Carambola on Wheels

I lately took my Carambola an put it on a DFRobot 4WD mobile platform. Then, I connected a Logitech C270 HD web-cam which connects to the Carambolas USB port. By configuring „mjpeg_streamer“ like described in the Carambola Wiki, streaming live video over the Carambolas WiFi then is just a peace of cake :-).

For operating the 4 DC motors, I used the DFRobot 2A Dual Motor Controller. This the pins for controlling the motor movements are connected to the GPIOs on the Carambolas expansion header. For setting/clearing the GPIOs, I used the Kernels "sys" file system like described here.

To remote control the robot I wrote a little client-/server software in Python. The server runs on the Carambola and listens for commands on a UDP port. The commands send over the air are just "pickled" Python hash maps. On the client side, there is a Python script with a simple ncurses interface waiting for presses on the arrow keys. The (undocumented) Python sources are available at github.

Carambot ncurses remote control

Carambot ncurses remote control

Logitech web-cam

Logitech web-cam

DFRobot with Carambola and Logi web-cam

DFRobot with Carambola and Logi web-cam

DFRobot motor controller

DFRobot motor controller

For watching the video stream (640x480@15fps), I got best results with chromium-browser (VLC was lacking behind, and also did Firefox). The above video shows how the live stream from the Carambola looks like.

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