From martinjonestechnology@googlemail.com Wed Aug 17 13:32:01 2011 Received: from mail-ew0-f44.google.com ([209.85.215.44]) by stoneboat.aleph1.co.uk with esmtps (TLS1.0:RSA_ARCFOUR_SHA1:16) (Exim 4.72) (envelope-from ) id 1QtfHj-0006EA-5v for balloon@balloonboard.org; Wed, 17 Aug 2011 13:32:01 +0100 Received: by ewy19 with SMTP id 19so362210ewy.31 for ; Wed, 17 Aug 2011 05:31:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:subject :content-type:content-transfer-encoding; bh=OSm/FRTnNCrGmlexe0Mt3AIuB16DpD3m5lFQESSQXEs=; b=qG/l6CpLzdSrRnn1y1fo+8pOWG3bRPHkGQTN/CGfTYJVeoFulZb1ADYYB5fkKssz9b Vwld0SuR3N1drehV4PMzCUTuOVi00XIix1JqobDVnX2Ot9elvboBTr3Yn2UQb97EXc51 uNhSMuqzrK6bSOtwrrYXnIkbxYJFTbd7bzRD8= Received: by 10.14.145.143 with SMTP id p15mr236130eej.195.1313584304836; Wed, 17 Aug 2011 05:31:44 -0700 (PDT) Received: from [192.168.1.11] (188-223-88-181.dsl.cnl.uk.net [188.223.88.181]) by mx.google.com with ESMTPS id d44sm582219eeb.56.2011.08.17.05.31.42 (version=SSLv3 cipher=OTHER); Wed, 17 Aug 2011 05:31:43 -0700 (PDT) Sender: Chris Jones Message-ID: <4E4BB4AD.9010402@martin-jones.com> Date: Wed, 17 Aug 2011 13:31:41 +0100 From: Chris Jones User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2.9) Gecko/20100915 Lightning/1.0b2 Thunderbird/3.1.4 MIME-Version: 1.0 To: Balloon Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 209.85.215.44 X-SA-Exim-Mail-From: martinjonestechnology@googlemail.com X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on stoneboat.aleph1.co.uk X-Spam-Level: X-Spam-Status: No, score=-3.1 required=4.5 tests=AWL,BAYES_00,FREEMAIL_FROM, RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.1 X-SA-Exim-Version: 4.2.1 (built Mon, 22 Mar 2010 06:51:10 +0000) X-SA-Exim-Scanned: Yes (on stoneboat.aleph1.co.uk) Subject: [Balloon] I2C troubles on Balloon 3 X-BeenThere: balloon@balloonboard.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Balloon List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Aug 2011 12:32:01 -0000 Hello all, I know some people in the Balloon community have done a lot more work with I2C than I have. I'm now using I2C more intensively and having some problems. It works most of the time but will more or less randomly give up and say, 'i2c-pxa: timeout waiting for bus free'. Adding some debug to the i2c code shows that the PXA's I2C controller is claiming to be busy at these times. Has anyone else seen this? My current theory is that the ratsnest of wires I'm testing with is causing some electrical unpleasantness, which results in a bogus START condition that the PXA's I2C controller is seeing and then waiting ad infinitum for a STOP condition. For now, the problem seems to have gone away after a rearrangement of scope probe earths and things, but I'm not fully confident of having cured it. Chris -- Chris Jones - chris@martin-jones.com Martin-Jones Technology Ltd c/o Element Energy Ltd Twenty Station Road, Cambridge, CB1 2JD, UK Phone +44 (0) 1223 655611 Fax +44 (0) 870 112 3908