Originally Posted by tominny
I should clarify that I don't want to use the GPSmap 78 for location information into OpenCPN, I want to use OpenCPN to create a route
and then load it to the 78, instead of having to enter waypoints manually. This has worked very well for me with the 76 model (until that one died of salt water
I think all the advice to get serial adapters and serial cables
is wrong, since all you want to do is transfer routes. Try this before spending your time and money
trying to downgrade from USB:
Within OpenCPN, export the desired routes in a .gpx file. From this point forward, OpenCPN will not have anything to do with the transfer. I've never been able to get OpenCPN to directly read/write routes to my Garmin Oregon
, so I rely on other software
tools to transfer the .gpx file to the Oregon
Mount the GPS
as a mass storage device. Just plug
it into the USB port with a USB cable. At this point, my Oregon gives me a selection between Mass Storage mode and GPS mode. Your device may do it differently, but there MUST be a way to get the device recognized as an ordinary external storage device. That's the first step, because any software
you run can then read/write the files in storage.
Once that part is done, the rest is a little tricky. Unfortunately, just copying the .gpx file over does not work. The device needs it to be put into a special temp file, and upon rebooting the device, it reads the new routes into the current
.gpx file. For that, you need computer software.
The easiest and most reliable way to do this is to buy Garmin's HomePort software, and use it to copy routes over to the device. If you don't want to spend money
, you can try the Garmin MapSource software. It's been discontinued and is a little less straightforward than HomePort, but you can legally download free copies of an upgrade installer, and there are some tricks to get the upgrade installer to do a clean install. Use Google
to learn how.
Prior to that I used g7toWin free utility to make the transfers, but it was very unpredictable, and it has been so long since I did that, I don't even know whether it's compatible with Win7 or Win8.
If you wanted to use your GPS to feed real-time NMEA data to OpenCPN, you would need software to create the virtual COM port. Garmin used to distribute "Spanner" for this. I don't know what they use now for the newer operating systems.