ece 477 design review team 16
DESCRIPTION
ECE 477 Design Review Team 16. Neil Kumar, Scott Stack, Jon Roose, John Hubberts. Project Overview. Home security robot 2 Modes of operation Manual Control Go to a website and drive the robot Live Color or Infrared video feeds Autonomous sentry mode - PowerPoint PPT PresentationTRANSCRIPT
ECE 477 Design Review Team 16
Neil Kumar, Scott Stack, Jon Roose, John Hubberts
PROJECT OVERVIEW• Home security robot• 2 Modes of operation
• Manual Control• Go to a website and drive the robot• Live Color or Infrared video feeds
• Autonomous sentry mode• Patrol the house via a 2D floor mapping algorithm• Detection of human skeleton• Alerts the user if an intruder is detected
PROJECT SPECIFIC SUCCESS CRITERIA (PSSC)1. An ability to control the speed and direction of a
robot2. An ability to automatically detect and avoid
obstacles3. An ability to capture and transmit live video from a
Kinect to a web server4. An ability to control the movement of the robot
through a web interface5. An ability to identify and respond to the detection
of a human
FUNCTIONAL BLOCK DIAGRAM
MAJOR COMPONENTS - MICRO REQUIREMENTS
• 5 A/D channels for IR sensors
• 2 PWM channels for motors
• 1 UART interface for communication with ATOM board through RS232
• 1 I2C module for communication with fuel gauge on battery PCB
• 4 GPIO channels for H-bridges
• 2 Input Capture channels for tachometers
MAJOR COMPONENTS - MICRO SELECTIONPIC24FJ128GA006
• 16 A/D channels
• 5 PWM channels
• 2 UART modules
• 2 I2C interfaces
• 8MHz internal oscillator
• 64 pin TQFP package
• Operating Voltage 2.0V-3.6V
MAJOR COMPONENTS - MOTHERBOARD REQUIREMENTS
• Three USB portso XBox Kinecto Flash Drive containing OSo WiFi adaptor
• RS-232 Module for communication with microcontroller
• High speed, preferably dual-core processor (for real time encoding of Kinect camera data)
• Relatively low power consumption for the sake of battery life (<40W preferred)
MAJOR COMPONENTS - MOTHERBOARDIntel® Desktop Board DN2800MT
• Eight USB 2.0 Ports (4 External, 4 Internal)
• Two RS232 Serial Connection Port
• Intel® Atom Processor N2800• 1M Cache, 1.86GHz Dual Core
• Fanless cooling system
• Minimum Power Consumption 24.5W
PACKAGING CONSTRAINTS
• Needs to be able to navigate indoor terrain
• Needs to be able to support 10lbs of electronic equipment
• Needs to be short enough to turn around in relatively narrow hallways (~5ft wide)
• Needs to be built in a way that prevents Kinect from 'seeing' parts of the chassis
RENDERING OF PACKAGE DESIGN (FRONT)
RENDERING OF PACKAGE DESIGN (REAR)
Schematic constraints
• Control direction and speed of 2 motors (PWM/GPIO)
• Read in data from 5 IR sensors (ADC)• Read in fuel level from fuel gauge (i2c)• communicate control/sensor data to/from
Atom (UART - RS232)• requires 4 regulated voltage levels (12V,
7.2V, 5V, 3.3V).
Design Considerations
• We will not have a re-charging IC integrated into our design. Thus, the battery will have to be removed and charged with a commercially available charger.
• The Fuel Gauge we are using is required to be attached to the battery during charging and discharging in order to maintain accuracy.
• As a result of both of these factors we will be using 2 separate PCB's
• Use Decoupling capacitors reduce power noise
• Try to separate modules physically from each other on microcontroller.
Microcontroller Schematic
• 5 ADC Sensors• RS232 level converter and COM port• 12V, 7.2V, 5V regulators• H-Bridge and motor control circuit• Input Capture (tachometer)• i2c circuit• Debugging Circuit
ADC
• 5 pins from microcontroller padded to headers for sensors.
• IR sensors return 10-bit value to microcontroller
• Use analog reference voltage of 5V• Pins Used: AN9,AN5, AN4, AN3, AN2
RS232 Level converter and COM port
• Microcontroller has to send sensor data and receive control data from the Intel Atom
• Micro will accomplish this using its UART module via RS232 (pins: U1RX, U1TX)
• These signals must be converted from 3.3V to 5V before passing through a RS232 (MAX233) Level converter and to a COM port.
