In a sound-equipped N scale locomotive, the speakers tend to average ... demo of the Rolling Thunder system on YouTube and ...

Removing the turntable and it’s requisite parts made plenty of room for the N-scale railroad (that’s really small stuff!). An Arduino with a motor shield drives the train around the loop.

He explains it in his own words in the demo video. The sensor was small enough for an N-gauge train, which translates to 1:148 scale or about 9mm from rail to rail. His idea was to build a tiny ...