Humminbird Side Imaging Forums

Side Imaging Forums => 798c SI => Topic started by: Bebson on March 27, 2012, 09:02:07 AM

Title: 798si - no gps
Post by: Bebson on March 27, 2012, 09:02:07 AM

It seems I have 798SI with dead internal GPS. It works fine for one day, and then I cant get no GPS fix wor weeks. I checked and soldered all power connections, and problem is still here.

I have two questions. Will external antenna (AS-GR16) help me to get GPS position, or can I somehow get position from my handheld GPS (Garmin 76CSX) . Can I connect my garmin with HHGPS cable and get position?

Sending the unit to repair is not the best solution, couse I live in Europe, and I have USA model of 798SI.

Title: Re: 798si - no gps
Post by: ITGEEK on March 27, 2012, 10:19:33 AM

This is just my guess:
If you have a plug on your machine that will allow hooking up an external
GPS, then I would think that it would work, providing there is a software
selection on your unit between the internal and external gps.

If there is an external GPS plug, I don't see why you couldn't fabricate a connector
coming from your hand held.  You would need to know how to wire it.

Greg would be the authority on this.

Title: Re: 798si - no gps
Post by: Bebson on March 27, 2012, 10:25:24 AM

That is what I am thinking. External GPS port is NMEA port.
Garmin also have 4 pin NMEA port.
I just dont know if I must connect all wires (+12v, -ground, In, Out) or just ground-ground and HBin-GarminOut. Or ground and HBout-GarminIn

I'm waiting for Greg or some other expert to clarify.

Tnx...

Title: Re: 798si - no gps
Post by: ITGEEK on March 27, 2012, 10:57:54 AM

Since your Garmin already has juice to it,
I would think that all you need is the NMEA out on the Garmin to the NMEA pin on the HB.

Title: Re: 798si - no gps
Post by: Humminbird_Greg on March 27, 2012, 11:28:33 AM

Bebson,
Yes the AS-GR16 GPS Receiver will work with your 798ci Si unit.

So will an external NMEA 0183 GPS feed.  I am not familiar enough with the Garmin 76CX to know for sure but I know o many others that have connected Garmin hand held GPS units to our units without problems.  You need their NMEA connection cable and our AS-HHGPS cable for this.  I would only connect their NMEA Output wire to our NMEA Input (Green) wire and tie the ground wires together (Black wire for us).  Make sure that the NMEA output on the Garmin is turned on as well.  The AS-HHGPS cable will come with connection instructions.  I would not connect the (Red) power wire on the AS-HHGPS cable.  If it is connected or allowed to short against something it could cause a failure of some of the internal circuitry of the 798 unit that would make it necessary to send it in to be repaired.

Title: Re: 798si - no gps
Post by: Bebson on March 28, 2012, 06:20:49 AM

Thank you Greg!!! It worked straight away !!!!  ;D

If anybody else wants to connect Garmin to HB, to get fix from garmin, this is simple solution...

Garmin pinout
(http://pinouts.ru/connectors/garmin_4pinround.gif)

(http://www.ve3kbr.com/graphics/garmin_pplug/garmin_connector.jpg)

HB Pinout
(http://i968.photobucket.com/albums/ae164/etruesdale/Hummingbird/AS-HHGPSCableConnections.jpg)

Connect:
HB pin 2 > Garmin pin 3   (HB-black to Garmin-black)
HB pin 5 > Garmin pin 2   (HB-green to Garmin-white)

Turn Garmin on and wait him to get fix, turn HB on, and you should get position !

Title: Re: 798si - no gps
Post by: Bebson on March 28, 2012, 06:30:07 AM

(http://img521.imageshack.us/img521/3200/garminhb.jpg)

Title: Re: 798si - no gps
Post by: sonar2000 on March 28, 2012, 11:18:38 AM

Good work Beb.....

Can you take the pinout pictures and make an entry in the articles and tutorials section on the pinouts.
That way it will be easier for folks to find on a search..

Thanks, Chuck

Title: Re: 798si - no gps
Post by: Bebson on April 06, 2012, 05:13:42 AM

done  ;)

http://forums.sideimagingsoft.com/index.php?topic=3858.0 (http://forums.sideimagingsoft.com/index.php?topic=3858.0)