How to catch the error thrown when unable to connect to an arduino?

I am trying to write some code that will scan the COM ports for an arduino, and if none are found I would like to throw my own error. So I would like to catch this error somehow: "Unable to find Arduino hardware at COM3. First argument must be a valid serial port, IP address/hostname or Bluetooth address/name."

Is there a way to do this?

This function simply returns the COM port for use in creating an arduino object.

Here is my code:

function port = ports()
%% Description
%   Searches for the COM Port that the arduino is connected to.
%

%% Try Block
ports = seriallist();

for i = 1:length(ports)
    try
        a = arduino(ports{i});
        clear a
        port = ports{i};
    catch 
        clear a
    end
end

end

Answer 1

[Walter Roberson]

>> try; arduino("/dev/cu.Bluetooth-Incoming-Port"); catch ME; disp('nan nan nah'); end
nan nan nah

The particular exception is 'MATLAB:hwsdk:general:invalidPort' and arduino() without any arguments can also generate 'MATLAB:hwsdk:general:boardNotDetected'