For hackers into model railways, customizing every detail and having full control over locomotives is paramount. A standard serial protocol for communication with model trains called DCC allows control over multiple locomotives on the same track. It uses modulation on top of the voltage rail to communicate and send commands. The OpenDec02 board not only decodes DCC packets, it also has a PID motor control loop for maintaining speed under varying loads. Auxiliary outputs are available for controlling on-board lighting.
The OpenDec02 is a 4-layer board with power planes, which help heatsink the motor controller. It can drive motors at up to 2.8A continuously, as long as the heat is dissipated. Being based around the venerable RP2040 dual-core ARM Cortex-M0+ chip, there is plenty of power and a huge number of existing libraries to incorporate and play with! The project is entirely open source, so you can modify the existing firmware to add any features you might want. The latest firmware comes flashed onto the 8MB flash so you can get started right away. Simply hook up the board to the locomotive’s motor and power supply, and it will start decoding DCC packets!
The project is based on a project by Gabriel Koppenstein but the layout has been updated and you can buy them pre-made instead of DIY fabrication. If you’re looking for a locomotive control board for your model railway, definitely take a look at the OpenDec02!
