Arduino Issue: I cannot run any of my code. 'To create a new connection, clear the existing object.'

I have only just begun to learn how to work with arduinos in matlab. My code will not run past the third line, so here are the first few lines:

clearvars
clear all
ard_UltraS('COM4', 'Mega2560','Libraries','Ultrasonic') = arduino;

Matlab gives an error at the third line:

"MATLAB connection to Mega2560 at COM4 exists in your workspace. To create a new connection, clear the existing object."

I have tried clear all, clearvars, clearing that specific variable, restarting matlab, restarting my computer, and different USB ports. With each of these attempts i get the same error. Is there anything to clear the variable I haven't tried? or some way to make sure that the arduino is disconnected?

[Rohan Kale]

Hi William,

The construct of the syntax "ard_UltraS('COM4', 'Mega2560','Libraries','Ultrasonic') = arduino;" is not supported for creating an arduino object.

Please use the following syntax instead:

>> ard_UltraS = arduino('COM4', 'Mega2560','Libraries','Ultrasonic');
or
>> ard_UltraS = arduino;

Refer to the MATLAB documentation page on creating an arduino object.

Hope it helps.

Answer 1

[Arun Kumar]

Hi Willian,

Please refer the following page for correct syntax of the command.

https://www.mathworks.com/help/supportpkg/arduinoio/ref/arduino.html

Hope this helps!

-Arun