Learn how to reset the default Arduino bootloader on the Nano ESP32 using Arduino IDE.

These are some reasons you may want to reset the bootloader:

• Update the Arduino bootloader already on the board. This can resolve issues with Nano ESP32 being misidentified as other ESP32 boards.
• Restore the ability to upload regular Arduino sketches to a Nano ESP32 that has been flashed with the MicroPython firmware.

Before you begin, it is recommended to have the latest version of the Arduino ESP32 Boards or esp32 boards package installed using the Board Manager.

Follow these steps:

1. Connect a jumper cable between the GND and B1 pins. The RGB LED will turn on with a green or blue color.

   

2. While the GND and B1 pins are shorted, press the white RST button on the top of the board to reset the board to firmware download mode.

3. Remove the jumper cable. The RGB LED should stay on, in a purple or yellow color.

4. Open Arduino IDE.

5. Go to Tools > Port and select the board (it may be identified as an arbitrary ESP32 board).

6. Go to Tools > Board and select Arduino ESP32 Boards > Arduino Nano ESP32 (or esp32 > Arduino Nano ESP32 if you’re using the full esp32 package).

7. Open Tools > Programmer and ensure Esptool is selected.

8. Select Sketch > Upload Using Programmer to begin uploading the firmware.

   The process is complete when you see these lines:

   Leaving...
   Hard resetting via RTS pin...
   

9. Press the RST button on top of the board to exit firmware download mode.