Wooden Controller Lets the Kiddos Play Engineer

James Clark’s two kids love their LEGO DUPLO train, particularly his youngest, who struggles to communicate with words. To help her play with the train independently of adults, or even tablets, he constructed a remote with a simple throttle lever and four buttons.

The device is built out of CNC-cut wood, and externally finished in a style that fits in with the rest of the train. Its four buttons are colored a cheery yellow, white, blue, and red, and have icons to describe their functions. Button options include pausing the train, light activation, and two noises. The lever handle is made from stacked together plywood. Its mechanism controls a potentiometer to make the train go forward and in reverse at two speeds, or stop in the center.

The train system normally features a Bluetooth phone/tablet app for operation, so hijacking this wireless interface was the natural starting point for hacking. To accomplish that, he chose to use the Espruino platform for this implementation, running on an MBT42Q chip which includes Bluetooth functionality.

Code for the project, along with cutting templates, are available in Clark's project post. If you want to control a DUPLO train, or perhaps even something similar, you won’t have to start from scratch!