Learn what to do if your board does not appear in the port selection menu in Arduino IDE.

Check if the computer is detecting a device on the port

Two cases should be separated:

• The computer recognizes the board as a device, but not as an Arduino board. The port is listed in the port menu, but the board name is not displayed, and sketches cannot be uploaded (read this if using the classic Nano).
• The board is not being registered by the computer at all.

To check whether the board is being recognized as a device, follow these steps:

1. Disconnect your board from your computer.

2. Open the port list Tools > Port. Some ports may still be listed. Take note of this, and close the menu.

3. Connect your board to your computer.

4. Open Tools > Port. The port your board is connected to should now appear as a new port in the list.

Continue with the following steps depending on the result:

• No device was detected
• Incorrect device detected

If no device is detected

Check board connections

Note: If the port menu is open, you need to close and re-open it for the list to refresh.

The most common reason for the board not being displayed on a port are a failing USB connection.

1. The board needs to be connected to your computer with a data USB cable.
2. Make sure the USB cable is not damaged. Test your cable with a different device, or try using a different cable.
3. Try using a different USB port on your computer.
4. If possible, connect the board directly to your computer instead of a through a hub.
5. Remove all connections to the board pins, especially to 0(RX) and 1(TX).

Reset the board

The board may be stuck in a state where it cannot communicate on the port.

1. Find the reset button on the board.

2. Click the button two times in succession.

   

3. Check the port menu again.

Note: If the port menu is open, you need to close and re-open it for the list to refresh.

If a device is detected incorrectly

Check the USB-to-Serial firmware

If your board is an Arduino Uno (Rev1 or Rev3) or an Arduino Mega, the USB-to-Serial firmware may be corrupted.

Windows:

1. Open the Device Manager.
2. Check the Other Devices section.

macOS:

1. Open the System Information app.
2. Check the Hardware > USB section.

Linux: Use a device manager of your choice, such as hardinfo To install hardinfo, open Terminal and run sudo apt install hardinfo. Then run hardinfo to open and look in Devices > USB Devices).

Missing or corrupted USB-to-Serial firmware can cause Uno and Mega boards to be recognized as any of the following:

• Unknown Device
• Unknown USB Device
• Composite Device
• USB Device
• ATmega16u2 DFU
• Atmega8U2 DFU

If your board is listed with one of these names you can resolve the issue by flashing the USB-to-serial firmware in DFU mode.

If you're using the classic Nano

Unlike most other boards, the board name will not be displayed for a port where an Arduino Nano is connected.

1. Disconnect your board from your computer.

2. Open the port list Tools > Port. Some ports may still be listed. Take note of this, and close the menu.

3. Connect your board to your computer.

4. Open Tools > Port. The port your board is connected to should now appear as a new port in the list.

Still need help?

• Visit the Installation & Troubleshooting category in the Arduino forum.
• Contact us