How to Use STM32F103 Blue Pill: Examples, Pinouts, and Specs

The STM32F103 Blue Pill is a compact and affordable microcontroller development board based on the STM32F103C8T6 chip, manufactured by STM32. It features a 32-bit ARM Cortex-M3 core, 64KB of flash memory, and a wide range of I/O pins, making it a versatile choice for embedded systems and IoT projects. Its small form factor and low cost make it popular among hobbyists, students, and professionals alike.

• Prototyping embedded systems
• IoT devices and smart home applications
• Robotics and motor control
• Data acquisition and sensor interfacing
• Educational projects for learning ARM Cortex-M3 architecture

The STM32F103 Blue Pill offers the following key technical details:

The STM32F103 Blue Pill has a total of 40 pins, including GPIO, power, and communication pins. Below is a summary of the pin configuration:

1. Powering the Board:

   • Connect the board to a 5V power source via the USB port or the 5V pin.
   • Ensure the power supply is stable and within the specified voltage range.

2. Programming the Board:

   • Use an ST-Link programmer or a USB-to-serial adapter to upload code.
   • Install the STM32CubeIDE or the Arduino IDE with the STM32 core for development.

3. Connecting Peripherals:

   • Use the GPIO pins for interfacing with sensors, actuators, and other devices.
   • For analog inputs, connect sensors to the A0–A7 pins.

4. Boot Mode Selection:

   • Set the BOOT0 pin to 0 for normal operation or 1 for programming mode.

• Always use a 3.3V logic level for GPIO pins to avoid damaging the microcontroller.
• Use decoupling capacitors near the power pins to ensure stable operation.
• Avoid drawing excessive current from the 3.3V pin, as it is limited in output capacity.
• When using USB for communication, ensure proper grounding to avoid noise issues.

Below is an example of how to blink an LED connected to pin D13 using the Arduino IDE:

// Blink an LED on pin D13 of the STM32F103 Blue Pill
// Ensure the STM32 core is installed in the Arduino IDE

void setup() {
  pinMode(PC13, OUTPUT); // Set pin PC13 (D13) as an output
}

void loop() {
  digitalWrite(PC13, HIGH); // Turn the LED on
  delay(1000);              // Wait for 1 second
  digitalWrite(PC13, LOW);  // Turn the LED off
  delay(1000);              // Wait for 1 second
}

1. The board is not recognized by the computer:

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

2. Code upload fails:

   • Verify that the BOOT0 pin is set to the correct position for programming mode.
   • Ensure the correct COM port and board settings are selected in the IDE.

3. The board does not power on:

   • Check the power supply voltage and connections.
   • Inspect the board for any visible damage or loose components.

4. GPIO pins are not responding:

   • Confirm that the pins are configured correctly in the code.
   • Check for short circuits or incorrect wiring.

Q: Can I use 5V logic devices with the STM32F103 Blue Pill?
A: No, the GPIO pins operate at 3.3V logic levels. Use a level shifter if interfacing with 5V devices.

Q: How do I reset the board?
A: Press the onboard reset button or toggle the NRST pin.

Q: Can I use the Arduino IDE for programming?
A: Yes, the STM32 Blue Pill is compatible with the Arduino IDE after installing the STM32 core.

Q: What is the maximum current output of the 3.3V pin?
A: The 3.3V pin can supply a maximum of approximately 100 mA. Avoid exceeding this limit.