Microcontroller hardware
STM32 development board.
A compact STM32 board with USB-C, microSD, and SWD.
Design complete · awaiting fabrication
View source on GitHub
- Board
- 24 × 44 mm
- Copper
- 4 layers
- MCU
- STM32F411
- GPIO
- 22 pins
I wanted a small, breadboard-compatible STM32 board with the connections I'd actually use: USB-C, a microSD socket, GPIO, and SWD for programming and debugging.
Layout
The four-layer layout uses components on both sides. It brings out 22 GPIO pins, including nine analog inputs, with additional header pins for power, boot, reset, and debugging. The MCU is an STM32F411CEU6.
USB, microSD, and debugging
USB-C carries the MCU’s USB connection, with USB protection on the board. The microSD socket connects over SPI2. SWDIO, SWCLK, reset, ground, and the 3.3 V reference are available on the header so the board can be programmed without relying on a working USB application.
Manufacturing files and firmware
I've prepared the Gerbers, bill of materials, placement files, and pinout. The starter firmware builds and includes the LED, user button, and USB serial. I haven't tested it on an assembled board yet, and the microSD connection still needs testing too.
Current status
The PCB design and manufacturing files are done. I'm waiting on funding to order assembled boards, so I haven't done the physical bring-up yet.
Next steps
- Order and inspect the first assembled boards.
- Check the supply rail and program the MCU over SWD.
- Test USB serial, buttons, GPIO, and the microSD connection.
