This is a hobby project using an STM32 microcontroller to control WS2815 LED strips over ethernet. While it’s a fun interesting setup, it’s still a work in progress, so the design and code have plenty of room for improvement.
The controller is built around a custom PCB and features:
- Microcontroller: STM32G0B0RE, which handles LED effects, strip control, and MQTT connection.
- Ethernet: W5500 chip (from Wiznet) for simple 100/10 ethernet functionality.
- LED Connection: 4-pin connector for attaching WS2815 LED strips.
- Debugging Options:
- SWD (Serial Wire Debug): Required for flashing firmware.
- USB-C Port: Used mainly for serial output, with optional 5V power.
- Power Setup:
- 12V Power Connector: Powers the LED strip, switched on/off with a software-controlled load switch. The power connector is subject to change in a future board REV but for now the power leads are attached using M4 machine screws.
- Buck Converter: Steps down 12V to 5V for the data signals to the LEDs and to power the STM32 and ethernet chip.
Known Issues:
- The pads' hole size for the 4-pin LED strip connector is too small to easily fit the wires.
The firmware is written in C++ with portability and extensibility as guiding principles:
- Connectivity: Includes partially complete, platform-independent abstractions for network interface, sockets, and MQTT client, allowing connection to MQTT servers. Implementations relies on open-source libraries but the design allows these libraries to be swapped out relatively easily.
- LED Strip Compatibility: The firmware’s design allows control beyond the WS2815, with flexibility for WS2812, WS2811, and potentially other types through a semi-extensible interface. Currently, communication is handled by DMA timers and a circular buffer, but this setup supports future implementations.
- Configurable, Extensible Architecture: Aiming for maximum configurability, the design focuses on semi-modular components that can be swapped or extended easily.
- Documentation: Classes are documented using Doxygen. You can find a compiled HTML version in the
Firmware/Docsfolder.
Known Issues:
- The MQTT connection intermittently drops despite active ethernet indicators (likely a bug in the reconnect code).
To try it out:
-
Connect Power and LEDs:
- Screw down a 12V power source onto the marked.
- Attach a WS2815 LED strip to the 4-pin connector.
-
Upload Firmware:
- Firmware currently needs to be flashed over the SWD connector.
-
Run and Debug:
- Connect the USB-C port for serial output or use SWD for debugging.
| Feature | Description |
|---|---|
| Microcontroller | STM32G0B0RE |
| Ethernet | W5500 (100/10 Ethernet) |
| LED Output Connector | 4-pin (for WS2815 LED strip) |
| Debugging | USB-C, SWD for flashing |
| Power Input | 12V screw terminal |
| Voltage Conversion | Buck converter (12V to 5V) |
| Data Buffer | SN74125N for 5V data signals |
| Regulator | 3.3V for STM32 and W5500 |
This project is more of a learning exercise in PCB design and STM32 programming, so it might not be the most optimized controller out there! Any feedback or suggestions are welcome.