[MinnowBoard] Echo to MinnowBoardMax GPIO export fails

[John Hawley]

Ok I spent a little bit of time digging into this, it *LOOKS* like
Ubuntu is offset by +256 vs. stock and/or Fedora kernels.  Not 100% sure
why yet.

That being said I wrote up a quick script that should discover the right
values for everything and output it to a text console:

https://github.com/warthog9/minnow-max-extras/blob/master/lse/what_gpio_num.sh

and I've got a merge request in with it (I'll let Darren have a look at
it and yell at me about it before it gets merged).

If you are having problems, can you run that script and let me know if
the output is right for you?  In the meantime I'll try and dig into why
the offset.

- John 'Warthog9' Hawley

On 01/07/2015 06:51 AM, Michael Jones wrote:
> Martin,
> 
> Very helpful, thanks. I had to think a bit to understand the base of 82 and 154.
> 
> For others:
> 
> For 8x, Code GPIO# = 338 + Linux GPIO# (Chart) - 82
> For 2x, Code GPIO# = 410 + Linux GPIO# (Chart) - 154
> 
> So for the two examples:
> 
> 338 + 84 - 82 = 340
> 
> and
> 
> 410 + 208 - 154 = 464
> 
> I’ll give this a try later this week. 
> 
> Are there any proper ways to expose the /sys paths for user mode like one can do for /dev/ttyN? Or do people just run their code as root?
> 
> Mike
> 
> 
> On Jan 5, 2015, at 7:29 AM, Martin Oldfield <elinux-mbmx-2014-11 at mjoldfield.com> wrote:
> 
>> I've also found wildly different GPIO numbers on my Minnowboard Max.
>>
>> You can read about it at
>> http://www.mjoldfield.com/atelier/2014/12/mbmx-gpio.html.
>>
>>
>>
>> --
>> View this message in context: http://minnowboard.57273.x6.nabble.com/MinnowBoard-Echo-to-MinnowBoardMax-GPIO-export-fails-tp903p907.html
>> Sent from the MinnowBoard mailing list archive at Nabble.com.
>> _______________________________________________
>> elinux-MinnowBoard mailing list
>> elinux-MinnowBoard at lists.elinux.org
>> http://lists.elinux.org/mailman/listinfo/elinux-minnowboard
> 
> 
> _______________________________________________
> elinux-MinnowBoard mailing list
> elinux-MinnowBoard at lists.elinux.org
> http://lists.elinux.org/mailman/listinfo/elinux-minnowboard
>