These “Blue Pill” STM32 modules are equipped with the original STM32F103C8T6 microcontroller. UNIVERSAL-SOLDER modules also have the right resistor value installed on D+ USB line, to avoid the known issues with modules from other manufacturers. “Blue Pill” is a microcontroller minimum system module about the size of an Arduino NANO, but at least 5x as fast, with much more I/O ports, 4x higher A/D resolution, 4x higher PWM resolution. The operating voltage of 3.3V is generated onboard from a 5V input voltage, for example from the USB port. A supply with an external 3.3V source is also possible. Most of the ports can handle 3.3V and 5V logic level as well. Some of the features: – 29 I/O ports, thereof 15 PWM out and 10 analog in – Real Time Clock with Quartz 32kHz and backup battery input – 2 x I2C bus, 3 x serial interface (GPIO) – only 53 x 22 mm small – 72MHz internal clock speed for high processing power – on board ST-Link header for in-circuit programming/debugging – 3.3V device with 5V tolerant I/O ports (most of them) Our STM32 module has 40 pins, and it fits in a DIP40 socket. The pin headers are already assembled.