ESP32 Slot Car Speed Controller

Racing slot cars – based on my passing familiarity and a set I enjoyed decades ago as a child – involves mashing a simple trigger for analog-ish control of tiny electrically powered cars... until they eventually fly off the track. Slot car technology, however, has apparently advanced since then, with controllers that are far more capable, but that can cost well over $100.

Here Maker Fabio presents another option: a DIY slot car speed controller, with fantastic programmability, that can be made for around $20. Of course, you’ll need to put in some work (and have a 3D printer) to produce this controller, but the results appear to be well worth it if you’re a serious (or soon-to-be-serious) slot car aficionado.

The heart of the design computing-wise is an ESP32 dev board, which takes input from the trigger via a hall effect sensor. User feedback is accomplished using a a small OLED display and power output is handled by a MOSFET. The housing is 3D-printed on a Bambu multi-color unit, and while the build files are still a work in progress, once it's in a state that can be duplicated, you could presumably also customize it to fit your needs/style.

The trigger movement limit and pull strength are adjusted via a pair of screws, and the OLED menu allows the user to change a variety of car/racing parameters. The amount of customization that’s available for this one single trigger input is extremely impressive. Check out the video to see how it works, as well as the overall build process: