From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.182.29.196 with SMTP id m4mr4320811obh.26.1391720997612; Thu, 06 Feb 2014 13:09:57 -0800 (PST) X-Received: by 10.140.26.243 with SMTP id 106mr52516qgv.31.1391720997584; Thu, 06 Feb 2014 13:09:57 -0800 (PST) Path: border1.nntp.dca.giganews.com!nntp.giganews.com!uq10no10251289igb.0!news-out.google.com!y18ni4938qap.1!nntp.google.com!f11no13211100qae.1!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Thu, 6 Feb 2014 13:09:57 -0800 (PST) In-Reply-To: <1lg4oeejbp1e5$.h5mrspzez74h$.dlg@40tude.net> Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=189.77.226.1; posting-account=TRgI1QoAAABSsYi-ox3Pi6N-JEKKU0cu NNTP-Posting-Host: 189.77.226.1 References: <5e8fad3a-94e6-4517-af54-db8b4146803e@googlegroups.com> <858uto3cj3.fsf@stephe-leake.org> <1lg4oeejbp1e5$.h5mrspzez74h$.dlg@40tude.net> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <1979d60e-99b3-4706-a308-aebf5a3e9cd9@googlegroups.com> Subject: Re: Raspberry Pi, Real-Time and Ada From: "Rego, P." Injection-Date: Thu, 06 Feb 2014 21:09:57 +0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Xref: number.nntp.dca.giganews.com comp.lang.ada:184689 Date: 2014-02-06T13:09:57-08:00 List-Id: Hello Dmitry, On Thursday, February 6, 2014 5:44:03 AM UTC-3, Dmitry A. Kazakov 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 ho= w > many AD/DA converters are physically present (to be shared between analog= ue > inputs). > Note that if you have, say, one AD multiplexed to four inputs, then no > matter how RT your OS is, the latency between 1st and 4th inputs will be = no > less than 4 conversion times. Taking typical values 40us * 4 =3D 0.8ms. N= ow > if inputs considered synchronous, this is also the jitter. Ok. > BTW, many boards do not even have all GPIO pins soldered. You should chec= k > if Raspberry Pi has ones you wanted to use. Yes, that's a point. Yesterday I found out that it does not have. I needed = to use some PWM outputs, but RPi only exposes one, so I will have to use so= me timers for emulating the others, which is not very precise, but at this = point I don't need much accuracy. Thanks.