nmea o183 to laptop open cpn

[Captain-Hook]

So I have a simple question. I have 3 seperate streams of nmea 0183 data I want to SIMPLY send to my opencpn laptop without buying a multiplexer, trying to learn LInux prog. etc. can I run cheap db9 usb converters into a usb hub and 1 line to my laptop? Avoiding ground loops by using the ! wire rs232 common ground option. Data Points* pre 2015gx2150 ais. pre 1995? st60 depth pre 2015 garmin echomap 54 dv or backup raym. A65 plotter pre-many moons? if not, i assume it would work if i used 3 seperate ports on laptop. have 2 usb, 1 ethernet 1 hdmi. win 10.i am no techie of any kind. Thanks for any patientce exercised.

[barcoMeCasa]

Originally Posted by Captain-Hook

So I have a simple question. I have 3 seperate streams of nmea 0183 data I want to SIMPLY send to my opencpn laptop without buying a multiplexer, trying to learn LInux prog. etc. can I run cheap db9 usb converters into a usb hub and 1 line to my laptop? Avoiding ground loops by using the ! wire rs232 common ground option. Data Points* pre 2015gx2150 ais. pre 1995? st60 depth pre 2015 garmin echomap 54 dv or backup raym. A65 plotter pre-many moons? if not, i assume it would work if i used 3 seperate ports on laptop. have 2 usb, 1 ethernet 1 hdmi. win 10.i am no techie of any kind. Thanks for any patientce exercised.

Signalk can do that, download link is bottom right under "releases".
https://github.com/SignalK/signalk-server-windows

Then create connections for each of the usb/serial adaptors, nmea coming in automatically gets multiplexed & sent out again as TCP on port 10110, Opencpn get's it all from there >


The signalk connections setup is similar to opencpn >


There's usually some FUD (fear, uncertainty & doubt) about how complex & difficult signalk is spread about by a few on the web (it's not unless you really go deep) , maybe just keep an open mind and give it a go

[thomm225]

I ran mine in through an RS 485 USB Adapter. I think it was $5.00 or so.

I use it to bring in AIS and GPS from my SH 2200 VHF Radio. (1 port)

I don't use Signal K.

The adapter works with my RPI 4's (Linus) or my Windows Toshiba Laptop. (Windows 10)

Which ever computer I use I just redo the connections on OpenCPN and I'm good.

Video is with an RPI 4.

https://www.youtube.com/watch?v=-TOdSCDHb2s

[barcoMeCasa]

Oops..
Been using signalk for so long and it can do so much completely forgot opencpn will happily multiplex the data coming in, just add more connections

[cas206]

I think these responses miss the point that OP has 3 serial devices and only 2 USB ports. OP was looking to add a USB hub between the PC and the 3 devices. I don't know if that's possible.

[wholybee]

Originally Posted by Captain-Hook

So I have a simple question. I have 3 seperate streams of nmea 0183 data I want to SIMPLY send to my opencpn laptop without buying a multiplexer, trying to learn LInux prog. etc. can I run cheap db9 usb converters into a usb hub and 1 line to my laptop? Avoiding ground loops by using the ! wire rs232 common ground option. Data Points* pre 2015gx2150 ais. pre 1995? st60 depth pre 2015 garmin echomap 54 dv or backup raym. A65 plotter pre-many moons? if not, i assume it would work if i used 3 seperate ports on laptop. have 2 usb, 1 ethernet 1 hdmi. win 10.i am no techie of any kind. Thanks for any patientce exercised.

Yes, you can use a USB hub. Usually NMEA0183 is RS422, not RS232, so be sure to buy the correct adapters. The Garmin Echomap might be RS232. So double check that. I would guess you need 2 RS422 and 1 RS232 for the Garmin.

Do not connect grounds together, consider each connection separate. Especially with RS422, connecting them together will break things so they don't work.

[cas206]

Ok, I have two GPS pucks. They have USB connections, but connect as serial devices. Basically, the serial to USB conversion is built in. I connected both to a USB 3.0 hub and then connected the hub to my Linux PC. Both devices showed up as separate serial ports (/dev/ttyUSB0 and /dev/ttyUSB1). I "assume" if I had a third it would also work. So that indicates that what you want to do could work.

The potential problem is that a pure wire conversion (really cheap converter) depends on a software driver on the PC to do the conversion. Sending these serial signals through a hub may not work. I don't have anything to test that scenario with.


For the GPS pucks, and better serial to USB converters, there are electronic bits that convert the signal to USB before it even reaches the PC and so not requiring a software driver to work. So the hub sees USB data, not serial signals. That's your best bet.

[wholybee]

Originally Posted by cas206

Ok, I have two GPS pucks. They have USB connections, but connect as serial devices. Basically, the serial to USB conversion is built in. I connected both to a USB 3.0 hub and then connected the hub to my Linux PC. Both devices showed up as separate serial ports (/dev/ttyUSB0 and /dev/ttyUSB1). I "assume" if I had a third it would also work. So that indicates that what you want to do could work.

The potential problem is that a pure wire conversion (really cheap converter) depends on a software driver on the PC to do the conversion. Sending these serial signals through a hub may not work. I don't have anything to test that scenario with.


For the GPS pucks, and better serial to USB converters, there are electronic bits that convert the signal to USB before it even reaches the PC and so not requiring a software driver to work. So the hub sees USB data, not serial signals. That's your best bet.

All of the converters work the same way. Your GPS probably has the same chip in it as a serial to USB converter. That is why it shows up as a serial port. The RS232 and RS422 even use the same chip, but the other electrics in the device are different. Most converters use a chip manufactured by Prolific or FTDI. I prefer FTDI because it "remembers" the com port that is created. With Prolific, if you unplug it and plug it in again, you sometimes get a different port created. Often you don't know what you get when you buy one, but I always look for FTDI.

There are no "pure wire" converters. The signaling is completely different and that is impossible. There is no way to do the conversion in software. They all require drivers, but mostly the drivers are included with the OS now so you don't usually need to install them separately. Sometimes (usually with fake knockoffs of the FTDI or Prolific chips) you do need to install something.

Adding a USB hub doesn't really change anything. You computer has a HUB built into the motherboard, that is how you get multiple USB ports. So even without a hub, you actually are going through a hub. With a HUB, you are going through 2 of them.

The most important part Captain-Hook needs to know is to get the correct (RS-232 vs RS-422) adapters. Connecting RS-232 and RS-422 together is possible, but it gets tricky and is not intuitive or the way that seems it should work.

[Tupaia]

You could use a std RS232 - USB converter for one and a Dual R232 - USB converter for the other 2

https://www.microconnectors.com/usb-...erial-adapter/