How to Use STM32F103C8T6 Blue Pill: Examples, Pinouts, and Specs

The STM32F103C8T6 Blue Pill is a compact and affordable microcontroller development board based on the STM32F103C8T6 chip. It features a 32-bit ARM Cortex-M3 core, 64KB of flash memory, and a wide range of I/O ports, making it ideal for prototyping and embedded applications. Its small form factor and low cost make it a popular choice among hobbyists, students, and professionals for developing IoT devices, robotics, and other embedded systems.

• IoT devices and smart home automation
• Robotics and motor control
• Data acquisition and sensor interfacing
• Low-power embedded systems
• Educational projects and prototyping

The STM32F103C8T6 Blue Pill has two rows of 20 pins each. Below is a summary of the pin configuration:

1. Powering the Board:

   • The board can be powered via the 5V pin or through the micro-USB port. Ensure the input voltage does not exceed 5V.
   • The onboard voltage regulator converts 5V to 3.3V for the microcontroller.

2. Programming the Board:

   • The Blue Pill can be programmed using the Arduino IDE, STM32CubeIDE, or other compatible tools.
   • To upload code, connect the board to your computer via a USB-to-Serial adapter or use an ST-Link programmer.

3. Boot Mode Selection:

   • Use the BOOT0 pin to select the boot mode:
     • 0: Boot from flash memory (default mode for running user programs).
     • 1: Boot from system memory (used for programming via UART).

4. Connecting Peripherals:

   • Use the GPIO pins for interfacing with sensors, actuators, and other devices.
   • Configure the pins in software for digital I/O, ADC, PWM, or communication protocols.

• Voltage Levels: The GPIO pins operate at 3.3V. Avoid connecting 5V signals directly to the pins to prevent damage.
• Pull-Up/Down Resistors: Some pins may require external pull-up or pull-down resistors depending on the application.
• Clock Configuration: Ensure the correct clock settings in your code for optimal performance.

Below is an example of how to blink an LED connected to pin PA5:

// Define the pin for the LED
#define LED_PIN PA5

void setup() {
  pinMode(LED_PIN, OUTPUT); // Set PA5 as an output pin
}

void loop() {
  digitalWrite(LED_PIN, HIGH); // Turn the LED on
  delay(500);                  // Wait for 500 milliseconds
  digitalWrite(LED_PIN, LOW);  // Turn the LED off
  delay(500);                  // Wait for 500 milliseconds
}

1. Board Not Detected by Computer:

   • Ensure the correct drivers are installed for the USB-to-Serial adapter or ST-Link programmer.
   • Check the USB cable for damage or try a different cable.

2. Code Upload Fails:

   • Verify the BOOT0 pin is set to the correct position for programming.
   • Ensure the correct board and port are selected in the Arduino IDE or STM32CubeIDE.

3. GPIO Pins Not Responding:

   • Check the pin configuration in your code.
   • Ensure the connected peripherals are functioning correctly and powered properly.

4. Overheating:

   • Verify the input voltage does not exceed 5V.
   • Check for short circuits in your circuit connections.

Q: Can I use the Blue Pill with 5V sensors?
A: Yes, but you will need a level shifter to safely interface 5V signals with the 3.3V GPIO pins.

Q: How do I reset the board?
A: Press the onboard reset button or momentarily connect the NRST pin to GND.

Q: Can I use the Blue Pill for USB communication?
A: Yes, the STM32F103C8T6 supports USB communication. You can use libraries like USB HID or CDC for implementing USB functionality.

Q: What is the maximum current output of the 3.3V pin?
A: The 3.3V pin can supply up to 100 mA, depending on the input voltage and load.

This concludes the documentation for the STM32F103C8T6 Blue Pill.