Re: [Gumstix-users] Fast GPIO

[Dave H. <dhy...@gm...>]

Hi Matthew,

On Mon, Oct 11, 2010 at 1:46 AM, Matthew Lai <cyb...@we...> wrote:
> Hello,
>
> Is the /sys/class/gpio interface the only way to access GPIO from userspace?
>
> I wrote a shell script that just writes "1" and "0" to
> /sys/class/gpio/gpio144/value as fast as possible.
>
> And I measured 2.5kHz on my oscilloscope.
>
> I'm planning to do some bit banging with those GPIO pins, but that may
> be a little too slow.
>
> Is there a way to toggle the pin faster?

You can try my GPIO driver.
<http://www.gumstix.net/wiki/index.php?title=User_GPIO_Driver>
but don't use the gpio program, write your own.

An even faster method is to mmap in the I/O space for the gpio
registers themselves.

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.DaveHylands.com/