 55\r"}, {"s33 1","Fanta",14,0,99,"bd 33 "," 20 \"\" \"\" 0 0 0 0 56 57\r"}, {"s34 1","Sprite",15,0,99,"bd 34 "," 20 \"\" \"\" 0 0 0 0 58 59\r"}};

disp_vector display_vector[] = { {"x42","x57","x58","\" 5 10\rbd 42 598 0 1 \"\" 0 0 62 63\rbd 57 460 1 1 \"\" 0 0 73 74\rxi 72 500 0\rbd 58 550 1 1 \"\" 0 0 75 76\r","\" 515 10\r","32 30"}, {"x43","x59","x60","\" 5 50\rbd 43 598 40 1 \"\" 0 0 62 63\rbd 59 460 41 1 \"\" 0 0 73 74\rxi 72 500 40\rbd 60 550 41 1 \"\" 0 0 75 76\r","\" 515 50\r","330 30"}, {"x44","x61","x62","\" 5 90\rbd 44 598 80 1 \"\" 0 0 62 63\rbd 61 460 81 1 \"\" 0 0 73 74\rxi 72 500 80\rbd 62 550 81 1 \"\" 0 0 75 76\r","\" 515 90\r","32 133"}, {"x45","x63","x64","\" 5 130\rbd 45 598 120 1 \"\" 0 0 62 63\rbd 63 460 121 1 \"\" 0 0 73 74\rxi 72 500 120\rbd 64 550 121 1 \"\" 0 0 75 76\r","\" 515 130\r","330 133"}, {"x46","x65","x66","\" 5 170\rbd 46 598 160 1 \"\" 0 0 62 63\rbd 65 460 161 1 \"\" 0 0 73 74\rxi 72 500 160\rbd 66 550 161 1 \"\" 0 0 75 76\r","\" 515 170\r","32 236"}, {"x47","x67","x68","\" 5 210\rbd 47 598 200 1 \"\" 0 0 62 63\rbd 67 460 201 1 \"\" 0 0 73 74\rxi 72 500 200\rbd 68 550 201 1 \"\" 0 0 75 76\r","\" 515 210\r","330 236"}, {"x48","x69","x70","\" 5 250\rbd 48 598 240 1 \"\" 0 0 62 63\rbd 69 460 241 1 \"\" 0 0 73 74\rxi 72 500 240\rbd 70 550 241 1 \"\" 0 0 75 76\r","\" 515 250\r","32 339"},

F-2


{"x49","x71","x72","\" 5 290\rbd 49 598 280 1 \"\" 0 0 62 63\rbd 71 460 281 1 \"\" 0 0 73 74\rxi 72 500 280\rbd 72 550 281 1 \"\" 0 0 75 76\r","\" 515 290\r","330 339"}, {"x50","x73","x74","\" 5 330\rbd 50 598 320 1 \"\" 0 0 62 63\rbd 73 460 321 1 \"\" 0 0 73 74\rxi 72 500 320\rbd 74 550 321 1 \"\" 0 0 75 76\r","\" 515 330\r","32 30"}, {"x51","x75","x76","\" 5 370\rbd 51 598 360 1 \"\" 0 0 62 63\rbd 75 460 361 1 \"\" 0 0 73 74\rxi 72 500 360\rbd 76 550 361 1 \"\" 0 0 75 76\r","\" 515 370\r","32 30"}};

void main(void) {

char ch[4];char dis[4];

/* put your own code here */ _asm ssinit: bclr CLKSEL,$80 // Busclock initializations_asm bset PLLCTL,$40_asm bclr PLLCTL,$80 // BUsclock is set for 24MHz_asm bset PLLCTL,$01_asm movb #$02,SYNR_asm movb #$00,REFDV_asm nop_asm nop_asm plllp: brclr CRGFLG,$08,plllp _asm bset CLKSEL,$80

_asm movb #$40,COPCTL DDRM=0xFF; _asm bset PTM,#$08 DDRAD=0x00; rti_cnt=0; sleep_cnt=0; sleep_flag=0; SCI2INT(); SCI1INT(); SCI0INT(); //IICINT(); RTIINT(); OUT_LCD("m 1\r"); /* for(;;) { GET_BAT(); ch[0] = ch_count0/10 + '0'; ch[1] = ch_count0%10 + '0'; ch[2] = '\0'; dis[0] = dis_count0/10 + '0'; dis[1] = dis_count0%10 + '0'; dis[2] = '\0'; outc_test(dis); } */

EnableInterrupts;

for(;;) { SCI2_ISR(); } /* wait forever */ /* please make sure that you never leave this function */}

F-3


/***************************************************************Function:IICINTInput parameters: voidOutput Parameters: VoidDescription:This has the I2C initializations***************************************************************/

void IICINT (void) { IBFD = 0x4C; IBAD = 0x00; IBCR = 0x80;}/***************************************************************Function:SCI2INTInput parameters: voidOutput Parameters: VoidDescription:This has the SCI 2 initializations***************************************************************/

void SCI2INT (void) { SCI2BDL=0x0D; SCI2CR2=0x0C; SCI2CR1=0x00; SCI2BDH=0x00; } /***************************************************************Function:SCI1INTInput parameters: voidOutput Parameters: VoidDescription:This has the SCI 1 initializations***************************************************************/ void SCI1INT (void) { SCI1BDL=0x0D;//(unsigned char)((24000000UL /* OSC freq */ / 2) / 9600 /* baud rate */ / 16 /*factor*/); ; SCI1CR2=0x0C; SCI1CR1=0x00; SCI1BDH=0x00;}/***************************************************************Function:SCI0INTInput parameters: voidOutput Parameters: VoidDescription:This has the SCI 0 initializations***************************************************************/ void SCI0INT (void) { SCI0BDL=0x9C; SCI0CR2=0x04; SCI0CR1=0x00; SCI0BDH=0x00; } /***************************************************************Function:RTIINTInput parameters: voidOutput Parameters: VoidDescription:This has the RTI initializations

