A breakout board with STM32F042F6. This can also handle STM32F030F4. Very small, cute and breadboard friendly. This little MCU is Corex M0 32 bit, 48Mhz, 32Kb Flash, 6Kb SRAM and contain a long list of IO including touch contacts. The board include x-tal (not mounted here) and a 3.3V PSU that also can act as a PSU for the rest of your design. The SWD Connector is available at top, so you can also Mount this vertical to save Space if you only need a few pins.