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From: Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP>
Newsgroups: comp.lang.ada
Subject: Re: Raspberry Pi, Real-Time and Ada
Date: Thu, 6 Feb 2014 13:16:40 +0000 (UTC)
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Date: 2014-02-06T13:16:40+00:00
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On 2014-02-06, Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote:
>
> Last time I checked there were ARM GPIO drivers for Linux, so I see no
> problem with RT except for possibly poor performance of the GPIO.
>
> It really depends rather on the hardware than the OS. In particular on how
> many AD/DA converters are physically present (to be shared between analogue
> inputs).
>

Oh, Dmitry, not this again. :-)

You may live in a analogue world, but for many (most ?) people, their
GPIO lines are used in a mainly digital mode with little A/D conversion
involved.

For myself, I do the odd A/D conversion on a GPIO line, but the vast
majority of the time they are used in a pure binary 0/1 digital mode.

I've seen a number of reports about how much overhead there is within
Linux when trying to drive the GPIO lines on the Raspberry Pi, so I can
easily believe that it _is_ a OS level issue.

Simon.

-- 
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world