How can I connect a device while using the matlab app environment?

Hi, I'm trying to connect an arduino device into matlab. When I write my own personal script, the device() function works fine and I'm able to connect. However when I use a graphical interface through matlabs app generator, I get an error.

Here's my code and my error. Matlab crashes every time after giving this error. As you can see I'm declaring it at startup, meaning that this is the first thing the program initializes.

The code crashes only when I'm running the app environment and I can easily declare the device in a script. Let me know if more information is needed.

Thank you!

[Stephen Johnston]

I have an update, I realized that the GUI doesn't use the base workspace but Evalin does. By using assignin('base', 'oscillator', 1) I'm at least able to make the error go away, but now matlab simply crashes with no error report.

Confusing.

[Subhamoy Saha]

Instead of using global variable try to use app property.

[Adam Danz]

Subhamoy Saha's advice is good.

Don't use a global variable and don't run clear all.

Here's how to declare a variable in your app

https://www.mathworks.com/help/matlab/creating_guis/share-data-across-callbacks-in-app-designer.html

[Rik]

Despite your flag ("Unnecessary comment"), Subhamoy's comment is actually helpful advice. You should try to store your data in app properties, instead of using the base workspace. Using the base workspace is similar to using global variables: you are storing data in a place where every function can access it and change it, which will cause bugs that can be difficult to track down.

[Stephen Johnston]

@Adam Danz

Thank you very much! I wasn't aware that you had to declare the variable differently inside the app environment. My code works now and here's a photo of what it should have looked like.

This saved me a gigantic headache and I very much appreciate it.

[Adam Danz]

Glad I could help clarify things.

@Subhamoy Saha, please copy your comment to the answers section and perhaps expand upon it a bit.