From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from snark.thyrsus.com (static-71-162-243-5.phlapa.fios.verizon.net [71.162.243.5]) by huchra.bufferbloat.net (Postfix) with ESMTP id 56816201AC7 for ; Sat, 17 Mar 2012 07:19:13 -0700 (PDT) Received: by snark.thyrsus.com (Postfix, from userid 1000) id 1E54D4081F; Sat, 17 Mar 2012 10:19:11 -0400 (EDT) From: esr@thyrsus.com (Eric S. Raymond) To: thumbgps-devel@lists.bufferbloat.net Message-Id: <20120317141911.1E54D4081F@snark.thyrsus.com> Date: Sat, 17 Mar 2012 10:19:11 -0400 (EDT) Subject: [Thumbgps-devel] Progress in Shenzhen 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: Sat, 17 Mar 2012 14:19:14 -0000 Of the 5 companies I contacted, two - NaviSys and UniTraq - have gotten back to me, confirmed that their USB GPS dongles do not ship 1PPS, and expressed interest in the possibility of customizing a product for us. A third, Xucai Technologies, responded without bringing up the possibility of an OEM/ODM product. This is as good a response rate as I was expecting. Three devices are under discussion. One NaviSys device is the GR-300, bsed on uBlox 6 with integral USB interface. I think this one is actually a non-starter as it would require fiddling with the uBlox firmware to get the chip to ship 1PPS notifications. The other NaviSys device is the GR-300: SiRFIII + PL2303. The UniTraq device is the UD-731R: SkyTraq + CP-2102. Both adapters have full Linux support and have DCD pins. Both chipsets emit 1PPS. Neither device connects the 1PPS pin to the adapter DCD. I am pitching both companies the idea that with one added PCB trace they could sell to a sizeable untapped market of people with applications like network tomography and Stratum 1 NTP servers. I've told them we're willing to help them test and qualify the product if they'll sell the results back to us at a price that is reasonable for a hundred-unit deployment. It's early in the negotiations yet, but things look promising. These outfits are clearly used to doing ODM/OEM business - the only real difficulty I'm having is explaining why I think this mod will work, because these people don't know the odd corners of the USB spec involved. In the process of writing my explanations I've done more research (including reading the Linux PL2303 driver source code and grokking how USB handshake control messages are handled there) and my confidence that the mod actually will work has increased. I think I have at least one more plausible company - GlobalSat - to poke about this if neither NaviSys or UniTraq follows through. More might be findable through alibaba.com -- >>esr>>