F-4


***************************************************************/

void RTIINT(void) { CRGFLG=0x80; RTICTL=0x1F; CRGINT=0x80; _asm cli }

/***************************************************************Function:GET_BATInput parameters: voidOutput Parameters: VoidDescription:This function gets the Discharge count and charge count from the battery and converts it into % and display it to the screen***************************************************************/

void GET_BAT(void) { _asm bclr IBCR,#$08 //Enable Transmit Aknowledge _asm bset IBCR,#$30 //Enable Master Transmit while (!(IBSR & 0x20)); IBDR = 0b10001110; //Send slave address write while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //outc_test("first"); //while (IBSR & 0x01); //outc_test("second"); while (!(IBSR & 0x20)); IBDR = 0x04; //Write config the MAX1660 to discharge count while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); IBDR = 0x00; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); IBDR = 0x00; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); IBDR = 0x82; //Discharge count1 and count0 reading while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); _asm bset IBCR,#$04 IBDR = 0b10001111; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); _asm bclr IBCR,#$10

F-5


dis_count0 = IBDR; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 dis_count0 = IBDR; _asm bset IBCR,#$08 while (!(IBSR & 0x02)); _asm bset IBCR,#$02 _asm bclr IBCR,#$20 dis_count1 = IBDR; _asm bset IBCR,#$30 //Enable Master Transmit IBDR = 0x83; //Discharge count3 and count2 reading while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); _asm bset IBCR,#$04 IBDR = 0b10001111; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); _asm bclr IBCR,#$10 dis_count2 = IBDR; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 dis_count0 = IBDR; _asm bset IBCR,#$08 while (!(IBSR & 0x02)); _asm bset IBCR,#$02 _asm bclr IBCR,#$20 dis_count3 = IBDR; ///////////////////////////////////////////////////////////////////// _asm bclr IBCR,#$08 //Enable Transmit Aknowledge _asm bset IBCR,#$30 //Enable Master Transmit while (!(IBSR & 0x20)); IBDR = 0b10001110; //Send slave address write while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); while (!(IBSR & 0x20)); IBDR = 0x04; //Write config the MAX1660 to discharge count while (!(IBSR & 0x02));

F-6


_asm bset IBCR,#$02 //while (IBSR & 0x01); IBDR = 0x40; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); IBDR = 0x00; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); IBDR = 0x82; //Charge count1 and count0 reading while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); _asm bset IBCR,#$04 IBDR = 0b10001111; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); _asm bclr IBCR,#$10 ch_count0 = IBDR; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 ch_count0 = IBDR; _asm bset IBCR,#$08 while (!(IBSR & 0x02)); _asm bset IBCR,#$02 _asm bclr IBCR,#$20 ch_count1 = IBDR; _asm bset IBCR,#$30 //Enable Master Transmit IBDR = 0x83; //Charge count3 and count2 reading while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); _asm bset IBCR,#$04 IBDR = 0b10001111; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 //while (IBSR & 0x01); _asm bclr IBCR,#$10

F-7


ch_count2 = IBDR; while (!(IBSR & 0x02)); _asm bset IBCR,#$02 dis_count0 = IBDR; _asm bset IBCR,#$08 while (!(IBSR & 0x02)); _asm bset IBCR,#$02 _asm bclr IBCR,#$20 ch_count3 = IBDR; ////////////////////////////////////////////////////////////////////}/***************************************************************Function:OUT_LCDInput parameters: char *aOutput Parameters: VoidDescription:This function sends data to LCD through SCI2 port***************************************************************/ void OUT_LCD (char *a){ while (*a != '\0') { while (!(SCI2SR1 & 0x80)); SCI2DRL = *a++; }}

/***************************************************************Function:outc_testInput parameters: char *aOutput Parameters: VoidDescription:This function displays the text at 0 0 location on touchscreen***************************************************************/

void outc_test (char *a){ OUT_LCD("t \""); OUT_LCD(a); OUT_LCD("\" 0 0\r");}

/***************************************************************Function:ADD_CARTInput parameters: char *aOutput Parameters: VoidDescription:adds the item number in the array order depending on the user input***************************************************************/

void ADD_CART(char *a){ int i=0; while (i <= sizeof(menu)) {

F-8


if (strcmp(a,menu[i].abutton) == 0) { order[num]= menu[i].number; order_quant[num]=1; outc_test(menu[i].item); num++; } i++; }}/***************************************************************Function:REMOVE_CARTInput parameters: char *aOutput Parameters: VoidDescription:removes the item number in the array order depending on the user input***************************************************************/

void REMOVE_CART(char *a) {int j=0;char b[] = "t \"";

while (j <= sizeof(display_vector)){ if (!strcmp(a,display_vector[j].rbutton)) { outc_test("founddddd"); while( j <= num) { order[j]=order[j+1]; order_quant[j]=order_quant[j+1]; j++; } } j++; }}/***************************************************************Function:QUANT_CARTInput parameters: char *aOutput Parameters: VoidDescription:updates quantity of the the item in the array order_quant depending on the user input***************************************************************/ void QUANT_CART(char *a) { int dollar_total=0; int cent_total=0; int k=0; char total_text[10]; char total_quant[5]; int j = 0; int i =1000; int temp; int temp2=0; while (k <=7){ if (!strcmp(a,display_vector[k].inc_button)) { if (order_quant[k] < 9){ order_quant[k]++; total_quant[0]=order_quant[k]+'0'; total_quant[1]='\0'; OUT_LCD("t \""); OUT_LCD(total_quant);

