Garmin GPSMAP 76CS interfacing to Garmin Fishfinder 250C

[simonfuller]

Help!

I am trying to interface my Garmin GPSMAP 76CS with a Garmin Fishfinder 250C using NMEA (I am using NMEA and not the Garmin protocol as I also wish to add my Icom IC-M421 to the mix once I have these first two working).

I have bought a power/data cable with bare wires for the GPS and have connected them to the fishfinder as described in the manual for the fishfinder.

Blue (Data Out) from fishfinder to Data IN on the GPS
Brown (Data In) from fishfinder to Data OUT on the GPS
Both negative cables for both devices are connected on the same negative bus.

I have enabled the NMEA In/NMEA Out on the GPS (and can see the data coming out of the GPS when I use my PC serial cable and hyperterminal). I have also turned NMEA to 'on' on the fishfinder.

Has anyone been sucessful in connecting these two devices?
Does anyone know what the connections should be, I have trawled through other threads but have been unable to find anyone else so far trying to connect these two devices.

Any help would be greatly appreciated.
Simon

[jwalker]

Not these two units but I have the Garmin 2010 connected to a 150 blue and it works fine. However, does the 76cs have multiple ports? The 2010 does and the sounder input is expected on port 2. Grey out and violet in.

[simonfuller]

Originally Posted by jwalker

Not these two units but I have the Garmin 2010 connected to a 150 blue and it works fine. However, does the 76cs have multiple ports? The 2010 does and the sounder input is expected on port 2. Grey out and violet in.

I believe it only has a single port, the power/data cable has 4 wires:

+VE
GND
NMEA IN
NMEA OUT

There are also no options in the software I can find mentioning different ports which I have read about people mentioning in other places on this forum.

[DJL]

Hi Simon, small world. Where you working these days?

I’ve got my Garmin GPSMAP 182C and Garmin 100 Blue FF talking to each other.

To ask a stupid question, you have selected the data fields you want to be shown on the opposite device?

Also it’s worth noting that as far as I’m aware the Garmin GPS units don't send any NMEA data in simulation mode (I guess it stops DSC radios sending simulated data), so you can only test with the GPS working normally.

[simonfuller]

Originally Posted by DJL

Hi Simon, small world. Where you working these days?

I’ve got my Garmin GPSMAP 182C and Garmin 100 Blue FF talking to each other.

To ask a stupid question, you have selected the data fields you want to be shown on the opposite device?

Also it’s worth noting that as far as I’m aware the Garmin GPS units don't send any NMEA data in simulation mode (I guess it stops DSC radios sending simulated data), so you can only test with the GPS working normally.

Hi Daniel, good to hear from you, long time no see! Working at City of London Freemen's School in Ashtead at the moment (when I don't have my head stuck into the console of my RIB ). What are you upto now? Uni? Work?

On the Fishfinder I have added the "position" field to the display, which in simulation mode displays a simulated lat & long but just goes blank when its in normal mode which i'm guessing when it starts to get nmea data will be automatically populated?

My GPS seemed to send data whilst in simulated mode while it was connected to my laptop via the serial cable, but thats not how i've been testing it as i'm able to get a good lock whilst in my garage.

Regards, Simon

[simonfuller]

Well, I've made some progress, I now have the Fishfinder outputting data to the GPS and being recieved succesfully, however I'm still unable to get anything out of the GPS to the fishfinder or my Icom M421...

How annoying!

[CJL]

Hi Simon,

If your gonna come on this Fireworks Trip on the 5th I'll try and sort it out for you.

Check that the wiring is OK and then its just a matter of the correct setting on the Garmin. The ICOM wont need any playing with.

Chris L.

[simonfuller]

Finally working, after many emails backwards and forwards to Garmin it turns out that there are a faulty batch of Garmin 76CS's out their which are faulty in how the output NMEA data.

Returned my unit to Garmin, for a replacement under warranty, about 5 days later a brand new unit arrived, including a new unlock code for my bluecharts and its all working correctly at last

[CJL]

any news on the throttle box?
C

[jwalker]

Originally Posted by simonfuller

Finally working, after many emails backwards and forwards to Garmin it turns out that there are a faulty batch of Garmin 76CS's out their which are faulty in how the output NMEA data.

Good result, Simon.

It is poor though that the manufacturers get things wrong so often. Not just Garmin.