I am trying to use All Star Link without modifying a cm 108 chip. I am trying to use the GPIO pins on the Odroid U3 expansion I/O board to control the repeater logic signals (COR/PTT) but all I could find was information on using either the GPIO pins on the cm108 fob (which must be modified to use) or using a parallel port. The Odroid U3 doesn't have a parallel port and I think the native GPIO pins should have the capacity to use the COR/PTT signals.
I can't find any information on how to go about using the native GPIO pins on an sbc for All Star Link. Is there a way to do this?
My thoughts on an approach to this:
1. create a driver or port that uses the GPIO pins as a parallel port
2. provide a memory address to the rpt.conf file that has a value corresponding to the GPIO status so that it may be read as a parallel port
3. alter the software to use native GPIO as another option as opposed to parallel port
I am not sure how to approach any of these options. I think option 3 would be best but I don't know how this is possible. May i get some suggestions or help regarding this? Thanks!