From: Bob Goddard <1963bib@googlemail.com>
Subject: Re: GNATCOLL-Mmap example
Date: Tue, 28 Jan 2020 14:06:28 -0800 (PST)
Date: 2020-01-28T14:06:28-08:00 [thread overview]
Message-ID: <74d98654-5932-4fdb-8b1b-a1378bc3f853@googlegroups.com> (raw)
In-Reply-To: <ec5138af-d91d-4f4c-ad73-d6de2372fe1d@googlegroups.com>
On Tuesday, 28 January 2020 20:18:03 UTC, Philip Munts wrote:
[...]
> Here is a quick example using libsimpleio:
>
> WITH GPIO.libsimpleio;
> WITH RaspberryPi;
>
> PROCEDURE test_gpio IS
>
> outp : CONSTANT GPIO.Pin :=
> GPIO.libsimpleio.Create(RaspberryPi.GPIO18, GPIO.Output);
>
> BEGIN
> LOOP
> outp.Put(True);
> outp.Put(False);
> END LOOP;
> END test_gpio;
>
> On a Raspberry Pi 4, which is what happens to be plugged in today, I measured a 360 kHz square wave at GPIO 18. Never mess around with memory mapped I/O unless you need insanely high performance. Then you would probably want to use DMA anyway.
Think I'll use that as a backup, but go down the ioctl route, it is a learning process after all...
prev parent reply other threads:[~2020-01-28 22:06 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-25 21:52 GNATCOLL-Mmap example Bob Goddard
2020-01-28 2:10 ` Stephen Leake
2020-01-28 5:59 ` J-P. Rosen
2020-01-28 8:25 ` Dmitry A. Kazakov
2020-01-28 18:53 ` Bob Goddard
2020-01-28 20:07 ` Dmitry A. Kazakov
2020-01-28 20:17 ` Bob Goddard
2020-01-29 8:19 ` Dmitry A. Kazakov
2020-01-29 21:56 ` Bob Goddard
2020-01-30 2:45 ` Dennis Lee Bieber
2020-01-31 16:59 ` Björn Lundin
2020-01-28 19:11 ` Philip Munts
2020-01-28 20:15 ` Dmitry A. Kazakov
2020-01-28 20:18 ` Philip Munts
2020-01-28 22:06 ` Bob Goddard [this message]
replies disabled
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox