I've got a Delorme tripmate connected to a pl2303 usb-to-serial adapter. If I do "sudo echo "ASTRAL" >> /dev/ttyUSB0 && gpsdrive", with gpsdrive configured for 4800 baud rate and serial connection, without gpsd running, I can get gpsdrive to work (ASTRAL is required to "wake" the gps). However, I haven't been able to get gpsd to work yet. No matter what I do, what order I do what (ASTRAL then gpsd, vice versa, start gpsd then plug in the gps, etc), gpsdrive always gives me a timeout recieving data from the gps. I've tried both gpsd from the ubuntu repos and comiling it myself (because I wasn't sure if Tripmate support was included with the ubuntu version), with the same results, both being v2.33. I've read in a few places about a command line parameter (-T t) to enable tripmate support in gpsd, but when trying to use it, gpsd tells me it's an invalid option. Also, I can't find this (or any other mention of tripmate) in the gpsd docs, except for the fact that it's supported.

I'm very much a newbie when it comes to communicating with serial port devices, especially under linux. for all I know, this could all be because I don't have gpsd starting with 4800 baud rate, but frankly, I can't find where it says how to do such a thing. Also, if I run "cat /dev/ttyUSB0" and then start gpsd, I get all sorts of random characters, mostly questions marks with inverted colors and lower case x. Thanks for any help.

I've always had to explicitly tell gpsd where my device was. When you start gpsd with the device already connected, are you using the -f switch?

Try gpsd -f /dev/ttyWhatever

Also, recent versions of gpsdrive can use the serial directly without gpsd... which it sounds like you've had success with. So why the need for gpsd?

from what I've gathered in the man pages, the -f switch is depreciated (if this is incorrect, please let me know). And yes I've been using "gpsd /dev/ttyUSB0", without the device gpsd complains that it can't start without a device and immediately exits. As far as using gpsdrive with the serial connection, yes it works, but no it doesn't work perfectly. Gpsdrive often requires restarting several times before it will get data from the gps, takes quite a while to obtain an intial reading (because it won't send an initial location to the gps like gpsd can), and doesn't close cleanly (hangs and requires "killall gpsdrive" or similar). Bugs aside, I'm also looking to try out another gps program, Roadmap, which looks to be somewhat better suited for my needs.

Sorry for the delay...

You're right about the -f switch

Does xgps work after you type gpsd /dev/ttyUSB0 ? Also, after starting (or trying to start) gpsd, do you click start gpsd in gpsdrive? It sounds like gpsd won't start reading the gps until a client requests it for models with a standby mode. Not sure if the -n don't wait feature would be useful.

Another quirk... when I was first setting up the gps on my laptop, I had a lot of problems. I think a lot of it was poor gps reception where I was trying to setup. I changed locations and could troubleshoot much better. Are you trying this all out in an area you get solid reception?

well, in the area where I've been trying it (from my car in the driveway with the gps on the roof) I can get 11-13 satellites with gpsdrive, and it usually gets a reading from about 7 of them. xgps also doesn't work, I don't remember exactly what it says, but something to the effect of no data incoming from the gps. I'll give the -n switch a shot once I get ubuntu back up and running on my laptop, and I'll post back with that result (but atm, I just got back from climbing a mountain, I'm headed to bed). Also, after starting gpsd manually, gpsdrive only offers the option of "stop gpsd", so it does recognize that gpsd is running.

And as for the reply time, don't worry about it, I'm very patient. Hell, I've been playing with this thing for over a year now, trying to get it to work, a couple days won't make a bit of difference.

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