MATLAB–Arduino Connection Issues

Error

Error: MATLAB Cannot Connect to the Arduino Serial Port

The example below shows a connection error that occurs when MATLAB cannot communicate with the Arduino board. This typically happens when the serial port is not available, the board was not configured correctly, or another program is using the port.

Figure 1: Error: “Invalid operation. Object must be connected to the serial port.”

Screenshot of figure 1 as described above

To fix this issue, verify the following:

  • USB connection is secure, and the board is powered.
  • The correct COM port was selected during setup (arduinosetup).
  • The MATLAB server was successfully uploaded (look for “success!” in Step 7).
  • Close any program using the port (Arduino IDE, Serial Monitor).
  • Restart MATLAB if the error continues.