Why Boot Mode?
ESP32 devices (C3 and S3) must be in boot mode to accept new firmware.
This mode allows the device to receive and flash new code.
How to Enter Boot Mode:
For XIAO ESP32-C3 and XIAO ESP32-S3:
- Hold down the BOOT button on your
device
- While holding BOOT, press and release the
RESET button
- Release the BOOT button
- Your device is now in boot mode and ready for firmware installation
Troubleshooting:
• Make sure your USB cable supports data transfer (not just power)
• Try a different USB port on your computer
• Verify the device appears in your browser's serial port list
• Some boards may require holding BOOT before plugging in USB
• For ESP32-S3, try using a different USB cable or port if detection fails
• After flashing completes, press RESET to start the device normally
💡 Tip: If flashing fails, try entering
boot mode again and click "Install
Firmware" once more. ESP32-S3 may take slightly longer to detect.