Overrun and Task Execution Time Profiling on Arduino

I am deploying my Simulink model to Arduino hardware (Uno) and running an External mode or PIL simulation. When I decrease the sample time of the model below a certain threshold, I no longer get sensible readings from my sensor connect to my Arduino. Why is this happening?

Answer 1

[MathWorks Support Team]

A likely cause of this issue is from task overruns. A task overrun occurs if the target hardware is still performing one instance of a task when the next instance of that task is scheduled to begin. To determine if you are encountering overruns, please refer to the following documentation page:

https://www.mathworks.com/help/simulink/supportpkg/arduino_ug/detect-and-fix-task-overruns-on-arduino-hardware.html

This page outlines the process for detecting overruns and some methods you can employ to mitigate them. Please note that an option is to upgrade from the Uno to an Arduino with a more powerful processor, such as the Due.

To get a better understanding of the parts of your model that are causing overruns, you can profile execution time for your model running on the Arduino in PIL. Execution time profiling can be configured with the option Configuration Parameters > Code Generation > Verification > Measure task execution time. Please refer to the following documentation page for more information on profiling the execution of your generated code:

https://www.mathworks.com/help/rtw/ug/execution-time-profiling-for-generated-code.html

You can use this feature to determine how the various parts of your model that are affecting overruns and the minimal sample time needed to run the model without overruns.