Learn what to do if your board does not appear in the port selection menu in Arduino IDE.
- One or more LEDs should be lit when the board is powered.
- The board needs to be connected to your computer with a data USB cable. A charge-only cable will not work.
- Make sure the USB cable is not damaged. Test your cable with a different device, or try using a different cable.
- Remove any connections to digital pins 0 (RX) and 1 (TX).
- Check that no other pins are unintentionally getting current.
Note: If the port menu is open, you need to close and re-open it for the list to refresh.
Missing or corrupted USB-to-Serial firmware can cause UNO and Mega boards to be recognized as any of the following:
- Unknown Device (Uno, missing on Windows 10)
- Unknown USB Device (Invalid Device Descriptor) (Uno, corrupted on Windows 10)
- Composite Device (Uno, missing on macOS)
- USB Device (Uno, corrupted on macOS)
- ATmega16u2 DFU
- Atmega8U2 DFU
Resolve the issue by flashing the USB-to-Serial firmware in DFU mode.
Check the FTDI drivers (Arduino Nano)
If you're using the original Arduino Nano, make sure the FTDI drivers are installed.