mcu_board is a simple, custom-designed breakout board for the STM32F042 microcontroller. The goal of this project is to iterate on a prototype and try out different things, practice KiCad workflow, USB hardware implementation, STM32 firmware bring-up and so on. I choose the STM32F042 because it's simple to program using the USB bootloader (DFU) but in a later revision I will break out the SWD pins so that it can be programmed with a STLink debugger/programmer.
Microcontroller: STM32F042 (ARM Cortex-M0)
Connectivity: USB 2.0 Full Speed (Type-C but should be replaced with a Type-A for compatibility with the DFU bootloader)
I/O: Full GPIO breakout to standard 2.54mm headers
Power: USB-powered (5V converted to 3.3V via LDO)
Debug: SWD (Serial Wire Debug) header for programming via ST-Link