F-9


OUT_LCD(display_vector[k].disp_co2); } } if (!strcmp(a,display_vector[k].dec_button)) { if (order_quant[k] > 1){ order_quant[k]--; total_quant[0]=order_quant[k]+'0'; total_quant[1]='\0'; OUT_LCD("t \""); OUT_LCD(total_quant); OUT_LCD(display_vector[k].disp_co2); } } dollar_total = dollar_total + menu[order[k]-1].dollars*order_quant[k]; cent_total = cent_total + menu[order[k]-1].cents*order_quant[k]; k++; } if (cent_total > 99) { dollar_total = dollar_total + cent_total/100; } cent_total = cent_total%100; temp=dollar_total; if (dollar_total == 0) { total_text[j++] = '0'; } while (i > 0) { if (temp/i>0 || temp2 == 1) { total_text[j]=temp/i+'0'; temp=temp%i; j++; temp2=1; } i=i/10; } total_text[j++]= '.'; i=100; temp=cent_total; if (cent_total == 0) { total_text[j++] = '0'; total_text[j++] = '0'; } while (i > 0) { if (temp/i>0) { total_text[j++]=temp/i+'0'; temp=temp%i; } i=i/10; } total_text[j]= '\0'; OUT_LCD("t \"$"); OUT_LCD(total_text);

F-10


OUT_LCD("\" 535 450\r"); }/***************************************************************Function:DISP_CARTInput parameters: voidOutput Parameters: VoidDescription:Displays the cart on to the LCD screen using order and order_quant arrays***************************************************************/ void DISP_CART(void) {int k=0;int dollar_total = 0;int cent_total = 0;char total_text[10];char total_quant[5];int j = 0;int i =1000;int temp;int temp2=0; OUT_LCD("m 13\r"); while (k <= 7) { if (menu[order[k]-1].number == order[k]) { OUT_LCD("t \""); OUT_LCD(menu[order[k]-1].item); OUT_LCD(display_vector[k].disp_co); total_quant[0]=order_quant[k]+'0'; total_quant[1]='\0'; OUT_LCD("t \""); OUT_LCD(total_quant); OUT_LCD(display_vector[k].disp_co2); wait(150); dollar_total = dollar_total + menu[order[k]-1].dollars*order_quant[k]; cent_total = cent_total + menu[order[k]-1].cents*order_quant[k]; } k++; } if (cent_total > 99) { dollar_total = dollar_total + cent_total/100; } cent_total = cent_total%100; temp=dollar_total; if (dollar_total == 0) { total_text[j++] = '0'; } while (i > 0) { if (temp/i>0 || temp2 == 1) { total_text[j]=temp/i+'0'; temp=temp%i; j++; temp2=1; } i=i/10; } total_text[j++]= '.'; i=100; temp=cent_total;

F-11


if (cent_total == 0) { total_text[j++] = '0'; total_text[j++] = '0'; } while (i > 0) { if (temp/i>0) { total_text[j++]=temp/i+'0'; temp=temp%i; } i=i/10; } total_text[j]= '\0'; OUT_LCD("t \"$"); OUT_LCD(total_text); OUT_LCD("\" 535 450\r"); }/***************************************************************Function:CLEAR_ORDERInput parameters: voidOutput Parameters: VoidDescription:Order is initialized to null when all the ordered items are sent to the server and confirmation is recieved from the server.***************************************************************/

void CLEAR_ORDER(void){ int i = 0; num = 0; for (i = 0; i<sizeof(order); i++) { order[i] = 0; } for (i = 0; i<sizeof(order_quant); i++) { order_quant[i] = 0; } for (i = 0; i<sizeof(send_array); i++) { send_array[i] = '\0'; } for (i = 0; i<sizeof(recieve_array); i++) { recieve_array[i] = '\0'; } for (i = 0; i<sizeof(rfid_tag); i++) { rfid_tag[i] = '\0'; }}

/***************************************************************Function:IN_RFIDInput parameters: char *aOutput Parameters: VoidDescription: This function is used to get the RFID tag number from the reader. This is program driven and used SCI0 . The tag id is saved in rfid_tag array.***************************************************************/

void IN_RFID(char a[30]) {

F-12


char I=-1; char J = 0;

do{ while (!(SCI0SR1 & 0x20)); if (SCI0DRL == '0') { I++; a[I] = SCI0DRL; while (SCI0DRL != 0x0D) { while (!(SCI0SR1 & 0x20)); I++; J = 1; a[I] = SCI0DRL; } }} while (J == 0); I++;a[I]='\0'; outc_test(a);}

/***************************************************************Function:IN_ZIGBEEInput parameters: char *aOutput Parameters: VoidDescription:This functions recives data from Zigbee transciever through SCI1. the data is saved in recieve_array***************************************************************/

void IN_ZIGBEE(char a[160]) { char I=-1; char J = 0; PTT= 0x40;

do{ while (!(SCI1SR1 & 0x20)); if (SCI1DRL == '[') { I++; a[I] = SCI1DRL; while (SCI1DRL != ']') { while (!(SCI1SR1 & 0x20)); I++; J = 1; a[I] = SCI1DRL; } }} while (J == 0); I++;a[I]='\0';outc_test(a);}

/***************************************************************Function:OUT_ZIGBEEInput parameters: char *aOutput Parameters: Void

F-13


Description:This functions sends data to Zigbee transciever through SCI1. The data is sent through send_array***************************************************************/

void OUT_ZIGBEE (char *a){ while (*a != '\0') { while (!(SCI1SR1 & 0x80)); PTT=0x80; SCI1DRL = *a++; }}

