report on transformer wheelchair

8/2/2019 Report on Transformer Wheelchair

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PROJECT REPORT

on

TRANSFORMER WHEELCHAIR

Submitted By :-

PIYUSH GUPTA


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ABSTRACT

Embedded systems are found in variety of common electronic devices like (a)

consumer electronics cell phones, pagers, digital cameras, camcorders, videocassette

recorders, portable video games, calculators and personal digital assistants; (b) home

appliances microwave ovens, answering machines, home security, washing machines

and lighting systems; (c) office automation fax machines, copiers printers and

scanners; (d) business equipment; (e) automobiles transmission control, anti lock

brakes etc.

This report is an attempt to throw some light on over of embedded systems,

classification and description of various application areas of embedded system.


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Table of Contents

1. Introduction to Embedded Systems

2. Microcontrollers Trend in the Embedded Systems

3. Application of Embedded Systems in sphere of life

4. Variants in Atmel 8051 Microcontroller

5. Introduction to the project

6. Circuit Diagram

7. PCB Layout

8. Program in Assembly

9. Conclusion & Future work

10. Bibliography


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Introduction to Embedded Systems

In the daily life we use lots of electronic devices like Calculators, Computers,

Automatic Washing Machines, and Mobile phones etc. The common thing in all these

devices is that they all contain Microprocessor. So they all are Microprocessor based

system.

Actually Microprocessor based systems are divided into two categories:

1. Reprogrammable Systems

2. Embedded Systems

Reprogrammable Systems

These are the general purpose systems. We can run programs of different type of

language programs like C, C++, Java etc. Even we can listen the music, watching the

movies etc. That is, these systems can be reprogrammed from the users side of view

and they are general purpose type. Examples of these systems are Personal Computer,

Workstations etc.

Embedded systems

These are not general purpose systems but these systems can specially designed for

specific applications. The examples of embedded systems are Robots, Calculators,

Metro Rails without drivers etc. In such a way we can say that, Embedded Systems

are microprocessor based electronics systems which are designed for the specific

task only.


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Micro Controllers Trend in the Embedded Systems

Application of embedded systems in sphere of life

Consumer electronics

Telecommunication

Automobile

Medical instrumentation

Industrial control equipment

Defense

Communication satellite

Data communication

Internet appliances

0.0%

20.0%

40.0%

60.0%

80.0%

100.0%

4-bit 8-bit 16-bit 32-bit 64-bit Special

0.0%

20.0%

40.0%

60.0%

80.0%

100.0%

4-bit 8-bit 16-bit 32-bit 64-bit Special


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8051 Microcontroller

AT89C51:

The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4Kbytes

of Flash programmable and erasable read only memory (PEROM). The device is

manufactured using Atmels high-density nonvolatile memory technology and iscompatible

with the industry-standard MCS-51 instruction set and pin out. The on-chip Flash allows the

program memory to be reprogrammed in-system or by a conventionalNon-volatile memory

programmer. By combining a versatile 8-bit CPU with Flashon a monolithic chip, the Atmel

AT89C51 is a powerful microcomputer which providesa highly-flexible and cost-effectivesolution to many embedded control applications.

The AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of

RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a

full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is

designed with static logic for operation down to zero frequency and supports two software

selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM,

timer/counters, serial port and interrupt system to continue functioning. The Power-downMode saves the RAM contents but freezes the oscillator disabling all other chip functions

until the next hardware reset.


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Pin Configuration:

Pin Description:

VCC: Supply voltage.

GND: Ground.


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Port 0:

Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink

eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high

impedance inputs. Port 0 may also be configured to be the multiplexed low order

Address /data bus during accesses to external program and data memory. In this mode

P0 has internal pull ups. Port 0 also receives the code bytes during Flash programming,

and outputs the code bytes during program verification. External pull ups are required

during program verification.

Port 1:

Port 1 is an 8-bit bi-directional I/O port with internal pull-ups. The Port 1 output buffers

can sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled high

by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are

externally being pulled low will source current (IIL) because of the internal pull-ups.

Port 1 also receives the low-order address bytes during Flash programming and

verification.


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Port 2:


can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high

by the internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are

externally being pulled low will source current (IIL) because of the internal pull-ups.

Port 2 emits the high-order address byte during fetches from external program memory

and during accesses to external data memory that use 16-bit addresses (MOVX @

DPTR). In this application, it uses strong internal pull-ups when emitting 1s. During

accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits

the contents of the P2 Special Function Register. Port 2 also receives the high-orderaddress bits and some control signals during Flash programming and verification.

Port 3:


can sink/source four TTL inputs. When 1s are written to Port 3 pins they are pulled highby the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are

externally being pulled low will source current (IIL) because of the pull-ups. Port 3 also

serves the functions of various special features of the AT89C51 as listed below: Port 3

also receives some control signals for Flash programming and verification.


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ALE/PROG:

Address Latch Enable output pulse for latching the low byte of the address during

accesses to external memory. This pin is also the program pulse input (PROG) during

Flash programming. In normal operation ALE is emitted at a constant rate of 1/6 the

oscillator frequency, and may be used for external timing or clocking purposes. Note,

however, that one ALE

Pulse is skipped during each access to external Data Memory. If desired, ALE operation

can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is activeonly during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high.

Setting the ALE-disable bit has no effect if the microcontroller is in external execution

mode.


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RESET:

Reset input. A high on this pin for two machine cycles while the oscillator is running

resets the device.

