Thomas Schoch, of Essen, Germany, built a neat robot with a Raspberry Pi and a Zumo Chassis Kit. The PiBot-B is controlled by a custom iPhone app that communicates over WiFi to the Raspberry Pi, which is running lighttpd and PHP. A Python program uses the WiringPi library to send signals to an L293D motor driver that drives the two 100:1 Micro Metal Gearmotors in the Zumo chassis. The iPhone app displays video from the attached Logitech C300 webcam, and the robot has an integrated 8×8 LED matrix from Adafruit that indicates its state. In the future, Thomas plans to add sensors for obstacle detection and make the robot autonomous. We were impressed by several things:
- PiBot-B is very tidy, thanks in part to the USB cables that were shortened and modified using liquid rubber.
- The Raspberry Pi has only one PWM output so Thomas used two OR gates to select whether the left motor, right motor, or both motors receive the PWM signal.
- The write-up has some great photos and informative diagrams.
The PiBot-B page is written in German, but it has a link at the top to translate it into English using Google Translate.