How do I pass sensor Data to a GUI?

Hello,

I have recently been using matlab to interact with my arduino. Now I have i down pretty well in terms of creating arduino objects. including libraries and plotting them.

However, my problem lies in passing these arguments to a GUI. to clarify a bit more, I would like to create a simple GUI that plots (or shows in a gauge) the speed of a dc motor. I know I should use a ValueChangingFcn in the appdesigner and well... I get pretty lost. I'm familiar with making something simple, such as a plot that changes color when a drop down menu specifies a certain color. I just cannot seem to figure out using real time data in the GUI.

Please and thanks to whoever reads this.