Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: EATSERVER: mailn 1166; Body=3 Fuz1=3 Fuz2=3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v5HI8K4G028174 for ; Sat, 17 Jun 2017 20:08:21 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1dMI0E-0004hf-49 for rs_out_1@blacksheep.org; Sat, 17 Jun 2017 18:59:18 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1dMI06-0004hW-2s for rsgb_lf_group@blacksheep.org; Sat, 17 Jun 2017 18:59:10 +0100 Received: from porthos.netcom.co.uk ([217.72.171.73]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1dMI02-0001SZ-M5 for rsgb_lf_group@blacksheep.org; Sat, 17 Jun 2017 18:59:08 +0100 X-DKIM-Result: Domain=abelian.org Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=abelian.org ; s=default; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:To:Subject:Sender:Reply-To:Cc: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=UQRmbgCdgbcZOu6+rJIvDj+BLBqofWJa6IkMy1iu9Gw=; b=BD+XzBXddlPYb9gdrEFj5PT6vU /2wqvjdGqoSOzUsBD9rZ/PKuF4/l+5PnyjyXS/UhBIj+C1ALG2XRokBk7ij0Bj4JEge81RLpWA8/b zX2HMKCZQPAg+w0HfRUs2MvJ6s//Ck33V+KgesdHIpbQqUcW3NPruIt+4Htq874/Ghoo=; Received: from i-194-106-52-83.freedom2surf.net ([194.106.52.83]:44998 helo=pn.abelian.org) by porthos.netcom.co.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1dMI01-00053u-4z for rsgb_lf_group@blacksheep.org; Sat, 17 Jun 2017 18:59:05 +0100 Received: from [127.0.0.1] (localhost [127.0.0.1]) by pn.abelian.org (Postfix) with ESMTP id 8C9E540088E for ; Sat, 17 Jun 2017 17:59:04 +0000 (UTC) To: rsgb_lf_group@blacksheep.org References: <15ca21dc75e-1e15-bcda@webprd-m105.mail.aol.com> <0f9558b4-457d-a395-58c9-7f9be3393cdd@sky.com> <4767d79f-2bf6-d838-bfd4-3e78102d6f5d@abelian.org> <510c15eb-b57a-0ebb-9037-1f83e0652cf2@sky.com> <933fcc32-d4c9-10cd-14b4-c179d66e27f9@abelian.org> <7ab80e0f-40d7-6b07-19c1-f4b256d47c52@sky.com> From: Paul Nicholson Message-ID: Date: Sat, 17 Jun 2017 17:59:04 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <7ab80e0f-40d7-6b07-19c1-f4b256d47c52@sky.com> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - porthos.netcom.co.uk X-AntiAbuse: Original Domain - blacksheep.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - abelian.org X-Get-Message-Sender-Via: porthos.netcom.co.uk: authenticated_id: catchall@abelian.org X-Authenticated-Sender: porthos.netcom.co.uk: catchall@abelian.org X-Scan-Signature: 739d4fb39bd02fc5a2de5437a39bb056 Subject: Re: LF: Octo-soundcard for the Raspi Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.75 Status: O X-Status: X-Keywords: X-UID: 12005 > http://abelian.org/vlf/tmp/170617a.gif > Yes that's it! Then there's a high pass getting in the way, must be the input circuit of the Octo. You'll have to use a shorter PPS. 2mS to 5mS ought to do it. > Might be easier to user a stand-alone GPS Yes, Linux can use any GPS for timing, the daemon gpsd can communicate with just about every GPS using either NMEA or native protocols. If you get a GPS with PPS and USB serial, just plug the USB into the RPi and run gpsd and ntpd. gpsd will find the GPS and detect the protocol and get the time from it. ntpd reads the time from gpsd and syncs the system clock. vtcard uses that time to roughly timestamp the sound card data. All you need are a few magic words in /etc/ntp.conf to set it up: server 127.127.28.0 minpoll 4 maxpoll 4 fudge 127.127.28.0 time1 0.051 refid GPS and you can play with the time1 parameter to tweak away the comms latency on the GPS serial data. The nice thing about ublox GPS is that their comms protocol is very well documented and you can adjust things in great detail, firing commands at it via the program gpsctl. -- Paul Nicholson --