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If there are "Unknown" devices in the board selector or ports without a board name in the Tools > Port menu

Learn how to troubleshoot and resolve cases where the Arduino IDE shows “Unknown” devices or fails to assign a board name in the board selector and Tools > Port menu.

In this article:

Understanding port detection

The Arduino IDE scans the ports on your computer for devices that might be compatible boards. These detected serial ports are shown in both the board selector and the Tools > Port menu.

  • Identified Devices: If the Arduino IDE recognizes a device as an Arduino board, it displays the board and port in the board selector. In the Tools > Port menu, the board name appears after the port name, enclosed in parentheses.

  • Unidentified Devices: In some cases, the port information is not sufficient to determine the type of board that’s connected, or if the connected device is a compatible board at all. In this case, the device will appear as “Unknown” in the board selector, and only the port name will be shown in the Tools > Port menu.

This example shows the board selector and Tools > Port menu on Windows when an Arduino UNO board and one other unidentified device is connected:

Identified and unidentified ports in the board selector (left) and Tools > Port menu (right).

Types of unidentified ports

The types of unidentified ports shown by Arduino IDE can be grouped in two categories:

  • Arduino-compatible boards that use generic USB chips:
    • The “classic” Arduino Nano, which uses a FTDI USB chip.
    • Various “clone” board with generic USB chips such as the CH340.
  • Ports that do not belong to an Arduino-compatible device, but are detected and shown by Arduino IDE anyway:
    • Some non-Arduino devices with generic USB chips.
    • Some Bluetooth ports.
    • Debug ports.

Note

If you have many unidentified ports showing up in the list, consider disconnecting any boards and peripherals you don’t need from your computer. Then, use this procedure to see whether your board is being detected on any of the ports.

Troubleshooting steps

1. Disconnect and reconnect your board to check its port

Using the board selector:

  1. Disconnect your board from your computer.

  2. Open the board selector menu.

  3. Connect your board to your computer.

Using the Tools > Board menu:

  1. Disconnect your board from your computer.

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

  3. Connect your board to your computer.

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

2. Configure an unidentified board

If you’ve determined which port belongs to your board:

Using the board selector:

  1. Open the board selector.

  2. Select the “Unknown” board you want to use.

  3. In the pop-up “Select Other Board and Port” menu, select the board from the list.

  4. Click OK.

Using the Tools > Board menu:

  1. Open the Tools > Board menu.

  2. Choose the board you want to use.

For more information, see Select board and port in Arduino IDE.

Still need help?

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