/***************************************************************Function:make_orderInput parameters: char sOutput Parameters: VoidDescription:This function creates send_array depending on the char s is s=1 we will send RFID tag number order and table number s=2 we send RFID tag number s=3 we send only order***************************************************************/

void make_order (char s) { int ii; int j; int k=0; send_array[k++] = s; send_array[k++] = '>'; if (s != '2'){ for (j=0; j < sizeof(rfid_tag); j++){ send_array[k++] = rfid_tag[j]; } send_array[k++] = '>'; } if (s == '1') { for (ii = 0; ii < num ; ii++) { send_array[k++] = order[ii]/10 + '0'; send_array[k++] = order[ii]%10 + '0'; send_array[k++] = ':'; send_array[k++] = order_quant[ii] + '0'; send_array[k++] = ','; } send_array[k++] = '>'; send_array[k++] = table + '0'; send_array[k++] = '\0'; } else if (s == '0') { send_array[k++] = '\0'; } else if (s == '2'){ send_array[k++] = '>'; for (ii = 0; ii < num ; ii++) { send_array[k++] = order[ii]/10 + '0'; send_array[k++] = order[ii]%10 + '0'; send_array[k++] = ':'; send_array[k++] = order_quant[ii] + '0';

F-14


send_array[k++] = ','; } send_array[k++] = '>'; send_array[k++] = table + '0'; send_array[k++] = '\0'; }

}

/***************************************************************Function:TAKE_DATAInput parameters: voidOutput Parameters: VoidDescription:this function uses recieve_array and gets the user preferances. his balances and display that to screen.***************************************************************/

void TAKE_DATA(void) {int ii=1;char name_array[100];char balance_array[10];int j=0;int i=0;int k=0;char temp;char temp1;char temp2[3];

if (recieve_array[1] == '0'){ OUT_LCD("m 13\r"); }else if (recieve_array[1] == '1'){ ii++; ii++; while (recieve_array[ii] != '>'){ name_array[j++]=recieve_array[ii++]; } name_array[j]='\0'; j=0; ii++; while(recieve_array[ii] != ']'){ balance_array[j++]=recieve_array[ii++]; } balance_array[j]='\0'; OUT_LCD("m 13\r"); OUT_LCD("t \""); OUT_LCD(name_array); OUT_LCD("\" 300 10\r"); OUT_LCD("t \""); OUT_LCD(balance_array); OUT_LCD("\" 300 400\r"); CLEAR_ORDER(); }else if (recieve_array[1] == '2'){ ii++; ii++; while (recieve_array[ii] != '>'){ name_array[j++]=recieve_array[ii++]; } name_array[j]='\0'; j=0; ii++;

F-15


while(recieve_array[ii] != ']'){ balance_array[j++]=recieve_array[ii++]; } balance_array[j]='\0'; OUT_LCD("m 13\r"); OUT_LCD("t \""); OUT_LCD(name_array); OUT_LCD("\" 300 10\r"); OUT_LCD("t \"Sufficient funds not avialable\" 300 200\r"); OUT_LCD("t \""); OUT_LCD(balance_array); OUT_LCD("\" 300 400\r"); }else if (recieve_array[1] == '3'){ OUT_LCD("m 13\r"); OUT_LCD("t \"Order Placed\" 200 200\r"); CLEAR_ORDER(); }else if (recieve_array[1] == '5'){ OUT_LCD("m 13\r"); OUT_LCD("t \"Invalid RFID Tag\" 200 200\r"); }else if (recieve_array[1] == '4') { ii++; ii++; OUT_LCD("m 13\r"); while (recieve_array[ii] != '>'){ name_array[j++]=recieve_array[ii++]; } name_array[j]='\0'; ii++; j = 0; while (recieve_array[ii] != ']' && j<8) { temp = recieve_array[ii++]; temp1 = recieve_array[ii++]; if (temp == '0' && temp1 == '1') k = 1; else if (temp == '0' && temp1 == '2') k = 2; else if (temp == '0' && temp1 == '3') k = 3; else if (temp == '0' && temp1 == '4') k = 4; else if (temp == '0' && temp1 == '5') k = 5; else if (temp == '0' && temp1 == '6') k = 6; else if (temp == '0' && temp1 == '7') k = 7; else if (temp == '0' && temp1 == '8') k = 8; else if (temp == '0' && temp1 == '9') k = 9; else if (temp == '1' && temp1 == '0') k = 10; else if (temp == '1' && temp1 == '1') k = 11; else if (temp == '1' && temp1 == '2') k = 12; else if (temp == '1' && temp1 == '3') k = 13;

F-16


else if (temp == '1' && temp1 == '4') k = 14; else if (temp == '1' && temp1 == '5') k = 15; OUT_LCD(menu[k-1].bcmd); OUT_LCD(display_vector[j++].disp_co3); OUT_LCD(menu[k-1].bnum); wait(150); ii++; } }}/***************************************************************Function:SCI2_ISRInput parameters: voidOutput Parameters: VoidDescription:This function recives data continously.depending on the recived data different function are called.

***************************************************************/ void SCI2_ISR(void){ static char a[7]; char I=-1; char J = 0; do{ while (!(SCI2SR1 & 0x20)) { } if (SCI2DRL == 's' || SCI2DRL == 'r' || SCI2DRL == 'x') { I++; a[I] = SCI2DRL; sleep_flag=1; while (a[I] != '\r') { while (!(SCI2SR1 & 0x20)); I++; J = 1; a[I] = SCI2DRL; } } }while (J == 0); *(a+I)='\0'; OUT_LCD("t \""); OUT_LCD(a); OUT_LCD("\" 0 0\r"); if (a[0] == 's') { ADD_CART(a);} else if (strcmp(a,"r36")==0) { OUT_LCD("m 13\r"); DISP_CART();} else if (strcmp(a,"r37")==0) { OUT_LCD("m 14\r"); DISP_CART();} else if (strcmp(a,"r38")==0) { OUT_LCD("m 15\r"); DISP_CART();} else if (strcmp(a,"r39")==0) { OUT_LCD("m 16\r");

