Here are some steps you can follow to troubleshoot this issue:
1. Make sure the Arduino board is properly connected to your laptop via USB cable. Try using a different USB cable or port on your laptop.
2. Make sure that the Arduino driver is installed on your computer. You can check this by going to Device Manager on your Windows computer or System Information on your Mac and looking for the Arduino board under the Ports (COM & LPT) section.
3.Make sure that you have installed the correct version of the Simulink support package for your Arduino board. You can check this by going to the Add-Ons menu in MATLAB and selecting Manage Add-Ons.
4. Make sure that the firmware on your Arduino board is up to date. You can do this by going to the Tools menu in the Arduino IDE (IDE = Integrated Development Environment)and selecting Get Board Info.
5.Check the Simulink model: Make sure that the Simulink model is set up correctly. Double-check that the Arduino block is properly configured with the correct port and board type.
6.Make sure that the Simulink configuration is set up correctly. This includes the baud rate and the serial port.
If none of these steps work, you may need to contact technical support for the Simulink support package or the Arduino board manufacturer for further assistance or You can also refer to MathWorks Documentation.
