laptop as a gpswith nmea output

[hugues1811]

i have a bu-353 gps antena on my laptop and run opencpn, work great. How can i send gps nmea sentence on a serial port (usb to serial converter) for the repeater in the cokpit or other component on the boat need this info ?

[Lake-Effect]

First of all, I would caution you that making the BU-353 the only GPS source, and the laptop the central distribution point, means that you're utterly dependent on the laptop being up and working to feed GPS data to the other devices, which is bad design. A better way is to have an independent source of GPS data that feeds other devices, INCLUDING the laptop... For example, get a US Globalsat MR350P which has NMEA0183 serial out, and use it to feed everything, including your laptop via a serial-to-USB adaptor ($3 on ebay). Or use a MR350P for the 'boat' and continue to use the BU-353 for the laptop, which gives you independence and you have a back-up GPS.

To do it as you have asked, you'd need the serial-to-USB adaptor, and some software to do the 'sharing'. Linux has gpsd and other utilities for routing the data. I don't know an equivalent for Windows but a quick Google brought up this, which looks interesting.

[muttnik]

Originally Posted by hugues1811

i have a bu-353 gps antena on my laptop and run opencpn, work great. How can i send gps nmea sentence on a serial port (usb to serial converter) for the repeater in the cokpit or other component on the boat need this info ?

Check out the opencpn manual section on data connections
I haven't personally tried (Hopefully someone will be along shortly who has) but plug in your output usb to serial converter, bring up the toolbox, select the connections tab, add a serial connection for that device (at whatever baud your repeater is, probably 4800) and make sure you check the "output on this port" box down the bottom (that's the critical bit). If you've got AIS data coming into opencpn and your repeater is 4800 baud, you'll need to filter the AIS out, but you don't mention that so hopefully you're fine.

On the serial side, tx to nmea in + on the repeater, gnd to nmea in - (or gnd if it's an old single ended one).

As Lake-Effect said, having to have the laptop on all the time is a bit of a bind. A BU-355 isn't expensive and has serial output. You could consider getting one of those and mounting it somewhere permanently to give you a bit of GPS redundancy

[hugues1811]

Thanks a lot, i upgrade open cpn to 3-2-2 to have the connection tab, set up com five as the receiver of the bu 355, set up com 3 where is my usb to serial conveter and unable "output on this port, and everything work great. I have now my laptop like a gps with an output in nmea. That's in case of my garmin gps breakdown, i can use my pc and opencpn and connect it to the rest of the equipment needs nmea gps sentences (autoplilot, repeater, etc)