STM32F103C8T6 (Blue Pill)

The STM32F103C8T6, popularly known as the Blue Pill, is a powerful and cost-effective ARM Cortex-M3 microcontroller from STMicroelectronics.

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19 June 2023 by Kevin McAleer | Share this article on


The STM32F103C8T6, commonly referred to as the Blue Pill, is an ARM Cortex-M3 microcontroller that has gained immense popularity due to its robust features combined with its affordable price. This 32-bit microcontroller offers a perfect balance of performance and features, making it a go-to choice for many embedded projects.

About the Manufacturer

STMicroelectronics is a global leader in the semiconductor industry, known for its wide range of microcontrollers, sensors, and other electronic components. Their STM32 series, under which the Blue Pill falls, stands out for its scalability and performance.

Target Audience

Whether you’re a student, hobbyist, or a professional embedded systems developer, the Blue Pill is an attractive option. Its low cost and powerful capabilities make it an excellent platform for learning, prototyping, and even production in certain applications.

Onboard Features and Specifications

  • Core: ARM Cortex-M3 running at up to 72 MHz.
  • Memory: 64KB of Flash memory and 20KB of SRAM.
  • Peripherals: Includes UART, SPI, I2C, timers, ADC, and more.
  • I/O: Up to 37 GPIO pins.
  • Connectivity: 2x12 pin headers with a pitch of 2.54 mm.

Programming Languages

You can program the Blue Pill using the C/C++ languages with the STM32Cube IDE and HAL libraries provided by STMicroelectronics. There’s also a core available for the Arduino IDE, allowing for easier development for those familiar with the Arduino platform. MicroPython and mbed platforms also support this microcontroller, offering even more versatility.

Fun Projects

The Blue Pill can be used in a myriad of projects:

  • Weather Station: Use its ADC to read values from temperature and humidity sensors.
  • Smart Lighting: Control LED strips or individual LEDs using its GPIO pins.
  • DIY Game Console: Pair it with a small screen and buttons to create your own handheld gaming device.

GPIO Pinouts

The Blue Pill provides:

  • General GPIO: Digital input/output pins.
  • Power pins: Labeled as 3.3V and GND.
  • Analog pins: Connected to the onboard ADC.
  • Communication pins: Including I2C, SPI, and USART.

Always refer to the STM32F103C8T6 datasheet and reference manual for detailed pin functionalities.

In conclusion, the STM32F103C8T6 or the Blue Pill stands out as a remarkable microcontroller in the STM32 series. Its blend of affordability, features, and performance makes it a favorite among many in the embedded world.

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