Wayne.B wrote:
On Thu, 1 Feb 2007 18:48:55 -0500, "Roger Long"
wrote:

Never mind. I found a list at:

http://aprs.gids.nl/nmea/#allgp

I'd still be interested in hearing about anyone's experience with such a
hook up.

Most auto pilots want to know cross track error ($GPXTE), course over
ground ($GPVTG) and bearing to mark ($GPBWC).

I read throug the Garmin manual online and can't find any mention of
cross track error. I'd call Garmin tech support.

GPRMB is what most autopilots use. It gives destination waypoint,
originating waypoint, VMG to waypoint and XTE
$GPRMB,A,0.66,L,003,004,4917.24,N,12309.57,W,001.3 ,052.5,000.5,V*0B

A Data status A = OK, V = warning
0.66,L Cross-track error, steer Left to correct
003 Origin waypoint ID
004 Destination waypoint ID
4917.24,N Destination waypoint latitude 49 deg. 17.24 min. N
12309.57,W Destination waypoint longitude 123 deg. 09.57 min. W
001.3 Range to destination, nautical miles
052.5 Bearing to destination
000.5 Velocity towards destination, knots
V Arrival alarm A = arrived, V = not arrived