F-17


DISP_CART();} else if (strcmp(a,"r40")==0) { OUT_LCD("m 17\r"); DISP_CART();} else if (strcmp(a,"r41")==0) { OUT_LCD("m 18\r"); DISP_CART();}else if (!strcmp(a,"x42") || !strcmp(a,"x43") || !strcmp(a,"x44") || !strcmp(a,"x45") || !strcmp(a,"x46") || !strcmp(a,"x47") || !strcmp(a,"x48") || !strcmp(a,"x49") || !strcmp(a,"x50") || !strcmp(a,"x51")){ REMOVE_CART(a); num--; DISP_CART();}else if (!strcmp(a,"r1")){ IN_RFID(rfid_tag); make_order('0'); OUT_ZIGBEE(send_array); IN_ZIGBEE(recieve_array); TAKE_DATA();} else if (a[0]== 'x'){ QUANT_CART(a);} else if (!strcmp(a,"r55")){ DISP_CART();}else if (!strcmp(a,"r53")){ IN_RFID(rfid_tag); make_order('1'); OUT_ZIGBEE(send_array); IN_ZIGBEE(recieve_array); TAKE_DATA();}else if(!strcmp(a,"r54")){ make_order('2'); OUT_ZIGBEE(send_array); IN_ZIGBEE(recieve_array); outc_test("first222222222222"); TAKE_DATA(); }}

/***************************************************************Function:RTI_ISRInput parameters: voidOutput Parameters: VoidDescription: This function works on interrupt mode for every 8.192 ms. it increments rti_cnt every time it enters this function.***************************************************************/ #pragma CODE_SEG __NEAR_SEG NON_BANKED

interrupt 7 void RTI_ISR(void) {

CRGFLG=0x80; rti_cnt++; sleep_cnt++; if (sleep_flag == 1) { sleep_flag=0; sleep_cnt=0; } if (sleep_cnt > 250000) { OUT_LCD("m 15\r"); }

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}/***************************************************************Function:waitInput parameters: long msOutput Parameters: VoidDescription:This function waits for specified number of ms. This is used in DISP_CART to send data correctly.***************************************************************/

#pragma CODE_SEG DEFAULT

void wait(long ms){ long timeout; timeout = rti_cnt + ms; while (timeout > rti_cnt) { __asm NOP /* __asm WAI; */ /* will be waken up by the RTI exception. Not well supported in BDM mode */ }}

F-2 Software for the Host system where the order is received:

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Data.Common;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.IO.Ports;using System.Threading;using System.Data.SqlClient;

namespace Touch2Order{ public partial class Form1 : Form { // Default Port Settings SerialPort port = new SerialPort("COM3", 115200, Parity.None, 8, StopBits.One);

public Form1() { InitializeComponent();

// Populate the portName comboBox with available ports names portName.Items.Clear(); foreach (string s in SerialPort.GetPortNames()) { portName.Items.Add(s); }

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// Load the previous settings into the form portName.Text = Properties.Settings.Default.portName; baudRate.Text = Properties.Settings.Default.baudRate.ToString(); parity.Text = Properties.Settings.Default.parity; dataBits.Text = Properties.Settings.Default.dataBits.ToString(); stopBits.Text = Properties.Settings.Default.stopBits; }

private void applyButton_Click(object sender, EventArgs e) { try { if (port.IsOpen == true) { port.Close(); }

// Set port name port.PortName = portName.Text;

// Set Baud Rate port.BaudRate = Convert.ToInt32(baudRate.Text);

// Set parity if (parity.Text.Equals("Even")) { port.Parity = Parity.Even; } else if (parity.Text.Equals("Mark")) { port.Parity = Parity.Mark; } else if (parity.Text.Equals("None")) { port.Parity = Parity.None; } else if (parity.Text.Equals("Odd")) { port.Parity = Parity.Odd; } else if (parity.Text.Equals("Space")) { port.Parity = Parity.Space; }

// Set Data Bits port.DataBits = Convert.ToInt16(dataBits.Text);

// Set Stop Bits if (stopBits.Text.Equals("One")) { port.StopBits = StopBits.One; } else if (stopBits.Text.Equals("Two")) { port.StopBits = StopBits.Two; }

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if (port.IsOpen == false) { port.Open(); } } catch (Exception ex) { // If any exceptions, display a MessageBox MessageBox.Show(ex.Message); } }

private void Form1_FormClosing(object sender, FormClosingEventArgs e) { // Save the port settings before closing Properties.Settings.Default.portName = port.PortName; Properties.Settings.Default.baudRate = port.BaudRate; Properties.Settings.Default.parity = port.Parity.ToString(); Properties.Settings.Default.dataBits = port.DataBits; Properties.Settings.Default.stopBits = port.StopBits.ToString(); port.Close(); }

private void Form1_Load(object sender, EventArgs e) { // When form loads, initiate all the table adapters this.menuTableAdapter1.Fill(projectDataSet1.Menu); this.rfiD_tagsTableAdapter1.Fill(projectDataSet1.RFID_tags);

// Run the recieve function in the background not to hang up the main // window Thread recieve_input = new Thread(new ThreadStart(this.recieve)); recieve_input.IsBackground = true; recieve_input.Start(); }

private void send(string send_data) { // Sends the data to the port port.Write(send_data); }

private void recieve() { // Recieves the data from the port try { port.DataReceived += new SerialDataReceivedEventHandler(port_DataReceived); port.Open(); Application.Run(); } catch (Exception ex) { // If any exceptions, display a MessageBox MessageBox.Show(ex.Message); } }

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private double total(string order) { // Calculate the total for the order and return double tot = 0; int i = 0; int j = 1;

// Splits the order array into order items and quantity // to calculate the total for the order string[] orderArray = order.Split(new char[] { ':', ',' }); for (int k = 1; k <= (orderArray.Length / 2); k++) { tot = tot + Convert.ToDouble(projectDataSet1.Menu.Rows.Find(orderArray[i]).ItemArray[2]) * Convert.ToDouble(orderArray[j]); i = i + 2; j = j + 2; } return tot; }

delegate void SetBalanceCallback(string bal); private void SetBalance(string bal) { // Set the new balance into the balanceTextBox for the RFID ShowRFIDTab(); if (this.balanceTextBox.InvokeRequired) { SetBalanceCallback d = new SetBalanceCallback(SetBalance); this.Invoke(d, new object[] { bal }); } else { this.balanceTextBox.Text = bal; } ClickSave(); }

delegate void DisplayOrderCallback(string ord, string tab, string pay); private void DisplayOrder(string ord, string tab, string pay) { // Displays the order in the multiline textbox.

