Arduino Nano ESP32 Stuck in DFU mode — No COM Port, All Flash Attempts Fail

Official Hardware Nano Family Nano ESP32
1

Hi, I’ve got an arduino nano esp32 that’s stuck in DFU mode. It doesn’t show up as a COM port, only as a USB DFU device in device manager. I’ve tried:

  • Pressing reset once and double-tapping reset
  • Arduino web flasher (never detects the board)
  • Using arduino-cli (but it can't see any ports)
  • esptool.py (fails to connect bc no serial port)
  • dfu-util (can't find correct firmware offsets for nano esp32)
  • different USB cables and ports

I’ve installed the arduino agent, tried chrome/edge, still no detection. I just want to restore the board to factory firmware so it shows up again as a normal serial device.

Any ideas? is there a way to fully recover this thing from DFU mode?

Thanks in advance.

2

Hello @cr_txt, sorry for the delay. Not sure what is happening on your board, but have a look at this procedure, it will definitely recover it :slight_smile: you only need the Arduino IDE and the Arduino ESP32 boards package. :hammer_and_wrench:
Let us know if you were able to reflash your Nano ESP32!

3

Thank you for replying!

The Arduino functions correctly on another PC, but not on mine. It appears that my system does not recognize any serial/COM port associated with the Arduino—only the DFU port is detected. I have attempted to reset the firmware and burn the bootloader (on the other computer, as mine fails to detect the COM port), but neither method was successful.

4

Maybe you are simply missing the Nano ESP32 drivers on your PC. Please follow this advice to get those! :slight_smile: