2025
I Built a Bike-Powered Minecart to Exercise in Minecraft
I connected an exercise bike to Minecraft so real pedaling controls minecart speed while an Ender Dragon chases me.
Video summary
I turned an exercise bike into a Minecraft controller so pedaling in real life controls a minecart in-game. The video starts with reverse engineering the bike’s original speed sensor, then builds up to a full challenge where my pedaling speed moves the cart while an Ender Dragon chases me through an amplified Minecraft world.
What I built
I traced the bike wiring to a magnet and hall effect sensor, intercepted that signal with a Raspberry Pi, soldered a 3.5 mm jack connector, and designed a 3D printed case with magnets so the Pi module could mount directly to the bike. I also hosted a small web server from the Pi that broadcasts real-time RPM data and built a display to show speed and RPM over time.
Technical takeaways
I converted wheel RPM into ground speed using the wheel diameter, then mapped that speed into Minecraft blocks per second. I wrote plugins to move the minecart, place rails ahead of the player, break blocks around the route, track distance, and run the dragon chase. The result tied together sensors, soldering, networking, game plugin development, and a physical fitness challenge that was harder than expected once the dragon got close.