1. Charlotte Weaver, Bill Mowrey & Huai-Ti Lin
Janelia PixyRace 2016
The algorithms and code for the PixyRacer
PixyRace Workshop 4 [May 31st 2016]:
Charlotte Weaver, Bill Mowrey & Huai-Ti Lin
Acknowledgement: IDF: Cameron Loper

2. In this workshop Specifications and wiring of the robot
Algorithms in the example robot code
Basic tuning of PixyCam (using PixyMon)
Python implementation of the algorithms
How to edit and run the example code

3. Pixy Racer wiring diagram
PixyCam
Raspberry Pi3
Software modules:
Pixy function
Camera pan control
Drive function
Guidance algorithms
Left motor
Pan servo
Right motor
Motor driver
Toggle switch
12v regulator
Hardware specs:
5v regulator 9v 5v
~9v battery pack
12v
Signal

4. Pixy wiring and block output
block size
signature #
blocks[0]
blocks[1]
blocks[2]
blocks[3]
blocks[4]
blocks[5]
blocks[6]
blocks[…]
Objects are ordered by size first and then signature number
Servo plug with yellow line on top
Bend USB cable here and loop around the standoff

5. Drive function: power distribution
TotalDrive
Power available
(480)
How much power?
Throttle (0~1)
How much for steering?
diffGain (0~1)
diffDrive
synDrive
How to turn and how hard to drive?
bias (-1~1)
advance (-1~1) =
Left Motor Drive +
LeftDiff +
LeftSyn =
Right Motor Drive -
RightDiff +
RightSyn =
bias
PanError/(half Pixy image width) * h_pgain

6. Guidance algorithms 1. Object tracking 2. Line following Object size
Distance
synDrive
Target vector
Object angle
Orientation
diffDrive
Heading vector
synDrive
2. Line following
Object angle
Orientation
diffDrive

7. Tuning PixyCam (PixyMon)

8. Head control code

9. Drive function code

10. Guidance code

11. Editing your code on Pi

12. SSH setup & run