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 42F5020024C for ; Tue, 13 Mar 2012 06:23:23 -0700 (PDT) Received: by werm1 with SMTP id m1so844224wer.16 for ; Tue, 13 Mar 2012 06:23:21 -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=voeahKGrDIux7FShDbNczt0PwvXZ+pPXST8eVcdIzSc=; b=pH2xTxLe6E9X7lFMzFJghuyngPB6VjmIYPyLgVqs//yOphqCd+cHy0PZpVN0Snyjjp iAF7JtAUf0RnFh6XsF2Er6tuoQXDUTvqeQFeEPMZlEg4wHCoSNVzdbB7tQripkqA7B2b 96ONnCCsLnRYF2ghBtzhp/U329ug8Dbg2uVb/fNAGAwlEtNyipiyTDw24eW4e08OhNlT hlnOTk6n76rYJ+OWawdrdM61TZbX3tbFGvjrhpeZauXWWWlRkMliMXJMMjB7isn1t2ea BF/gFP/F9P3sK/y/yLguivF0Fx+1fJzBT5x8OnZsAo4EFsV6ZBHfaMNoG0lRpxnmovt1 GMdA== MIME-Version: 1.0 Received: by 10.180.106.9 with SMTP id gq9mr7430248wib.17.1331645001252; Tue, 13 Mar 2012 06:23:21 -0700 (PDT) Received: by 10.223.151.8 with HTTP; Tue, 13 Mar 2012 06:23:21 -0700 (PDT) In-Reply-To: <20120313045408.GB19984@thyrsus.com> References: <20120312212608.GC17895@thyrsus.com> <20120312213946.GE17895@thyrsus.com> <20120312224546.GA18404@thyrsus.com> <20120313014341.GC18695@thyrsus.com> <20120313021325.GA19502@thyrsus.com> <20120313045408.GB19984@thyrsus.com> Date: Tue, 13 Mar 2012 13:23:21 +0000 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] Build vs. modify vs. what should we be doing anyway? 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: Tue, 13 Mar 2012 13:23:23 -0000 On Tue, Mar 13, 2012 at 4:54 AM, Eric S. Raymond wrote: > Dave Taht : >> On Mon, Mar 12, 2012 at 7:13 PM, Eric S. Raymond wrote= : >> > Chris Kuethe : >> >> ublox antaris4 (and probably everything newer) has on-die usb and >> >> implements the abstract modem class. but 1PPS isn't transmitted over >> >> usb. >> > >> > Annoyingly, it probably could be. =A0That modem model pretty much has = to have >> > DCD and RI events. >> >> Perhaps simply a real usb microcontroller with spi or i2c then driving >> usb-2.0 for real... > > So, how would we get the data off the GPS chip if not through the TTL-lev= el > serial interface? =A0Are you proposing building our own serial-to-USB ada= ptor > with a microcontroller? Proposing, not as yet. Researching the idea, yes. 1) It would be my hope that the blox UBX-G6010-ST-TM actually did supply the PPS over it's existing USB interface. The specs are otherwise quite ideal - single satellite operation, fixed location operation, 15ns pulse, etc., as you'll see from the links provided earlier. eval board here: http://www.abacuscity.ch/abashop?s=3D142&p=3Dproductdetail&sku=3D114 But I figure an email or conversation with u-blox is in order regarding the level of their pps support and firmware. If portions of their firmware were hackable, that would be excell= ent. 2) If it didn't, interfacing the time pulse pin of nearly any hardware with a microcontroller that that had a full usb stack (eg the AVR mentioned earlier) offers the opportunity to offer gps over a non-serial, saner-for-gps new usb interface, no need to emulate rs-232... This latter idea has some good points (not all that much more expensive than a usb-serial chip!), and bad (whole other cpu, when there's a perfectly good arm7 inside most of these gps chips) > -- > =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