From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-f171.google.com (mail-we0-f171.google.com [74.125.82.171]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id D012F20024C for ; Mon, 12 Mar 2012 15:59:42 -0700 (PDT) Received: by werm1 with SMTP id m1so6504090wer.16 for ; Mon, 12 Mar 2012 15:59:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=MWuJAQzzV8CRfhbayBf9bUcxr8jk2ORtDkW5mOJHat8=; b=iSX70anBqoUMltyBBKK+rhdjpAgWFJ++p+WeUsTrdQTz0kudwxRrKaIJxzSncXLluO dacmfN0cHaIyLSDyWUJnv1puZ42P+8LcKR29uj/ZHJLV/9M8JFjpkY2b7uuakIiUY0n5 p4NgTIC67LRW5sSRoim6N09NPVa2Gw8w17Qzu96nM1oxp9ZdjQQkZK9zPvz1AhlnTRvK XbUNxplXQhAsoxAbVq42ZyodlGOgOTn06LDGnY+cIeF9tOw8SeOj0yAv4HGRI402oQI7 ttLeH7WtFfmwob+Y85hOiDHA7Rh5KVGFMlWeY3UuyrtOoJYJ+93EmBWQ9lDeWuEJvNCY ixiA== MIME-Version: 1.0 Received: by 10.180.98.8 with SMTP id ee8mr1838498wib.14.1331593180304; Mon, 12 Mar 2012 15:59:40 -0700 (PDT) Received: by 10.223.151.8 with HTTP; Mon, 12 Mar 2012 15:59:40 -0700 (PDT) In-Reply-To: <20120312220623.GB18256@thyrsus.com> References: <20120312220623.GB18256@thyrsus.com> Date: Mon, 12 Mar 2012 15:59:40 -0700 Message-ID: From: Dave Taht To: esr@thyrsus.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: thumbgps-devel@lists.bufferbloat.net Subject: Re: [Thumbgps-devel] the serial alternative/radio noise X-BeenThere: thumbgps-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 Mar 2012 22:59:43 -0000 On Mon, Mar 12, 2012 at 3:06 PM, Eric S. Raymond wrote: > Dave Taht : >> I AM curious if there is one of the gps boards we've looked at than >> can 'just fit' on this header. Or, for that matter, a RTC. > > How often do I have to sing the "this kind of customization won't scale" > song? Cats, herding. I note that in the early stages of any project, I tend to appreciate all sorts of blue-sky thinking, rather than tie down to any one goal, and try to encourage such in others. I guess in part what drives me in suggesting alternatives (and please note my alternative above was intended as a lead-in into the noise question more than an actual suggestion), is that I would like to find markets for a 'new device', that 'does new stuff', that justifies the manufacturing run, more than a 'usb gps with hyper-accurate pps and time output' may, as a differentiator. To give an example I've long had an interest in climate change, in particular, in the lack of good data from equatorial zones. I had intended while I was still working on my mesh project in Nicaragua to co-locate weather stations with at least some nodes, (multiple open source and open hardware alternatives are available, google for them), and in that case - given that the network might be down or non-existent, having good time for the samples also seemed good (as well as a good location indicator! See http://www.teklibre.com/~d/b4barrios10.kml for an interactive map of the sites I'd surveyed with my handheld gps below san juan del sur, Nicaragua). http://oscirrus.see-do.org/schematics/schematics.html for one weather station (this isn't the one I was thinking of at the time, tho) Anyway, this is a potential market use-case for the hardware as discussed thus far. There are no doubt others. > >> Now, I actually brought this up because in looking at this I realized >> anew what a huge radiator of various forms of electronic noise this >> is. - 2.4ghz and 5.x ghz radios, and a variety of possible waveforms >> from the cpu - and I'm curious as to what extent gps is affected by >> these frequencies. > > You and I have observational evidence that it's not an issue even for > low-end, poorly-shielded hardware, I have observational evidence that we have problems with many kinds of hardware and the cause is undefined, and varies by manufacturer. > -- > =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0Eric= S. Raymond --=20 Dave T=E4ht SKYPE: davetaht US Tel: 1-239-829-5608 http://www.bufferbloat.net