// This function is called through a delegate, since the // textbox is defined in a different thread. double tot; int i = 0; string[] ordArray = ord.Split(new char[] { ':', ',' });

if (this.displayTextBox.InvokeRequired) { DisplayOrderCallback d = new DisplayOrderCallback(DisplayOrder); this.Invoke(d, new object[] { ord, tab, pay }); } else { // Display the header for the order displayTextBox.AppendText("Order for Table # " + tab + ":");

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// Goes to a new line in the textbox displayTextBox.AppendText(Environment.NewLine); displayTextBox.AppendText(Environment.NewLine); displayTextBox.AppendText("Quantity \t Item"); displayTextBox.AppendText(Environment.NewLine);

// Displays the order with quantity and the item for (int k = 1; k <= (ordArray.Length / 2); k++) { displayTextBox.AppendText(ordArray[i + 1].ToString() + " \t " + projectDataSet1.Menu.Rows.Find(ordArray[i]).ItemArray[1].ToString()); displayTextBox.AppendText(Environment.NewLine); i = i + 2; } displayTextBox.AppendText(Environment.NewLine);

// Displays the total for the order displayTextBox.AppendText("Total: $");

// Total function is called to calculate the total for the order tot = total(ord); displayTextBox.AppendText(tot.ToString());

// Displays to say if the order is paid for at the table or // it is paid using the Cash/Credit option. if (pay.Equals("1")) { displayTextBox.AppendText("\t" + "Paid at the table using RFID"); } else if (pay.Equals("2")) { displayTextBox.AppendText("\t" + "Cash or Credit Card"); }

// The dotted line shows the end of the order. displayTextBox.AppendText(Environment.NewLine); displayTextBox.AppendText("-------------------"); displayTextBox.AppendText(Environment.NewLine); displayTextBox.AppendText(Environment.NewLine); } }

delegate void ClickSaveCallback(); private void ClickSave() { // This function performs a software click of the rfidSaveButton if (this.rfidSaveButton.InvokeRequired) { ClickSaveCallback d = new ClickSaveCallback(ClickSave); this.Invoke(d); } else { this.rfidSaveButton.PerformClick(); } }

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delegate void ShowRFIDTabCallback(); private void ShowRFIDTab() { // This function shows the rfidTabPage when called for. if (this.rfidTabPage.InvokeRequired) { ShowRFIDTabCallback d = new ShowRFIDTabCallback(ShowRFIDTab); this.Invoke(d); } else { this.rfidTabPage.Show(); } }

private void port_DataReceived(object sender, SerialDataReceivedEventArgs e) { if (!port.IsOpen) { // Open the port if closed. port.Open(); }

// Initializations for the DataReceived function. string inData = port.ReadExisting(); string[] inDataArray = inData.Split(new char[] { '>' }, 4); string outData = ""; string[] coordinates = {"32 30", "330 30", "32 133", "330 133", "32 236", "330 236", "32 339", "330 339"};

try { if (inDataArray[1] != null && inDataArray[1].Length == 12) { // When the RFID tag data is sent, the last two digits // of the RFID tag are truncated // The last two characters of the RFID are the Checksum // characters inDataArray[1] = inDataArray[1].Remove(10); }

// This if statement differentiates between the different kinds // of orders. // 0 - when the system wants the custom menu choices // 1 - when the order is paid for using the RFID gift card // 2 - when the order is intended to be paid for using the cash/credit option if (inDataArray[0].Equals("0")) { outData = ""; string[] customMenu = projectDataSet1.RFID_tags.Rows.Find(inDataArray[1]).ItemArray[2].ToString().Split(new char[] { ',' });

if (projectDataSet1.RFID_tags.Rows.Contains(inDataArray[1])) { string first = projectDataSet1.RFID_tags.Rows.Find(inDataArray[1]).ItemArray[3].ToString(); string last = projectDataSet1.RFID_tags.Rows.Find(inDataArray[1]).ItemArray[4].ToString();

// The outData starts with 4 implying that the RFID is valid

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// and the custom menu choices are sent to the microcontroller outData = "[4>" + first + " " + last + ">" + projectDataSet1.RFID_tags.Rows.Find(inDataArray[1]).ItemArray[2].ToString() + "]"; } else { // The outData starts with 5 implying that the RFID tag // that is read is invalid. outData = "[5]"; }

send(outData); } else if (inDataArray[0].Equals("1")) { double tot = 0; double bal = 0;

tot = total(inDataArray[2]);

outData = "";

if (projectDataSet1.RFID_tags.Rows.Contains(inDataArray[1])) { bal = Convert.ToDouble(projectDataSet1.RFID_tags.Rows.Find(inDataArray[1]).ItemArray[1]) - tot;

if (bal >= 0) { SetBalance(bal.ToString()); }

string first = projectDataSet1.RFID_tags.Rows.Find(inDataArray[1]).ItemArray[3].ToString(); string last = projectDataSet1.RFID_tags.Rows.Find(inDataArray[1]).ItemArray[4].ToString(); if (bal >= 0) { // The outData starts with 1 implying that the RFID tag read // is valid and sufficient funds are available in the account outData = "[1>" + first + " " + last + ">" + bal.ToString() + "]"; DisplayOrder(inDataArray[2], inDataArray[3], "1"); } else { // The outData starts with 2 implying that the RFID tag read // is valid and sufficient funds are not available in the account outData = "[2>" + first + " " + last + ">" + projectDataSet1.RFID_tags.Rows.Find(inDataArray[1]).ItemArray[1].ToString() + "]"; ; } } else { // The outData starts with 5 implying that the RFID tag // that is read is invalid. outData = "[0]"; }

send(outData); } else if (inDataArray[0].Equals("2"))

