STM32 Blue Micro Controller

The Blue Pill is a compact, low-cost development board powered by the STM32F103C8T6 — a 32-bit ARM Cortex-M3 microcontroller running up to 72 MHz. It features 64 KB (or optionally 128 KB) of flash memory and 20 KB of SRAM, giving you enough space for embedded applications. 

On the board, you’ll find around 37 GPIO pins, two 12-bit ADCs, and a variety of communication interfaces: 3× USART, 2× SPI, 2× I²C, CAN, and USB. It also has 7 timers, including a PWM-capable one, and supports low-power modes like sleep, stop, and standby. 

The operating voltage is 3.3 V, and the board includes a micro-USB connector for power and programming. Debugging is handled via SWD (Serial Wire Debug), making it compatible with tools like ST-Link.