The NMEA Interconnect project.
The goal here was to connect a GPS plotter, string of ST50 Raymarine instruments, a Raymarine radar, an ICOM SSB and VHF, and anything else that spoke NMEA.
Click on a picture to see a larger copy.
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This is the final board. All the external connections are to the terminal strips. |
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The data flow had to be worked out before anything could start. It was necessary to use an existing NMEA multiplexer because we had it :-) and to get a new one that could handle high speed AIS data. We also had the Seatalk-NMEA interface that helped a lot. |
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The tables below describe each external connection. They reference the diagram to the left |
Connections to/from the NMEA distribution boar on Aurora
All connections labeled with "in" meaning into the board from an instrument.
| TSA | Main GPS connections |
| 1 | – Power for GPS |
| 2 | + " " " |
| 3 | Port 1 in from GPS |
| 4 | Port 1 out to GPS |
| 5 | Port 2 in from GPS (hi speed) |
| 6 | Port 2 out to GPS (hi speed) |
| 7 | Port 3 in |
| 8 | Port 3 out |
| 9 | Port 4 in |
| 10 | Port 4 out |
| 11 | Acc on signal (for GPS 17) |
| 12 | Alarm low from gps |
| TSB | "Instruments" power switch near radar |
| 1 | To Instruments switch |
| 2 | To inst switch (chrome) |
| TSC | Main GPS data out direct from GPS and |
| 1 | + NMEA Out from Actisense MUX |
| 2 | " " (bussed together) |
| 3 | – NMEA out. Max 4 listeners |
| 4 | " " (bussed) |
| 5 | + GPS NMEA nav output |
| 6 | " " (bussed) |
| 7 | – GPS NMEA nav output |
| 8 | " " (bussed; max 3 listeners) |
| TSD | Spare GPS, PC, and AIS |
| 1 | Spare GPS In |
| 2 | Spare GPS out |
| 3 | N/C; ground above signals to another ground like 6 & 7 below |
| 4 | PC In from PC (red) |
| 5 | PC Out to PC (violet) |
| 6 | PC ground (orange) (6 & 7 strapped together for ground) |
| 7 | – AIS in from SR 161 |
| 8 | + AIS in " " |
| TSE | DSC in to Raymarine Mux |
| 1 | + DSC in to Mux port 1 |
| 2 | + DSC in to Mux port 2 |
| 3 | + Any NMEA in to Mux port 3 |
| 4 | – Gnd for inputs to Raymarine mux |
| 5 | - GND from Ray Mux out |
| 6 | + combined out from Ray Mux out |
| TSF | SeaTalk connections |
| 1 | N/C |
| 2 | Seatalk Red |
| 3 | Seatalk White |
| 4 | Seatalk Yellow |
| TSG | Power to board, SeaTalk, and black boxes |
| 1 - 2 | + Board power in (12 VDC) from Newmar Navpac |
| 3 -4 | – Board power in (12 VDC) from Newmar Navpac |
