From: Landon C. <gu...@36...> - 2006-07-28 02:27:15
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Hi Dave, Thanks for your thoughts on the topic. I got the impression from the Wiki that there was an already trodden technique for doing this. The wiki at: http://docwiki.gumstix.org/Frequently_asked_questions/ GPSstix_and_Audiostix2#How_fast_should_a_satellite_be_tracked_using_GPSs tix.3F says: "If the GPS serial port is redirected to the outside world, download a copy of u-blox's u-center 4.01 GPS Evaluation Software from here and run it on a Windows PC. From u-center, access all the available NMEA and UBX messages and their contents, including complete status on all the internals of the receiver (most of the detailed stuff is only available over the UBX protocol). If not using u-center, then read the protocol doc and hack manually" It was stated so matter of fact that it seemed like I was missing something major if I didn't know how to do that already. I was thinking of something even more mundane such as writing a simple app that bridged ttyS2 to Bluetooth (serial or TCP) so it would act a little like a serial to ethernet converter (except serial to BT/TCP) or serial to Bluetooth serial bridge. Don't know if it's as simple as passing data back and forth or if there's a more hardware protocol and driver work involved to make it work seamlessly to fake out the ublox u-center diagnostics. My particular configuration is a basix 400 w/BT and GPSstix. That's all that's in the stack right now. On Jul 27, 2006, at 5:58 PM, Dave Hylands wrote: > Hi Landon, > >> I've also asked Don to help track down some answers to these >> questions including the redirect of the serial to use the u-blox >> diagnostic software from a serial stream out of the gumstix. The >> Wiki refers to this technique but doesn't say how it's done. > > So, just to be clear about what you're trying to do here. > > You want to take the serial data from the GPSstix (which is on ttyS2) > and get it to a PC? Yes, but bi-directionally so it fakes out u-center to make it think it's talking directly to the GPS. > > 2 - I'd be happy to modify sertest.c into a loopback program > > 3 - You could also use the same loopback program and use the usb > serial gadget. These both sound promising as well. I'm thinking about writing a gumstix service that would be a TCP server for clients over BT or Ethernet. It would provide a 1-way data stream of NMEA data to clients who connected to the gumstix - BT running in access point mode with TCP/BT. That way, more than one client could have access to the GPS data through the gumstix. Perhaps that same software could work bidirectionally (for only one client to be able to write to the GPS.) That's solving a different problem. I use a Mac OS X serial port app called PortTerm which can act as a TCP server and pipes all serial data in/out of that if it's running. It's very handy for sharing the serial port with more than one client (usually for purposes of logging.) Guess we won't know if u-center will work with any of these ideas until we try. Will try to get some time this weekend to look further at this. Thanks again for your thoughts on the topic. Landon |