Re: Ada / Automation fellows

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Sat, 28 Mar 2015 11:52:19 +0000, Simon Wright wrote:

> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
> 
>> A short question. How do you access GPIO on Raspberry Pi? Over the text
>> file devices?
>>
>> We access GPIO, analogue inputs and PWM output through text files. It looks
>> crazy to me. Is there a better way?
> 
> Is this through the /proc filesystem?

Through the device tree /sys/class/gpio/.../value contains '0' + LF + EOF
or '1' + LF + EOF. And needs lseek each time when read again.

> It goes against the grain, but it
> does hide the gruesomeness of an ioctl-based interface; and not really
> further removed from reality than presenting GPIO as a character
> device.

Strangle kind of reality where digital input is character...

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de