Data Bus

This is an overview of the 2014 version of Data Bus, 3rd place winner of the 2012 Sparkfun AVC.

Data Bus Specs

Total Cost	$650
Chassis	1/10th 2wd ECX Circuit RC vehicle with suspension tuned for improved cornering
Body	Parma “Skool Bus” custom painted by author
Motor	Tacon 3000Kv 2848-540XL brushless
Battery	Gens Ace 2S, 5000mAH 40C LiPo
Weight	Approximately 5 lbs
MCU	mbed 96MHz ARM Cortex M3
Language	C/C++
Power Supply	Pololu 3.5A, 5V Step Up Regulator
GPS	3DR uBlox LEA-6H set a 4Hz update rate
Gyro	Pololu MinIMU-9 with an STM L3G4200D 3-axis gyro
Wheel Encoders	32 ticks per revolution; QRE1113 IR sensor from Sparkfun,  custom Schmitt trigger interface
Estimation	Heading via gyro in near real time unbiased using 2-state Kalman filter using GPS heading and time-lagged gyro heading inputs. Distance via wheel encoders.
GCS	Custom Ground Control Station written in Java Swing

Changes Since 2012

• Converted to offline compile for mbed SDK. [source]
• Improved user configuration
• Attempted to implement FreeRTOS. Fail.
• Replaced previous GPS with 3DR uBlox LEA6-H.
• Converted path following to Pure Pursuit algorithm.
• Custom Ground Control Station (GCS) [source]
• Telemetry broadcast to GCS via Xbee Pro.
• Converted to XT60 connectors and new 2S LiPo.
• New RoverBaseboard to support mbed and LPCXpresso.
• New RoverMux multiplexer board.

Still To Do

• Robot does not stop upon reaching last waypoint;
• Unclear whether robot is accurately navigating to final waypoint;
• Test runs to verify precision, accuracy;
• Attempt to improve performance in speed, precision, and accuracy.

More Technical Details

For additional technical detail about the robot, click here.

Resources

diyrovers discussion group
http://is.gd/diyrovers

ArduRover user's group at
http://diydrones.com/group/ardurover-user-group

WheelEncoderGenerator program:
http://code.google.com/p/wheel-encoder-generator/

Fundamentals of Kalman Filtering: A Practical Approach, Paul Zarchan,
ISBN: 1563474557

Vendors

ECX, www.ecxrc.com, (800) 338-4639
Sparkfun Electronics, www.sparkfun.com, (303) 284-0979 (No phone orders)
Pololu, www.pololu.com, (877) 776-5658
HobbyPartz, hobbypartz.com, (626) 968-9860
A Main Hobbies, www.amainhobbies.com, (800) 705-2215
Acroname Robotics, www.acroname.com, (720) 564-0373

2012 AVC Results

Air:

1st Place: Team Overhead, 36.62 seconds
2nd Place: Team Robota, 44.50 seconds
3rd Place: Lost in Air-Space, 54 seconds

Ground:

1st Place: Team 0x27, 2.08 seconds (32.08 raw)
2nd Place: Team Minuteman, 9.46 seconds (39.46 raw)
3rd Place: Team Databus, 37.16 seconds (37.16 raw)

Other:

Crowd pleaser: Die!Wheel!
Rookie Award: Short Circuit
Best Dressed: Kegbot
Water Hazard: Viator
Engineer's choice: Namniart
Kill Switch: Snobbotics
Purple Heart: Snobbotics, Team Databus

Sparkfun AVC

The 2012 Recap: http://www.sparkfun.com/news/894