Adafruit Feather STM32F405 Express Breakout Board

Adafruit Feather STM32F405 Express Breakout Board is designed to run CircuitPython at a blistering 168MHz. A STEMMA QT / Qwiic port on the end has been included so the user can easily plug and play I2C sensors. With CircuitPython basics running on this board, it is fast to get all the drivers working. The user can then use the built-in plotter in Mu to instantly get sensor data displayed within 3 minutes of unboxing. MicroPython, CircuitPython, or Arduino IDE can be used with this board, with some caveats.

CircuitPython support is currently under development. Adafruit has digital IO, analog in/out, I2C, SPI, PWM working with more items on the way. Arduino is supported through the STM32duino. There's no auto-reset bootloader support, so the user has to pull the BOOT0 pin high and manually reset before uploading. MicroPython support is very solid, but Adafruit does not provide MicroPython libraries for sensors. This board is an extraordinarily fast Feather and is Adafruit's first foray into the STM32.


  • STM32F405 Cortex M4 with FPU and 1MB Flash, 168MHz speed
  • 192KB RAM total - 128KB RAM for general usage and 64KB program-only/cache RAM
  • 3.3V logic, but almost all pins are 5V compliant
  • USB C power and data - Adafruit's first USB C Feather
  • LiPo connector and charger
  • SD socket on the bottom, connected to SDIO port
  • 2MB SPI Flash chip
  • Built-in NeoPixel indicator
  • Qwiic/STEMMA-QT connector for fast I2C connectivity
  • Uses the built-in USB DFU bootloader to load the firmware (device does not come with a UF2 bootloader)
Publicado: 2020-01-24 | Actualizado: 2022-07-04