How to Fix 'avrdude: stk500_recv programmer is not responding' Error While Uploading Sketch to Arduino Pro Mini?

The classic error message 'avrdude: stk500_recv programmer is not responding' can occur in several scenarios, and diagnosis typically involves checking basic configurations and physical connections. Here's a comprehensive guide on how to resolve this issue.

Common Causes and Solutions

When you face the 'avrdude: stk500_recv programmer is not responding' error, there are a few common causes to investigate:

1. Incorrect COM Port Selection

Ensure that the correct COM port has been selected in the Arduino IDE. Sometimes, the COM port might be incorrectly identified, or it could be in use by another program. Here’s what to do:

Disconnect the Arduino from the computer and reconnect it to a different USB port. Check the settings in the Arduino IDE to ensure the correct COM port is selected.

2. Incorrect Board Selection

Make sure that the correct board type is specified in the Arduino IDE. The Mini and Pro Mini boards are different, and selecting the wrong one can trigger this error. You can double-check this by going to Tools > Board and verifying that the correct board is selected.

3. Reinstallation of Arduino Software

If you have tried the above steps and still face the error, it might be worth reinstalling the Arduino IDE. Often, reinstalling the software can resolve underlying issues.

Advanced Troubleshooting Steps

If you have confirmed that the correct COM port and board are selected, but the error persists, you need to gather more detailed information. Enabling verbose mode in avrdude can provide insights into what's going wrong. Here’s how to do it:

4. Enabling Verbose Mode in avrdude

To enable verbose mode, go to Tools > Preferences in the Arduino IDE. Check the box for 'Show verbose output during upload'. When you upload your sketch, the additional output will be more detailed. You can also manually run the following command from the command line:

avrdude -v -v -v -v -C -patmega328 -P/dev/usbport -U flash:w:/path/to/firmware.hex

Note that you need to replace /dev/usbport with the actual COM port, and /path/to/firmware.hex with the path to your sketch.

5. Analyzing the Output

The verbose output from avrdude can help you identify the exact point of failure. Here are some specific things to look out for:

Check if the cable and/or connectors have microcuts. Verify if there is a shortcut on the PCB between Rx and Tx (pins 1 and 0). Ensure the ATmega chip is not out of power. Confirm if the 0 and 1 pins of the Arduino are being used by a shield or custom design (not applicable to the Leonardo). Check if the USB to UART converter (FTDI on older Duemilanove or Atmega16U2 on newer Uno) is functioning correctly. Verify if the Atmega328 chip is correctly installed and not fried. Check if the bootloader has been overwritten or is failing.

Using the verbose mode can help narrow down the issue by giving detailed information about the connection and communication process.

Additional Tips and Considerations

If you have swapped the position of the ATmega chip and it's no longer working, remember that placing the power source on digital pins may have damaged the chip. Here are a few more considerations:

Double-check all connections before starting the upload process. Ensure power is applied correctly to the chip. Use the correct programming cables and software versions. Consult the Arduino Pro Mini documentation for specific setup instructions.

By following these steps and tips, you should be able to resolve the 'avrdude: stk500_recv programmer is not responding' error and successfully upload your sketch to the Arduino Pro Mini.