I am running simple LED blinking using Simulink and Arduino and i am running into this error
Build process completed successfully Error occurred while executing External Mode MEX-file 'ext_comm': Failed to connect to the target. A time-out occurred while waiting for the connection response from the target. Possible reasons for the time-out: a) The target is not switched on. b) The target is not connected to your host machine. c) The application for the model is not running on the target. You might have clicked the Stop button. If the Run button is not dimmed, click it. Otherwise, click the Build button, which downloads and runs your application on the target. Component:Simulink | Category:Block diagram error Unable to connect to the 'Arduino Uno' target for 'syched'.
What to do.
Have you tried manually setting the COM port to the accurate port? Another common issue that causes this - A MATLAB arduino object already exists. This would not allow you to do External mode at the same time and you have to clear the object before you do external mode.
If error still persists, please reach out to Technical support of MathWorks.