kit
https://www.raspberrypi.com.tw/13504/pi-follower-car-starter-kit/
slides
https://www.slideshare.net/raspberrypi-tw/raspberry-pi-65881533
comments
https://www.facebook.com/RaspberryPiTaiwan/videos/1041175076003103/
new commit
https://github.com/raspberrypi-tw/pi-follower-car
1. delete the condition of radius to make camera can see small object
2. use dc motor by default, pwm motor is for exercise
camera
https://www.raspberrypi.org/documentation/usage/camera/raspicam/raspistill.md
https://www.raspberrypi.org/documentation/usage/camera/python/README.md
opencv