# Adafruit Feather STM32F405 Express onekey * Supported Hardware: [Adafruit Feather STM32F405 Express](https://www.adafruit.com/product/4382) To trigger keypress, short together pins *GPIO 12 / PC2* and *GPIO 11 / PC3*. https://learn.adafruit.com/adafruit-stm32f405-feather-express/dfu-bootloader-details#enabling-dfu-bootloader-mode-3045622-2