GPIO and MIDI Performance in linux

[newmiracle]

Hi,

I'm interested in buying an A20. The amount of GPIOs makes it perfect for a project I'm trying to realize. I would be using them for input of MIDI messages, output of LEDs, maybe some other ideas..

Linux is going to be necessary for what I am thinking. I wanted to know how GPIO support was for Linux implementations. How fast is it? Is it significantly more difficult than Android? Is there a preferred distro (ie; does the new Ubutntu image handle it better than the standard Debian)? Any quirks, problems, or issues I should be aware of?

Then also, the same questions for MIDI implementation and performance.

Any experiences with doing things like this?

Thanks for any input you may have.

[Tom]

Hi,

If you want to use GPIO, you should consider, that there is no interrupt driven gpios on the a20 at the moment...
Ask XFer here in the forum about midi, he has a running implementation.

Good luck

[newmiracle]

I'm not entirely clear on all of the terminology for embedded/EE stuff. The lack of interrupt driven GPIOs would mean that I would have to be constantly "polling" or "scanning" the inputs programmatically, correct?

[Tom]

I'm not entirely clear on all of the terminology for embedded/EE stuff. The lack of interrupt driven GPIOs would mean that I would have to be constantly "polling" or "scanning" the inputs programmatically, correct?

Yes, you would need to do that. Problem is, that this is a performance killer or you have to live with a delay (and i don't think you want that for midi).
Hope one day the a20 will receive better support.