Garmin 128 connection to PC

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Elemental

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Does anyone know how I can connect my Garmin GPS 128 to a PC for uploading/downloading waypoints etc. The manual describes the data connection but references only Ground, NMEA in, NMEA out and Alarm lines. Presumably the GPS 128 doubles the NMEA lines when in upload mode? A wiring diagram or detailed instructions would be appreciated.

Mark
 
Garmin 128 to PC wiring

green is data in to the GPS
white is data out from the GPS
black is ground

If you have a serial RS232 connection to your laptop (this is likely to be a 9-pin male connector) you need to buy or find lying around** a serial cable that fits this plug. Hack it in half and using a multi-meter identify the wires that correspond to pins 3, 2 & 5. These are likely to be (faintly) marked on the plug or there is a
picture here .

NB this is a view of the BACK of the plug.

Unplug the connector from the GPS and
This is an extract from a Garmin PDF. (Can't remember where I got it, but the title is 'Garmin GPS to PC wiring instructions' if you want to try Googling). It worked for me (although I crimp rather thand solder):


Solder the green from the gps to the wire that goes to pin 3
the white to pin 2
the black to pin 5

Insulate the conections.

Check the gps is set to transmit the protocol your software expects.
Plug it all in and go.


If your laptop has only USB and no serial connection you need to buy a usb/serial converter, then plug the cable you have just made into this.

You do not need to connect green to pin 3 if you don't want your PC to talk to
your GPS, but you might as well as its useful to upload waypoints etc.
 
Perfect response - thank you.

The green/white are documented as 'no connection' in the Garmin Manual - I did wonder what they were for.

Thanks again.

Mark
 
You may need to check your settings deep in the menus - I wasted a Sunday afternoon troubleshooting until I got the 128 sending and receiving the right messages.
 
Garmin 128 GPS Connection to Notebook Computer

I show my hookup at:

http://carlten.tripod.com/Navigation/navigation.html

It helps to use a terminal strip for making connections.
Remember the old serial mouse used on the early computers?
I used the cable from one by just cutting off the mouse.
It plugs in to the 9-pin serial connector on the computer.

I use Fugawi ENC navigation application. It has the Garmin protocol
for uploading waypoints into the Garmin 128. However, not all navigation
applications incorporate the Garmin protocol, which is not NMEA 0183.

Of course the output from the Garmin 128 is NMEA 0183. It also works with the Autohelm ST4000 autopilot. Note that I have installed a selector switch so that I can drive the autopilot from either the Garmin 128 or the Fugawi ENC navigation application in the notebook computer. Works great for the longer route legs.

QE Too
 
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