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{ outData = "";

DisplayOrder(inDataArray[2], inDataArray[3], inDataArray[0]); // The outData starts with 3 indicating that the order has been // placed and it can be paid for using Cash/Credit outData = "[3]"; send(outData); } else if (inDataArray[0].StartsWith("[")) { send("[Srichand]"); } } catch (Exception ex) { // When an Exception is cought, error message is displayed. MessageBox.Show(ex.Message); send("[0]"); } }

private void menuSaveButton_Click(object sender, EventArgs e) { // Saves the menu items and the numbers into the database. menuBindingSource.EndEdit(); menuTableAdapter1.Update(projectDataSet1.Menu); }

private void rfidSaveButton_Click(object sender, EventArgs e) { // Saves the RFID tags and the names into the database. rfidBindingSource.EndEdit(); rfiD_tagsTableAdapter1.Update(projectDataSet1.RFID_tags); }

private void clearButton_Click(object sender, EventArgs e) { // Clears the textbox displayTextBox.Clear(); } }}

F-3 Software for the Touchscreen LCD:

//---------------------------------------------------------------------//---------------------------------------------------------------------// Macros.mac// Macros for the Touch 2 Order system navigation// ECE 477 - Team 13// Last Updated Date: 03/31/2008//---------------------------------------------------------------------//---------------------------------------------------------------------

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//---------------------------------------------------------------------// MACRO #1// Draws a welcome screen for the system. When the screen is touched,// it navigates to macro 2.//---------------------------------------------------------------------#define welcome_screen 1 /*baud 115200xbl ons 0 1zbv 150xi 6 0 0w 1000xs 128 0 0 639 479 // Create an invisible hotspotxm 128 2 // Go to macro 2 when touchedf m16w 1000t "Touch screen to order" 250 450w 1000t "Touch screen to order." 250 450w 1000t "Touch screen to order.." 250 450w 1000t "Touch screen to order..." 250 450w 1000t "Touch screen to order...." 250 450#end

//---------------------------------------------------------------------// MACRO #2// Draws a menu select screen for the system. When button 0 is touched,// it navigates to macro 3 and when button 1 is touched, it navigates// to macro 4.//---------------------------------------------------------------------#define menu_select 2 /*s 0 1zbd 0 66 50 4 "" 0 0 7 8xm 0 2 3bd 1 66 251 4 "" 0 0 9 10xm 1 2 4#end

//---------------------------------------------------------------------// MACRO #3// Displays the options for the full menu.//---------------------------------------------------------------------#define full_menu 3 /*s 0 1zbd 4 66 50 4 "" 0 0 11 12xm 4 3 5bd 5 66 251 4 "" 0 0 13 14

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xm 5 3 6bd 2 0 430 4 "" 0 0 19 20xm 2 3 2#end

//---------------------------------------------------------------------// MACRO #4// Displays the options for the custom menu.//---------------------------------------------------------------------#define custom_menu 4 /*s 0 1zxi 29 0 0bd 3 0 430 4 "" 0 0 19 20xm 3 4 2#end

//---------------------------------------------------------------------// MACRO #5// Displays the options for the Breakfast menu.//---------------------------------------------------------------------#define breakfast_menu 5 /*s 0 1zbd 8 66 50 4 "" 0 0 15 16xm 8 5 7bd 9 66 251 4 "" 0 0 17 18xm 9 5 8bd 6 0 430 4 "" 0 0 19 20xm 6 5 3#end

//---------------------------------------------------------------------// MACRO #6// Displays the options for the Lunch/Dinner menu.//---------------------------------------------------------------------#define lunch_dinner_menu 6 /*s 0 1zbd 12 34 50 4 "" 0 0 21 22xm 12 6 9bd 13 330 50 4 "" 0 0 23 24xm 13 6 10bd 14 34 251 4 "" 0 0 25 26xm 14 6 11bd 15 330 251 4 "" 0 0 27 28 xm 15 6 12bd 7 0 430 4 "" 0 0 19 20xm 7 6 3#end

//---------------------------------------------------------------------// MACRO #7// Displays the options for the Breakfast-Food menu.

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//---------------------------------------------------------------------#define breakfast_food_menu 7 /*s 0 1zbd 20 32 30 20 "" "" 0 0 0 0 30 31bd 21 330 30 20 "" "" 0 0 0 0 32 33bd 22 32 133 20 "" "" 0 0 0 0 34 35bd 23 330 133 20 "" "" 0 0 0 0 36 37bd 24 32 236 20 "" "" 0 0 0 0 38 39bd 25 330 236 20 "" "" 0 0 0 0 40 41bd 26 32 339 20 "" "" 0 0 0 0 42 43bd 10 0 430 4 "" 0 0 19 20xm 10 7 5bd 36 398 430 4 "" 0 0 60 61xm 36 7 13#end

//---------------------------------------------------------------------// MACRO #8// Displays the options for the Breakfast-Beverages menu.//---------------------------------------------------------------------#define breakfast_beverages_menu 8 /*s 0 1zbd 27 32 30 20 "" "" 0 0 0 0 44 45bd 28 330 30 20 "" "" 0 0 0 0 46 47bd 29 32 133 20 "" "" 0 0 0 0 48 49bd 30 330 133 20 "" "" 0 0 0 0 50 51bd 31 32 236 20 "" "" 0 0 0 0 52 53bd 32 330 236 20 "" "" 0 0 0 0 54 55bd 33 32 339 20 "" "" 0 0 0 0 56 57bd 34 330 339 20 "" "" 0 0 0 0 58 59bd 11 0 430 4 "" 0 0 19 20xm 11 8 5bd 37 398 430 4 "" 0 0 60 61xm 37 8 14#end

