Error writing IOServerBlock when trying to write to an Arduino

I was running a long script to read from a sensor connected to an Arduino, and after a while I saw that the script had stopped and had reported the following error:

Error writing IOServerBlock.
Invalid operation. Object must be connected to the serial port.

I did not change anything in the script, and I verified everything was still properly wired to the Arduino, so what may have caused this error, and how can I resolve it?

Answer 1

[MathWorks Support Team]

Possible Explanation:

Most likely, this error was caused by the Arduino losing connection to your computer while a script is running. This can happen from simply bumping the USB Cable and accidentally disconnecting the Arduino temporarily, or if the computer goes to sleep in the middle of a script. Even if the Arduino is reconnected, the error may still be generated.

Resolution:

To resolve this issue, ensure the Arduino is connected, then delete the Arduino variable, and re-instantiate it.

For example, if your Arduino variable is "a", then execute the following:

%% Assumes an Arduino variable 'a' is already instantiated

% Delete existing Arduino variable
clear a

% Re-instantiate Arduino variable
a = arduino(); % include all parameters from your original call