I understand that you are trying to train the RL (Reinforcement Learning) agent in MATLAB, but you are facing the error "External mode simulation is not supported for simulations started using the sim function."
Here, I am assuming that the sentence "use the train function in MATLAB" implies that the agent is to be trained independently of the Arduino board.
From the error provided,it seems that the model simulation mode is set to "external",as it was previously simulated using hardware by executing "Run with IO" option.
To resolve this issue, change the model simulation to non-hardware related mode (for example, "normal", "accelerator" etc.).
Refer to the following code snippet to change the simulation mode to "normal":
set_param(model,'SimulationMode','normal');
However if you want to simulate the model with simulation mode set to "external", you can change the simulation command to "start" and run it:
set_param(model,'SimulationCommand','start')
Refer to the following documentation to learn more about simulation in various modes:
I hope this help you in resolving the issue.
