Blue Pill original STM32F103C8T6 with 72MHz - RTC - micro USB
The performance of this original STM32F103C8T6 USB Development Board is 5 times the performance of the typical "Arduino" MCU ATmega328P. It comes with plenty of I/O and periphery options, can be programmed using original ST Microelectronics tool chain, or the ST-Link V2 adapter for example