Model trains have been a staple of DIY hobbiysts for generations, and while wireless control options can be purchased, KushagraK7’s hack lets you use your phone instead.

The setup consists of an Arduino Uno, along with a motor driver shield to vary the trains’s peed and direction, as well as flip turnouts to allow for different sections of track to be used.

The system employs a novel interface system, where an off-the-shelf Bluetooth receiver passes DTMF (telephone dial tones) to a decoder board, which then sends this decoded data on to the Arduino. While some might opt for an HC-05 Bluetooth module or similar, this enables control with a standard tone generator app, and the phone could even be physically connected via a stereo cable if convenient.