STM32F103C8T6 “Blue Pill” Processor Module



5 in stock


This is a very low cost ARM processor board available out of China for a few dollars each. It is an excellent way to get your feet wet in the world of 32bit ARM processors for less than $20 including the ST-Link V2 hardware programmer / debugger also available here. Also look for our getting started combo including this board and the ST-Link V2 here.

The board has been named the “Blue Pill” by a number of groups and there are several variants of it out there. It sports an ST Micro STM32F103C8T6 ARM Cortex M3 processor in a QFP-48 package and is capable of running at internal speeds of up to 72MHz. It comes in a DIP-40 style module with standard 0.100″ pitch headers making it easy to prototype with.

It is supported by the ST Micro True Studio development environment and the STM32CubeMX code initialization tool for rapid code development and real, step-by-step hardware debugging. All for free. All you need is the processor board and a low cost ST-Link V2 Programmer/Debugger.

It is also compatible with the Arduino and Mbed environments if you like continuing to play in the sandbox of programming but I do not support it and you will have to find out on your own how to do this. If you are really interested in big boy processors and not toys you will learn to use professional tools. You will never look back and regret it. I have a getting started project on the Celeritous Github site with heavily commented code to help get started even faster.

Features of the board include:

  • STM32F103C8T6 32bit Cortex M3 ARM processor
    • 64KBytes of flash (some actually have 128K usable –  but don’t count on it)
    • 20KBytes of SRAM
    • No EEPROM
    • 72MHz internal clock rate
    • 2.0 – 3.3V operation (This is not 5V compatible!)
    • JTAG Serial Wire programming / Debug
    • 2 x 12bit A/D Converters
    • 7 Timers – 3 16bit, 1 16bit motor control PWM, 2 watchdog, Systick
    • 2 I2C Ports
    • 3 USARTS
    • 2 SPI Ports
    • 1 CAN Bus Port Master
    • Battery Backed Real Time Clock
    • 1 USB FS interface
    • Internal CRC calculator
  • up to 37 GPIO
  • Reset Button
  • Boot Mode Jumpers
  • 8MHz and 32.768KHz Crystals
  • SWD Debug Header
  • On-board 5V to 3.3V regulator
  • USB Port – Micro B Connector

More information on these boards can be found on the Blue Pill Wiki including pinouts, photos, schematics, similar boards, etc.

A direct link to the pinout diagram is here

There are a number of known issues with these boards that require user correction or inspection. All units sold by Celeritous have the following known issues addressed and fixed for you.

  • USB D+ Pull-up resistor is normally 10K which will prevent proper enumeration. This is an 0603 part and difficult for some users to correct. All Celeritous units have this replaced with the proper 1.5K 0603 resistor
  • Most units are shipped without the headers being soldered. All Celeritous units will have the headers pre-soldered and done in a ZIF socket fixture to make sure the headers are properly aligned.
  • Most units have surface mount micro USB connectors and are very easy to strip off the board if any torque or excessive force is applied during insertion or removal of the USB connector. In addition many USB connections are cold. All Celeritous units have the hold-down tabs re-soldered and the USB connections check and touched up if required.
  • A general visual inspection is made of the board to make sure there are no obvious cold solder joints.
  • We do not do a functional test of the boards.

Additional information

Weight 8 oz
Dimensions 6 × 6 × 1 in

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.