December 2, 2012 at 6:26 pm #21043
> Well, actually I am trying to use MATLAB’s GUI interface to control the LEDs.
You did already say that, but it is actually as I was guessing, more or less: It’s not that you’re writing a program that runs on the Arduino, you’re using Matlab’s firmware on the Arduino, which is designed to interface with the Matlab GUI that you run. That firmware parses commands (a fairly limited set of commands) from the computer and then executes the corresponding command on the Arduino itself.
If you want to add a SetPoint function that you can use within MatLab, extend the Matlab firmware by adding the Peggy 2 library to it, and calling the functions that you want to from within that firmware.