H-Bridge Motor Control Circuit
• Two 16-bit PWM pins (OC2, OC3) used to control speed of two motors
• 4 GPIO pins (RE4, RE3, RE2, RE1) used to control direction of motors through the H-Bridge
• All six signals are converted from 3.3V to 5V logic using the TXB0108, a bi-directional digital logic converter.
• The motors require 7.2 V input at up to 4 Amps, H-Bridge (L298) draws regulated 7.2V to power motors.
• requires inductive kickback diodes that can handle up to 1000V ~ 2A (max)
Input Capture
• Tachometer provides 90 pulses for every rotation of motor
• calculates pulses based on integrated IR sensor and light.
• Used to measure time between pulses from the tachometer to calculate speed and distance traveled.
• Uses pins IC3 and IC4
i2c Circuit
• We will only have one device using the i2c module, the fuel gauge IC (BQ34Z100).
• Since the micro and the fuel gauge are on separate boards the SDA/SCL lines will be padded out to headers on both boards and connected via a two wire cable.
Debugging Circuit
• Reset Pushbutton• Debugging LED• RJ11 In-Circuit Debugger connection : pins
PGC1 and PGD1 • All microcontroller pins are padded out to
headers
Battery Schematic
• 3.3V regulator • Fuel Gauge IC
o measures the current from the battery using a .012 ohm current sensing resistor, the resistor value that we chose is based on equations from the datasheet.
• Both boards will be connected by two cables:o two wire barrel connector providing unregulated
voltage from batteryo 4 wire bus ( .1" header ) providing the regulated
3.3V, and the two i2c signals.
Overall PCB Design Considerations
• Two separate PCBso Battery PCB - 3.3 volt regulator and fuel gaugeo Main PCB - microcontroller, power supplies, motor
driver, and sensors
• Power Supplies - 3.3, 5, 7.2, 12 volt supplieso All switching regulators that require careful layouto Wide traces to accommodate large amounts of
current
• Isolation of high current circuits from digital logico Microcontroller and analog sensors far from 12/7.2
volt power supplies and H-bridge circuit.
Overall PCB Design Considerations (cont.)• Pad out unused pins on microcontroller• Board space to accommodate external
connectorso Female RS232 - communication with Atomo 2 Barrel - Unregulated battery power and 12 volt output to
Kinect and Atom boardo Five 3 pin headers to IR sensors o Standard 0.1 inch headers for communication with other PCB,
optical encoders, motors, and unused microcontroller pinso RJ-11 connector for programming/debugging the PIC
microcontroller
• Main board smaller than 10"x10"
Overall PCB Design Considerations(cont.)
• Battery PCB smaller than 3.5"x3.5"• No acute angles in traces or pours• No right angles in data traces• Trace widths
o At least 12 mil traces with 12 mil spacing for data lines
o Use 100 mil traces for power where possible.o Copper pours where there is space to reduce noise
produced by a circuit
• Locate decoupling capacitors as close to ICs as possible
Power Supplies - 12 Volt Supply
• LM25085 switching regulatoro Most external components of all sources
• Locate components as close to IC pins as possible.
• Minimize the length of key current loops• Use wide traces and copper pours
Power Supplies - 7.2 Volt Supply
• TPS5450-Q1 switching regulator• Locate components as close to IC pins as
possible. • Use wide traces and copper pours• Thermal pad under IC for heat dissipation
o Vias on the thermal pad to aid in heat dissipation
Power Suplies - 5 Volt / 3.3 Volt
• TPS62160 adjustable linear switching regulatoro resistor voltage divider determines output voltage
• Suggested layout in the datasheet
Microcontroller Layout
• Decoupling Capacitors on opposite side of microcontroller.
• Two row standard 0.1" spaced headers to pad out all pinso Debuggingo Unused pins
• RJ-11 header for PIC ICD 3 programming and debugging
• Reset button• Debugging LED
Battery PCB Layout
• Plenty of extra spaceo Used very wide traces and copper pours for high
current paths
• Ground plane
Software Design/Development Status
• Webservero Video Streaming - 90%o C&C Webpage - 0%
• Atom Boardo Kinect Depth Sensing - 60%o Point to Point Navigation - 20%o Map Building & Location Tracking - 10%
• Micro controllero Sensor Input - 80%o Motor Control - 0%o Tachometers - 0%o Fuel Gauge Communication - 0%
Software Design/Development Status
Software Design/Development Status
Timeline for Completion
Questions?