On Dec 17 21:18, Andrew McMillan wrote: > On Mon, 2007-12-17 at 00:10 +0100, Andreas Putzo wrote: > > On Dec 14 20:19, Andrew McMillan wrote: > > > > > GPSDrive is not displaying any altitude reading from my GPS (a Garmin > > > > > 60CSx). If I telnet to the gpsd port on my local machine I definitely > > > > > do see my altitude coming through on the various data streams > > > > > available. > > > > > > The GPS itself is a Garmin GPSMap 60 CSx which has a barometric > > > altimeter, can see 10 satellites at the time and is itself displaying > > > altitude and '3D' in it's own status. > > > > > > Here is a sample from connecting to gpsd now. > > > > There are no GSA sentences in your sample log and i think gpsdrive > > heavily relies on them to determine whether it knows the altitude or > > not. > > According to the manual of the 60CSx the device should use GSA. > > Did you set the Serial Data Format in the Interface Setup menu to NMEA > > and if not, can you please verify if the problem persists with this > > setting? > > I can set the serial data format to 'NMEA', but it doesn't make a > difference because I'm using the USB connection. It looks like the > Garmin will only output in the 'Garmin' format via the USB connection, > so gpsdrive is depending on the 'on the fly' translation done by gpsd > for non-NMEA units. > > On the other hand, gpsd is certainly *providing* the altitude within the > NMEA output, viz: > > $GPGGA,055148,4106.5421,S,17452.2917,E,1,09,,94.9,M,16.836,M,,*42
> It looks like the GSA sentence is not produced by gpsd when it's doing > it's on-the-fly translation. It does provide a 'q' command which returns > essentially the same data, so it could probably be added. > > On the other hand, perhaps using the GSA message as the sole source of > altitude data seems short-sighted, especially if there are GPS out there > which can provide greater altitude accuracy by combining the GPS data > with other sensors internally. > > I've filed bug #456634 against gpsd asking if it can also provide GSA > sentences when synthesizing NMEA output, but I think it would still be > nice if gpsdrive were capable of using the GGA output as an alternative > as well. IMHO gpsdrive shouldn't try to parse raw gps data itself altogether :) There was a DBUS interface to gpsd which should work with garmin but it is currently broken. Anyway, i will talk with upstream about this. Regards, Andreas
