CONTINUOUSWAVE

I am trying to get an idea if I can connect my Garmin GPS to my SmartCraft gauges (NMEA 0183) for the speedometer to work. Just starting out, and I found my GPS book (Attachment 1), but the SmartCraft has no info on wiring. Wondered if anyone might be of help here. Attachment 2 is what I found in Google Images.

Thank you,

Mike

Also found this about SmartCraft Speedometer.

M

NMEA-0183 signals do not have polarity, and there are no (+) or (-) signals. NMEA-0183 signals are TALKER and LISTENER, and the pairs are designated A and B.

It looks like both manufacturers have ignored the signal name convention, causing confusion, misleading the user, and making the interconnection more difficult than necessary to accomplish. This is common in marine electronics.

Generally a marking of (+) is interpreted at A; a marking of (-) is interpreted as B. A marking of GRD is interpreted as neither A or B but just ground.

Figure out which wires from the GPS receiver are a NMEA-0183 TALKER A and TALKER B.

Figure out which wire from the Smartcraft instrument are a NMEA-0183 LISTENER A and LISTENER B.

Then interconnect them according to the three rules I give in my article on NMEA-0183 connections.

RULE 1: LISTENER connects to the TALKER of the other device with the same A/B notation.

RULE 2: If a LISTENER B has no corresponding TALKER B signal, that LISTENER B connects to ground or the power source common (i.e., negative battery bus in most boats).

RULE 3: If a TALKER B has no corresponding LISTENER B, that TALKER B is insulated and left unconnected.

See more details in

NMEA-0183 Interface Data Collection
http://continuouswave.com/forum/viewtopic.php?f=9&t=816

My guess about the GARMIN device signals:

TAKER A = BLUE
TALKER B = not provided

My guess about the Smartcraft device signals:

LISTENER A = WHITE
LISTENER B = BLUE