Garmin 43CV NMEA0183 to USB

[Spot]

Hello,
I have a Garmin 43CV and want to tie it into OpenCPN.
Would this type of cable/adaptor work?
I am still quite new to all of this and appreciate the input!
Thanks!


FTDI USB-RS232-WE-1800-BT-0.0 CABLE, USB TO RS232 SERIAL, 1.8M, WIRE END


https://www.digikey.com/product-deta...078-ND/2441365

From the Garmin Support Site:
NMEA 0183 Connection Guidelines

When wiring NMEA 0183 devices, follow these guidelines:

• Transmit (Tx) (+) should connect to a receive (Rx) (+)
• Tx (-) should connect to a Rx (-)1
• Rx (+) should connect to a Tx (+)
• Rx (-) should connect to a Tx (-)2

1In the event the sending device has a Tx (-), but there is not a corresponding Rx (-) on the receiving device, leave the sending device's Tx (-) disconnected.Failure to follow this guideline can damage the sending device.
2In the event that the receiving device has a Rx (-), but there is no corresponding Tx (-) on the sending device, bring the Rx (-) to ground.
In general, designated ground wires (Commonly labeled: Common Ground or NMEA Ground) on an NMEA 0183 cable should be connected to a common ground. For specific wiring information, please consult your device's Installation Instructions for the associated wire colors.
Example Interfacing a VHF 110 with echoMAP Plus 44cv

[fgd3]

The cable will certainly transfer serial data to a COM port on a Windows computer via the computer's USB port. If the data connections on your Garmin 43CV are the same as those shown in the drawing for the echoMAP Plus 44cv the connections should be pretty straightforward. Connect the red wire from the Garmin cable to the red wire on the data cable. Connect the black wire from the Garmin cable to the black wire on the data cable. Connect the blue wire from the Garmin cable to the yellow wire on the data cable. Connect the brown wire from the Garmin cable to the orange wire on the data cable. Leave the remaining wires on the data cable disconnected.


Fabbian

[Spot]

Thanks Fabbian.
-So basically make sure TX+ from the Garmin goes to RXD of the cable and similar matching of RX+ to TXD?
-Common ground makes sense.
-Shouldn't the red wire from the Garmin just go to 12v as the red wire from the RS-232 is set to 0V (GND) as a default?
The difference between 43CV and 44CV is the set of maps that come standard with the unit.

[fgd3]

You're right. The red wire from the Garmin cable should be connected to +12V. It should not be connected to any wire on the data cable. The black wire from the Garmin cable should connect to both the black wire on the data cable and -12V. I misread the data sheet for the data cable earlier. I think the connections to +12V and -12V can be omitted if you want to power the 43CV from its internal batteries.


When I made a similar cable for my Garmin GPS 72 (using a USB to RS-232 converter) I included a jack connected to the red and black wires into which I could plug a cable leading to a 12V cigarette lighter plug when I wanted to supply external power to the GPS 72.



Fabbian

[Schnapsy]

@Spot

I have the same cable and it works well.
Only two wires from this cable need to be connected, the yellow and the black.
But you need a driver.

Some informations on these pages (in french)
https://www.schnaps.fr/articles.php?...=311&tconfig=0
and
https://www.schnaps.fr/articles.php?...=311&tconfig=0

You'll find the drivers at this adress
https://www.schnaps.fr/download.php?lng=fr&tconfig=0 (soft divers)

[Spot]

Thanks again Fabbian!
Merci beaucoup Schnapsy!
I will order the cable and report back after the wiring and driver installation.

[Spot]

Yesterday I got the cables soldered and enough of the Garmin unit assembled for testing. I still need to figure out placement of the head unit and transducer on the boat.

This morning I went after the drivers and settings to get things to talk and listen.
I PM'd Schnapsy about the drivers offline, merci beaucoup for the tips!
It looks like Win10 loaded a good FTDI driver set by itself.

I needed to change baud rates on the VCP and in OpenCPN to 38400 and tell the Garmin to output NMEA 0183 High-speed.

After some time of no joy until the above settings were changed...the FTDI cable blinked a happy green and the NMEA debug window started displaying strings faster than I could read them. I went to check GPS positions on the tablet and Garmin and all was in agreement.

Thanks for the tips and tricks!