How to Use ST-Link v2: Examples, Pinouts, and Specs

The ST-Link v2 is a versatile programming and debugging tool designed for STM32 microcontrollers. It provides a seamless interface for developers to upload firmware, debug applications, and monitor real-time performance via a USB connection. Compact and easy to use, the ST-Link v2 is an essential tool for embedded systems development.

• Programming STM32 microcontrollers with custom firmware.
• Debugging embedded applications using breakpoints and step-through execution.
• Real-time monitoring of variables and system performance.
• Flashing bootloaders or firmware updates in production environments.
• Educational purposes for learning STM32 development.

• Supported Microcontrollers: STM32 ARM Cortex-M series.
• Interface: USB 2.0 (Type-A to Mini-B or Micro-B, depending on the model).
• Programming Protocols: SWD (Serial Wire Debug) and JTAG.
• Voltage Levels: Supports target voltages from 1.65V to 3.6V.
• Operating System Compatibility: Windows, macOS, Linux (with appropriate drivers).
• Software Support: STM32CubeIDE, Keil uVision, IAR Embedded Workbench, OpenOCD.

The ST-Link v2 typically uses a 4-pin or 6-pin header for connecting to the target microcontroller. Below is the pinout for the 4-pin SWD interface:

For the 6-pin JTAG interface, the additional pins are:

1. Connect the ST-Link v2 to the Target Microcontroller:

   • Use the SWD or JTAG interface to connect the ST-Link v2 to the STM32 microcontroller.
   • Ensure the VCC pin matches the target microcontroller's voltage level.

2. Install Required Software:

   • Download and install STM32CubeIDE or another compatible IDE.
   • Install the ST-Link USB driver (available on the STMicroelectronics website).

3. Power the Target Device:

   • Ensure the target microcontroller is powered either externally or via the VCC pin of the ST-Link v2.

4. Program the Microcontroller:

   • Open the IDE and configure the ST-Link v2 as the debugger/programmer.
   • Load the firmware or project into the IDE and click "Program" or "Debug".

5. Debugging:

   • Set breakpoints, watch variables, and step through the code using the IDE's debugging tools.

• Always verify the target microcontroller's voltage level before connecting the ST-Link v2.
• Use short, high-quality cables to minimize signal interference.
• Avoid powering the target device solely through the ST-Link v2 if it requires high current.
• Ensure the ST-Link v2 firmware is up to date for compatibility with the latest STM32 devices.

The ST-Link v2 can also be used to program STM32 microcontrollers via the Arduino IDE. Below is an example of uploading a simple "Blink" program to an STM32 board:

// Example: Blink an LED on an STM32 board using Arduino IDE
// Ensure the ST-Link v2 is connected to the STM32 board via SWD interface.

void setup() {
  pinMode(LED_BUILTIN, OUTPUT); // Set the built-in LED pin as output
}

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

To upload this code:

1. Install the STM32 board package in the Arduino IDE.
2. Select the appropriate STM32 board and "ST-Link" as the upload method.
3. Click "Upload" to program the microcontroller.

1. ST-Link v2 Not Detected by the IDE:

   • Ensure the ST-Link USB driver is installed correctly.
   • Check the USB cable and port for proper connection.
   • Update the ST-Link firmware using the ST-Link Utility.

2. Programming Fails or Debugger Disconnects:

   • Verify the SWD or JTAG connections are secure and correctly oriented.
   • Check the target microcontroller's power supply.
   • Ensure the correct target voltage is selected.

3. Target Microcontroller Not Responding:

   • Confirm the microcontroller is not in a low-power or reset state.
   • Check for any hardware issues, such as damaged pins or incorrect wiring.

4. Firmware Update Required:

   • Use the ST-Link Utility to update the firmware to the latest version.

Q: Can the ST-Link v2 power the target microcontroller?
A: The ST-Link v2 can provide a reference voltage (VCC) but is not designed to power the target device. Use an external power source for the microcontroller.

Q: Is the ST-Link v2 compatible with non-STM32 microcontrollers?
A: The ST-Link v2 is primarily designed for STM32 devices. However, it may work with other ARM Cortex-M microcontrollers using OpenOCD.

Q: How do I update the ST-Link v2 firmware?
A: Download the ST-Link Utility from the STMicroelectronics website, connect the ST-Link v2, and follow the on-screen instructions to update the firmware.

Q: Can I use the ST-Link v2 with Linux?
A: Yes, the ST-Link v2 is compatible with Linux. Install OpenOCD or other compatible tools to use it on Linux systems.