I'm crew on a boat (wooden 8.5m from 1973) which has a GPS and a tiller pilot that seem to work fine separately, but don't seem to want to talk to one-another. My captain is adamant this combination "used to work, but is not working now"; I myself have never attempted to use the autopilot, nor seen it in use.
The GPS is a Garmin GPSMap 182C which talks NMEA 0183 v3.0; According to its documentation, it sends "GPRMC, GPGGA, GPGSA, GPGSV, GPGLL, GPBOD, GPRTE, and GPWPL (as well as PGRME, PGRMZ, and PSLIB)".
The pilot is a Tillerpilot TP32 which also talks NMEA 0183. According to its documentation, it accepts "APA, APB, RMA, RMB, RMC, BWR, BWC, VHW, XTE (as well as VWR and MWV)".
As you'll notice, these abbreviations are helpfully incomparable, and I haven't become wiser by studying references.
The wiring connections I have all quadruple-checked; the only thing I cannot check is the actual data content of the NMEA signal data. I have also triple-checked that the NMEA settings are sane (GPS Port 1 out: NMEA v3, 4800 baud; GPS Port 2 out: None; and yes it's port 1 that's connected through to the tiller pilot's socket). I have been unable to determine the baud rate of the Tillerpilot, and the parity settings of both devices, but I must assume they are set to a common standard.
So my questions are:
- Are these two devices, in fact, compatible?
- If they are, what more can I check?
If necessary please advice in comments for the following:
- Should I post this else instead, and if so - where?? (There seems to be no good fit for questions of an nautical-electrical nature. I posted to Meta, which suggested either Outdoors or Electrical; the latter just closed my 1st try as off topic so I'm also trying here.)
- Are there any better tags for this question here?