[C320-list] How to get Raymarine Auto Helm to talk to a Garmin Chartplotter

[Jack Fitzgibbon]

On our C320(#441) we have a Garmin GPS Map 740 wired to both the ST 4000 AutoHelm Control unit and a Uniden 525 VHF DSC radio via NMEA 0183 connection points on each unit.  The AutoHelm can utilize Track mode but is electrically powered on its own circuit and not networked with the ST 50 Wind, Depth and Speed instruments so Wind Trim mode is unavailable.

Jack F.


Sent from my iPad

> On Oct 6, 2019, at 5:07 PM, Scott Thompson <surprise at thompson87.com> wrote:
> 
> The control head on the older Raymarine autopilots also have NMEA input connections on the back. So the connection does not necessarily have to be using SeaTalk. At one point (before I replaced all my electronics) I tied these out to a jack on the back of the Navpod where the autopilot controller was mounted. I then made up a cable to connect my handheld Garmin GPS to the autopilot, through this jack, permitting it to go into Track mode on a course defined by waypoints. The handheld sat in a cradle on top of the binnacle guard above the instruments. My rather distant recollection is that I had to connect 12v power, ground, and the two NMEA signal pins, so this wasn't very complicated. The cable was one that I purchased from Garmin that already had the connector for the GPS, so making the cable was simply a matter of putting the right terminators at the other end.
> 
> Perhaps you can do something similar with your Garmin if it supports the older NMEA standard.
> 
>> On 10/1/2019 12:05 PM, Charles Martin wrote:
>> Has anyone tried to connect the standard Raymarine Auto Helm (uses SeaTalk
>> comm) that was factory installed in C320's to communicate with a Garmin
>> Chartplotter?  If so, did you use some sort of cross-talk adapter?
>> 
>> Best,
>> Chip Martin
>> *Bonaventure*, Sail # 767
>> (410) 231-0199
>> chiprmartin at gmail.com