WaitLess Bus Tracking Display Matthew Brooks Christopher Chidi Daniel Nadeau Josh Mauldin Georgia Institute of Technology ECE 4007 Senior Design Final Project Presentation April 24 th , 2009
Jan 04, 2016
WaitLess Bus TrackingDisplay
Matthew BrooksChristopher Chidi
Daniel NadeauJosh Mauldin
Georgia Institute of Technology ECE 4007 Senior Design
Final Project PresentationApril 24th, 2009
Project Overview What: A display showing GPS locations of Georgia Tech
campus buses using LEDs arranged along a map placed at campus bus stops.
Why: 96% of surveyed students are dissatisfied with current text based bus prediction systems which are limited to only a few bus stops.
Who: Assists campus pedestrians in deciding whether to wait for the bus or just walk.
Cost: Estimated prototype development cost of $6700. Per unit cost production will be ~ $600.
Design Objectives Low Power
Solar panel with battery Low power micro-processor
Internet Access Wi-Fi module Use existing GPS data available via
NextBus.com (XML feed)
Self-Sustaining/Easy to Deploy No wires/low maintenance No energy cost Weather proof case
Low Cost Per unit cost ~ $600
Design Overview12Và 5V
Regulator
5V
I2C
5V
5Và 3VRegulator
12V BatterySolar Charger
Processor
LED Display
WiFi Module
5Và 3VVoltage Divider
3Và 5VLevel Shifter
Serial
Obstacles and ModificationsObstacles Solutions
Found that LED leads were not as specified on spec sheet, hence flawing PCB design
Soldered jumper wires on the PCB to correct the layout error
RN-111b WiFly module did not support HTTP and therefore could not poll NextBus server
Implemented the Nano WiReach module which has support for HTTP and XML data
The serial pin header on the Nano WiReach module was too small to solder wires to
Ordered the Molex pin header connector mate and soldered the pins to a breakout board
Obstacles and ModificationsObstacles Solutions
Nano WiReach module failed for unknown reasons
Had on hand a spare module, Secure Socket iWiFi, which operates similar to WiReach
ATMega168 processor lacked sufficient onboard memory (16KB) and RAM (1KB)
Upgraded to the ATMega328 which has 32KB of memory and 2KB of RAM
Processor uses 5V TTL for serial communication whereas the Wi-Fi module uses 3V, hence could not communicate via serial link
Implemented a 5V – 3V voltage divider from the processor to module, and a 3V – 5V level shifter from module back to the processor
PCB Board Design Verification PCB board testing and verification
− Corrected LED lead assignments − Performed diagnostics testing by lighting all LEDs using I2C
commands from the Arduino processor
Troubleshooting Visual Display and Aesthetics
Tested LED visibility after assembly of display box− Decided to use heat shrink wrap to funnel LED illumination
Serial to Wi-Fi Module Configuration Wi-Fi module network connectivity and XML data collecting
− Utilized RealTerm Serial / Telnet software for module configuration and AT+i serial code debugging
Arduino Processor Programming / Debugging
Microprocessor programming and debugging− Utilized Arduino C
programming platform to code and debug data communications and parsing algorithms.
Power Supply Testing Tested solar panel power supply and battery supply
− Found that the solar panel provides ~450 mA of current in daylight conditions
− Original battery supply was faulty, obtained a new battery
Acceptance Testing Compared WaitLess display with the NextBus Live Map Performed final testing with system as standalone
− Assembled final product with battery and solar panel attached and positioned system at an actual bus stop
Results Product is capable of tracking all buses on all four
routes of the Georgia Tech transportation service Current draw of the device at peak operating
conditions is ~200 mA which is well below the 450 mA provided by solar panel
Connecting to GTwireless requires external device authentication through PC− New WPA security features of GT LAWN network
will ease module connectivity Wi-Fi module sometimes becomes unresponsive
after 5-10 minutes of operation− Needs a firmware update
Project Demonstration Requirements
Display the tracking of all buses on at least two routes of the campus bus service
Demonstrate the sustainability of the product i.e. solar powered
Demonstrate low current draw / power Demonstrate standalone operation running solely
on battery and solar power Exhibit wireless connectivity and weather resistance
Market / Cost AnalysisComponent
Labor Hours Labor Cost Equip Cost Total Cost
Arduino Duelmilanove/ ATmega328/V
150 $5,250.00 $34.95 $5284.95
I2C LED Controllers 2 $70.00 $16.00 $86.00
Red, Green, Blue LEDs 10 $350.00 $33.99 $383.99
Serial to Wi-Fi Module 1 $35.00 $62.90 $97.90
Solar Panel 1 $35.00 $49.95 $84.95
Battery 1 $35 $18.21 $53.21
Switching Voltage Regulator 2 $70.00 $22.00 $92.00
Custom PCB 10 $350.00 $100.00 $450.00
External Weather-Proof case 3 $105.00 $50.00 $155.00
TOTAL LABOR 180 $6,300
TOTAL PARTS $388.00
PROJECT TOTAL $6,688.00
Market / Cost AnalysisTotal Project Cost: $6,688.00
Physical Value of Product:
$388.00
# of Units Capable of being sold:
42 for each bus stop on the GT campus
Estimated Market Value of Product to
Break Even:$600.00
Future Enhancements and Modifications Reduce the depth of the display box
− Implement a smaller, more efficient battery− Solder all electronic components to one PCB
design− Investigate surface mount LED technology
Place the vinyl map decal inside of transparent casing to protect it
Implement WPA security login for easier module connectivity
Expand the design to be used for other transportation services
Add an LED array panel below the map display to output text-based arrival time estimations for each stop
Questions?