//---------------------------------------------------------------------// MACRO #9// Displays the Starters/Soups menu for Lunch/Dinner.//---------------------------------------------------------------------#define lunch_starters_menu 9 /*s 0 1zsc 0 0f m24t "Lunch>Starters/Soups Menu:"bd 16 0 430 4 "" 0 0 19 20xm 16 9 6bd 38 398 430 4 "" 0 0 60 61xm 38 9 15#end

//---------------------------------------------------------------------

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// MACRO #10// Displays the Sandwiches menu for Lunch/Dinner.//---------------------------------------------------------------------#define lunch_sandwich_menu 10 /*s 0 1zsc 0 0f m24t "Lunch>Sandwiches Menu:"bd 17 0 430 4 "" 0 0 19 20xm 17 10 6bd 39 398 430 4 "" 0 0 60 61xm 39 10 16#end

//---------------------------------------------------------------------// MACRO #11// Displays the Desserts menu for Lunch/Dinner.//---------------------------------------------------------------------#define lunch_desserts_menu 11 /*s 0 1zsc 0 0f m24t "Lunch>Desserts Menu:"bd 18 0 430 4 "" 0 0 19 20xm 18 11 6bd 40 398 430 4 "" 0 0 60 61xm 40 11 17#end

//---------------------------------------------------------------------// MACRO #12// Displays the Beverages menu for Lunch/Dinner.//---------------------------------------------------------------------#define lunch_beverages_menu 12 /*s 0 1zbd 27 32 30 20 "" "" 0 0 0 0 44 45bd 28 330 30 20 "" "" 0 0 0 0 46 47bd 29 32 133 20 "" "" 0 0 0 0 48 49bd 30 330 133 20 "" "" 0 0 0 0 50 51bd 31 32 236 20 "" "" 0 0 0 0 52 53bd 32 330 236 20 "" "" 0 0 0 0 54 55bd 33 32 339 20 "" "" 0 0 0 0 56 57bd 34 330 339 20 "" "" 0 0 0 0 58 59bd 19 0 430 4 "" 0 0 19 20xm 19 12 6bd 41 398 430 4 "" 0 0 60 61xm 41 12 18#end

//---------------------------------------------------------------------// MACRO #13// Displays a blank screen for the cart items to be displayed.

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//---------------------------------------------------------------------#define display_cart1 13 /*s 0 1zf m14bd 35 0 430 4 "" 0 0 19 20xm 35 13 7bd 52 146 430 4 "" 0 0 64 65xm 52 13 19#end

//---------------------------------------------------------------------// MACRO #14// Displays a blank screen for the cart items to be displayed.//---------------------------------------------------------------------#define display_cart2 14 /*s 0 1zf m14bd 53 0 430 4 "" 0 0 19 20xm 53 14 8bd 52 146 430 4 "" 0 0 64 65xm 52 14 19#end



//---------------------------------------------------------------------

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// MACRO #17// Displays a blank screen for the cart items to be displayed.//---------------------------------------------------------------------#define display_cart5 17 /*s 0 1zf m14bd 57 0 430 4 "" 0 0 19 20xm 57 17 11bd 52 146 430 4 "" 0 0 64 65xm 52 17 19#end


//---------------------------------------------------------------------// MACRO #19// Displays the check-out screen with pay options.//---------------------------------------------------------------------#define checkout_screen 19 /*s 0 1zf m14bd 60 157 75 4 "" 0 0 68 69xm 60 19 21bd 61 157 200 4 "" 0 0 70 71bd 59 0 432 4 "" 0 0 66 67xm 59 19 2#end

//---------------------------------------------------------------------// MACRO #20// Macro for the Sleep mode.//---------------------------------------------------------------------#define sleep_screen 20 /*s 0 1zxbl offxs 129 0 0 639 479xm 129 1#end

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//---------------------------------------------------------------------// MACRO #21// Displays a wait screen for RFID input.//---------------------------------------------------------------------#define wait_screen 21 /*s 0 1zxi 29 0 0bd 62 0 430 4 "" 0 0 19 20xm 62 21 19#end

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Appendix G: FMECA Worksheet

Failure No. Failure Mode Possible Cause Failure Effects Method of Detection

Criticality Remarks

A1 Output = 0V Caused by a failure of any component within functional block or external short

Total Device Failure

Observation Low

A2 Output > 3.3 V Failure of a MAX 1651 Potential damage to XBee Pro, Microcontroller

Observation Low

A3 Output > 5V Failure of MAX 1649 Potential damage to RFID reader

Observation Low

A4 Output out of tolerance

Failure of MAX 1649, 1651 or passive components such as capacitors

Out of spec operating voltage; unpredictable

Observation High

Table G-1 FEMCA Worksheet for Power Supply Circuit

G-1



Criticality Remarks

B1 Data not retrieved from RFID reader

Failure of microcontroller or error in software

Data cannot be sent to the micro from the RFID reader

Observation Low

B2 Blank LCD screen


Data cannot be sent to the LCD screen

Observation Low

B3 No connection with the kitchen server


Communication error with the server

Observation Low

Table G-2 FMECA Worksheet for Microcontroller

G-2



Criticality Remarks

C1 Battery Level not detected correctly

Failure of MAX 1660

Error in detecting the charge level of batteries

Observation Low

C2 Batteries not charging

Failure of MAX 712 and MAX 1660 or dead batteries

Device would not work without external power supply

Observation Low

C3 Batteries excessively charged

Failure of MAX 712 or MAX 1660

Batteries may leak or explode

Observation High Sometimes may cause damage to other components

Table G-3 FMECA Worksheet for Battery Circuit

G-3

ee 477 final report - purdue university · web viewappendix g: fmeca worksheet ? abstract as a part...

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