Hello again cg0,
I must add the following: if you need to add any block to the initialization function (called once at the beginning), you can use the standard Simulink block Initialize Function. You can find it by typing "Initialize" in the model, then selecting it, or from the Simulink library browser (slLibraryBrowser) - under Simulink/User-Defined Functions. You can put inside this special subsystem the GPIO output block, with the constant you need to set in the initialization. You can delete the state writer that comes with the standard block.
View from Top model - Initialize subsystem:
View from inside the Initialize subsystem:
Note: You'll most likely have to set "Unspecified initialization detection" to "Simplified" - for the model to build. You will get an error otherwise.
Hope this helps,
You are right, the GPIO blocks do not have the option to set an initial value. If you need this, in our current release you can add a subsystem you call only once in the beginning (controlled by a flag variable) in which you can use the GPO block and set it to the desired value. We'll take this feedback under consideration and we'll most likely add this option in the block itself in our next release (which will come out this summer).
Thank you for sharing your thoughts!