How to Use STM32F103C8T6(2): Examples, Pinouts, and Specs

The STM32F103C8T6 is a 32-bit ARM Cortex-M3 microcontroller manufactured by STMicroelectronics. It features 64KB of flash memory and 20KB of SRAM, making it a versatile and high-performance solution for a wide range of embedded systems. This microcontroller is part of the STM32 family, known for its low power consumption, robust peripherals, and ease of integration.

• Industrial automation and control systems
• IoT devices and smart home applications
• Robotics and motor control
• Consumer electronics
• Data acquisition and signal processing
• Prototyping and development with platforms like Arduino or custom PCBs

The STM32F103C8T6 microcontroller offers the following key technical features:

The STM32F103C8T6 has 48 pins, with the most commonly used pins described below:

For a complete pinout, refer to the STM32F103C8T6 datasheet.

1. Power Supply: Connect VDD to a 3.3V power source and VSS to ground. Ensure proper decoupling capacitors (e.g., 0.1 µF) are placed close to the VDD pins.
2. Clock Configuration: Use an external 8 MHz crystal oscillator connected to OSC_IN and OSC_OUT, along with appropriate load capacitors (typically 22 pF).
3. Boot Mode Selection: Use the BOOT0 pin to select the boot mode:
   • Connect BOOT0 to GND for normal Flash memory boot.
   • Connect BOOT0 to VDD for system memory boot (e.g., for firmware updates).
4. Programming: Use an ST-Link programmer or USB-to-serial adapter to upload firmware via the SWD (Serial Wire Debug) interface or USART1.
5. GPIO Configuration: Configure GPIO pins as input, output, or alternate function using the STM32 HAL (Hardware Abstraction Layer) or direct register programming.

• Power Supply Stability: Ensure a stable 3.3V power supply with proper decoupling to avoid noise issues.
• Clock Source: For precise timing, use an external crystal oscillator. Internal RC oscillators are less accurate.
• Debugging: Use the SWD interface for debugging and firmware uploads.
• Peripheral Configuration: Use STM32CubeMX to generate initialization code for peripherals, reducing development time.
• Heat Dissipation: While the STM32F103C8T6 is efficient, ensure proper ventilation or heat sinking in high-performance applications.

The STM32F103C8T6 can be programmed using the Arduino IDE with the STM32duino core. Below is an example of blinking an LED connected to pin PA5:

// Example: Blink an LED on PA5 using STM32F103C8T6
// Ensure STM32duino core is installed in Arduino IDE

#define LED_PIN PA5  // Define the 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(1000);                  // Wait for 1 second
  digitalWrite(LED_PIN, LOW);   // Turn the LED off
  delay(1000);                  // Wait for 1 second
}

1. Microcontroller Not Responding

   • Cause: Incorrect power supply or missing decoupling capacitors.
   • Solution: Verify the power supply voltage (3.3V) and add decoupling capacitors near VDD pins.

2. Unable to Upload Code

   • Cause: Incorrect BOOT0 pin configuration or faulty programmer connection.
   • Solution: Ensure BOOT0 is set to GND for Flash memory boot. Check connections to the ST-Link or USB-to-serial adapter.

3. Clock Issues

   • Cause: Improper external crystal oscillator setup.
   • Solution: Verify the crystal oscillator frequency and load capacitor values.

4. GPIO Pins Not Working

   • Cause: Incorrect pin configuration or peripheral conflict.
   • Solution: Check the pin configuration in the code and ensure no conflicts with other peripherals.

• Q: Can I use the STM32F103C8T6 with 5V logic?
  A: No, the STM32F103C8T6 operates at 3.3V. Use level shifters for interfacing with 5V logic.

• Q: How do I reset the microcontroller?
  A: Use the NRST pin or software reset via the system control register.

• Q: What development tools are recommended?
  A: STM32CubeIDE, Keil uVision, or Arduino IDE with STM32duino core.

• Q: Can I use the internal oscillator instead of an external crystal?
  A: Yes, but the internal oscillator is less accurate and may not be suitable for timing-critical applications.