I've posted some simple code at https://github.com/BravoPapa/OmegaGPIO on GitHub.

@chris-mccaslin Thanks for the suggestion. I wasn't able to install that library, but that may be because I'm not familiar enough with Linux to understand what it needs. I did figure out how to access the ports through the filesystem (/sys/class/gpio). If nothing else gets posted before I get my code packaged nicely, I'll post it for others.

@Lazar-Demin Thanks! I'm not that far along with my project, so it's definitely not too late for me.

Yes, use a pull-up or pull-down if it is an input that's not being actively driven. Floating inputs can go either way, and they can definitely cause problems.

I'd recommend using a pull-up resistor and connecting the switch to ground. A capacitor across the switch will add some analog debounce as well. Using a pull-down instead will probably work, but the logic transition levels typically work better with a pull-up, perhaps .1 uF or 1 uF.

As for Kit's question, I think that means that the GPIOs have a 200k pull-up and pull-down resistance, and you need something smaller for a pull-up or pull-down to prevent the input from floating.

Take a look at the ctypes library for Python. It allows you to call C library functions. It seems like it will work, but I'm waiting for some hardware before I can actually write and test any code. Once I get something working, I'll post it on Github.

https://docs.python.org/2/library/ctypes.html

I've been storing programs in /root. It's not read-only (at least not on mine).

@Uwe-Stahl209 I'm too new to Python and the Omega to add interrupts to my code. I'm not sure that Python can handle interrupts directly, but I could be wrong.

I've posted some simple code at https://github.com/BravoPapa/OmegaGPIO on GitHub.

I found a datasheet for the AR9331. The specs on the GPIO are lacking detail, but I did find the following:

VOH = 2.44 V
VOL = 0.1 V
VIH = 0.7 V
VIL = 0.3 V
(These are min/max values as appropriate.)

I'm not finding a maximum voltage for the GPIO pins. The datasheet I found is a preliminary from December 2010. I'm hoping a newer datasheet is available that has more complete electrical info.

Thanks for posting your code. That helped me figure out how to access GPIO via Python.

@chris-mccaslin Thanks for the suggestion. I wasn't able to install that library, but that may be because I'm not familiar enough with Linux to understand what it needs. I did figure out how to access the ports through the filesystem (/sys/class/gpio). If nothing else gets posted before I get my code packaged nicely, I'll post it for others.