Motorizing a
20-Year-Old Lego Car
I installed an ESP32, a stepper motor, and LED headlights into a 20-year-old Lego car, then built a custom iPad app to drive it. The wiring is a mess but it works.
The brains (ESP32-C3)
I pulled out the original Lego seating and internals and strapped in a custom protoboard with an ESP32-C3 Super Mini, running a custom Bluetooth (BLE) server that connects instantly to my iPad.
The drivetrain
The original DC motor couldn't handle the added weight, so I swapped in a stepper motor on a ULN2003 driver board. Finally enough torque to push its own weight without stalling.
The native iOS app
A custom app built from scratch with SwiftUI and CoreBluetooth for real-time control — including a toggle for the yellow LED headlights, honestly my favorite part of the build.