PSEN:

Program Store Enable is the read strobe to external program memory. When the

AT89C51 is executing code from external program memory, PSEN is activated twice

each machine cycle, except that two PSEN activations are skipped during each access

to external data memory.

EA/VPP:

External Access Enable. EA must be strapped to GND in order to enable the device to

fetch code from external program memory locations starting at 0000H up to FFFFH.

Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset.

EA should be strapped to VCC for internal program executions. This pin also receives

the 12-volt programming enable voltage (VPP) during Flash programming, for parts

that require 12-volt VPP.


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XTAL1:

Input to the inverting oscillator amplifier and input to the internal clock operating

circuit.

XTAL2:

Output from the inverting oscillator amplifier.


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Block Diagram:


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INTRODUCTION TO THE PROJECT

The project presents the design and construction of a prototype of an electronic

wheelchair for people (children and adult) with motor disability. The prototype of the

wheelchair was built using a small computer embedded in a chip known as a

microcontroller, chosen for its low cost, in addition to its versatility and ability to

handle signals and its performance in mathematical operations and communication with

other electronic devices.

In this project

In this project we try to give the prototype for Electronic Wheelchair. We are using

microcontroller 89c51 as CPU. The motion of the wheelchair is controlled by two dc

motor. Using a remote control, this prototype can be manipulated to perform basic

movements like forward, backward, turn left or right and stop.

Project Features

Suitcase Portable

Low power consumption

Light weight

Durable

Mecha-tronic assembly

Mecha-tronic assembly:

It is the combination Mechanical and Electronic modules.


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Electronic Module:

Components Used

Atmel 89C51 microcontroller

IC- L293D

Voltage regulator IC- LM7805

Voltage regulator IC- LM7812

2 pin connector- 3

8 pin connector- 2

12 MHz crystal oscillator

Ceramic capacitor(30-33pf)- 2

Micro switch

Resistance 470 ohm

Semiconductor LED

Design and Development of the Prototype

Having identified the components which were used to build the prototype of the chair, a

design was made, resulting in a circuit that was divided into four main modules, these

are:

The power module.

The wired remote control module.

The module for the electronic logic control.

The actuators module.


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Power module:

Considering that this is a low energy scale model, we decided to operate on batteries;

specifically, squared, 14 volt batteries were used, to which a voltage regulator known as

LM7805 and LM7812 was applied to reduce battery voltage. In this module, a power

indicator light for the circuit and a capacitor for energy were added, to make the power

stable and independent from the consumption required by the other modules of the

circuit, which may cause voltage variations that affect other parts.

Wired remote control module:

For this module we decided to use four buttons to indicate the direction of movement of

the chair (forward, backward, left and right).

Module for the electronic logic control:

This module is the main part of the circuit, where the main electronic components for

the operation of the microcontroller are located. Here, programmed routines are stored

to control all the actions of the chair. For the working frequency, a 12MHz oscillator

was connected, considering an appropriate speed for the tasks scheduled.


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Actuators Module:

This module controls the motors in accordance with electrical signals received by the

microcontroller. It uses a chip to interface signals from the microcontroller and provide

the appropriate energy consumption required by the engines. Without it the

microcontroller would be unable to provide the minimum energy for their operation.

L293D IC was implemented, which is a dc motor controller. This IC can connect two

motors, which is appropriate to the prototype of a wheelchair.


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CIRCUIT DIAGRAM

Circuit of Logic Control:


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Circuit for Keypad :


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PCB Layout:


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Program in Assembly:

/*PROGRAM FOR PROTOTYPE ELECTRONIC WHEELCHAIR */

$MOD51

ORG00h

Back: MOV P0,#00000000b

MOV P2,#00000000b

MOV A,P0

XRL A,#04h

JZ Forward

MOV A,P0

XRL A,#02h

JZ Rev

MOV A,P0

XRL A,#01h

JZ Left

MOV A,P0

XRL A,#08h

JZ Right

SJMP Back

Forward:

MOV P2,#10010000b

SJMP Back

Rev:

MOV P2,#01100000b

SJMP Back

Left:

MOV P2,#00010000b

SJMP Back

Right:


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MOV P2,#10000000b

SJMP Back

RET

END


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Conclusions and Future Work

This project presents the design and construction of aprototype of an electronic

wheelchair motor drive for people with disabilities using electronic and computer

technologies based particularly on the use ofmicrocontrollers aimed at allowing users a

greater degreeof independence, which will improve their quality of life.This project is

intended to serve as a basis for implementing further functions such as timely and

accurate detection of obstacles to prevent the chairs colliding with walls or other

objects, as well as prevent the chair from fallingdown stairs or curbs. Another project

that can be derived from this is handling it wirelessly via Bluetooth communication

using an electronic device (cell phone orPDA), the wireless controller will perform the

samemovements as the manual control.


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BIBILOGRAPHY

Books:

Title: The 8051 Microcontroller and Embedded System.

Author: Muhammad Ali Mazidi & Janice Gillispie Mazidi.

Publication: Pearson Education.

Title: The 8051 Microcontroller

Author: J. H. Ayala

Publication: Eastern Economy Edition

Websites:

SOFTWARE:www.keil.com

Reference: www.efymag.com

Datasheets: www.datasheetarchive.com
http://www.keil.com/http://www.keil.com/http://www.efymag.com/http://www.datasheetarchive.com/http://www.keil.com/http://www.efymag.com/http://www.datasheetarchive.com/

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