This project comes from Playful Technology, which is a YouTube channel that focuses heavily on the tech behind escape room puzzles. For instance, we recently covered their Secret Knock escape room puzzle build. This project was also inspired by escape room puzzles, specifically a puzzle that requires players to hold hands in order to proceed. That seemed fitting for Valentine’s Day, so Playful Technology made this video to explain how it works.
This runs on an Arduino Nano, but just about any Arduino should work. It works thanks to your body’s natural conductivity. Essentially, it pushes a small, extremely low-current voltage through your body, to your partner’s body, and back to the Arduino. If you’re holding hands, the circuit is closed and the Arduino can recognize that as a simple digital input.
Once it detects that you’re holding hands, it uses a DFPlayer Mini MP3 module to play a song — “I Want to Hold Your Hand”in this case. Audio files can be stored on an SD card, so you can choose whatever music you like. That module can be used with a simple speaker, but Playful Technology took advantage of the stereo output to feed a small amplifier and really pump up the volume. If you’re excited about holding hands with a special someone today, or just want to build an awkward escape room puzzle, this is a fun project to replicate.