Hacking a London Underground Door Button for Home Use

According to home-hacker “banjowise,” the London Transport Museum shop is currently selling decommissioned door buttons from the Jubilee line. These come in an “as-is” condition, with dirt and other grime built up over the years — a testament to how well designed this type of interface has to be. So, with a little cleanup, banjowise was able to turn a grimy subway button into a beautiful home control switch that interfaces with Philips Hue lights.

A large part of this project involved taking the device apart and cleaning it, including disassembly of its two circuit boards. After a thorough soak and scrub process, only one of the original PCBs was replaced — the one directly behind the button — allowing it to shine like the original model while interfacing with a new ESP32 module. The original lighting module takes 9V power and is now operated by a 9V battery and MOSFET.

Code for the setup can be found here, and although there’s only one button, banjowise was able to eke out quite a bit of functionality. A single press turns the lights on/off, double press cycles through scenes, and a long press dims then brightens. There’s even a “disco mode” that integrates with a Sonos system, playing upbeat music and flashing the lights different colors, seen in the video below.