I presently use my old GT-11 as a USB GPS receiver plugged into navigation software via the USB port. I now want to capture the NMEA output hardwired directly into the NMEA input of my instruments by cutting off the large USB plug from a cable and wiring the appropriate terminals. Does anybody have the USB pinout for the NMNEA out. There are 5 wires, #1 black (presumable case/shield ground), #2 black (presumably -ve ) #3 green, #4 white and #5 red (presumably +5volt). Can anybody advise which are NMEA out. I presume #2 black is NMEA -ve. and either #3 or #4 +ve out?

I would try Locosys direct
www.locosystech.com/en/page/contact-info.html

lmgtfy.com/?q=mini+usb+pinout

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frant said...

I presently use my old GT-11 as a USB GPS receiver plugged into navigation software via the USB port. I now want to capture the NMEA output hardwired directly into the NMEA input of my instruments by cutting off the large USB plug from a cable and wiring the appropriate terminals. Does anybody have the USB pinout for the NMNEA out. There are 5 wires, #1 black (presumable case/shield ground), #2 black (presumably -ve ) #3 green, #4 white and #5 red (presumably +5volt). Can anybody advise which are NMEA out. I presume #2 black is NMEA -ve. and either #3 or #4 +ve out?

I don't know if I am understanding this quite right, but from what you have said, it sounds like you want to use NMEA for other navigation instruments. Is that correct?

"NMEA" in your context probably uses RS232 (aka serial) between devices.

The GT-11 and other devices like it have a USB to serial converter inside the device itself, even though the internal data may yet use a serial stream. The device appears on a USB equipped computer as a virtual serial port, and its over this virtual serial port that the NMEA data is sent.

You can't just take the USB interface and use it to send raw NMEA data. There is a lot more to it.

Possibly, the GPS chip inside the GT11 has the serial NMEA stream available, but even then it will be at TTL levels. You would be better off just buying a GPS that already does send NMEA over serial.

In fact, the Foretrex 101 (and the 201?) have a mini phono connector that sends out straight RS232, and will plug straight into a PC. When you configure the right settings it sends out NMEA. I think the default is 4800 bps.

Did I understand what you are trying to do?


Edit: I just took a look at devices on ebay and it looks like they sell GPS modules that send out TTL NMEA data, but they send it out using a mini-USB connector. I hate it when people do that and use a standard connector for a non-standard interface. In this case, they are sending out RS422/232 out via the mini USB connector, but in no way is this compatible with a PC as it is. You would need to wire this to a serial port instead, BUT as its TTL you would need a RS232/422 to TTL adapter. (A MAX232 would work if you know what that is.)

These devices appear to be cheap at $15, so they may be more appropriate for what you are trying to do.

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FormulaNova said...

frant said...

I presently use my old GT-11 as a USB GPS receiver plugged into navigation software via the USB port. I now want to capture the NMEA output hardwired directly into the NMEA input of my instruments by cutting off the large USB plug from a cable and wiring the appropriate terminals. Does anybody have the USB pinout for the NMNEA out. There are 5 wires, #1 black (presumable case/shield ground), #2 black (presumably -ve ) #3 green, #4 white and #5 red (presumably +5volt). Can anybody advise which are NMEA out. I presume #2 black is NMEA -ve. and either #3 or #4 +ve out?

I don't know if I am understanding this quite right, but from what you have said, it sounds like you want to use NMEA for other navigation instruments. Is that correct?

"NMEA" in your context probably uses RS232 (aka serial) between devices.

The GT-11 and other devices like it have a USB to serial converter inside the device itself, even though the internal data may yet use a serial stream. The device appears on a USB equipped computer as a virtual serial port, and its over this virtual serial port that the NMEA data is sent.

You can't just take the USB interface and use it to send raw NMEA data. There is a lot more to it.

Possibly, the GPS chip inside the GT11 has the serial NMEA stream available, but even then it will be at TTL levels. You would be better off just buying a GPS that already does send NMEA over serial.

In fact, the Foretrex 101 (and the 201?) have a mini phono connector that sends out straight RS232, and will plug straight into a PC. When you configure the right settings it sends out NMEA. I think the default is 4800 bps.

Did I understand what you are trying to do?


Edit: I just took a look at devices on ebay and it looks like they sell GPS modules that send out TTL NMEA data, but they send it out using a mini-USB connector. I hate it when people do that and use a standard connector for a non-standard interface. In this case, they are sending out RS422/232 out via the mini USB connector, but in no way is this compatible with a PC as it is. You would need to wire this to a serial port instead, BUT as its TTL you would need a RS232/422 to TTL adapter. (A MAX232 would work if you know what that is.)

These devices appear to be cheap at $15, so they may be more appropriate for what you are trying to do.

Now you have opened up yourself to a can of worms!!! I have got a lot more questions and you appear as though you may be able to answer some of them.
On the boat I run a mini AT computer that I built to run from the 12volt ships power supply. This machine has 6 physical USB ports and runs Windows7. Two of the USB ports hidden behind the front cover are used for the wireless keyboard/and the other for WiFi dongle.
Boat has Ockam sailing instruments which run from a propriety computer which runs Basic programs loaded onto an SD card. Output to the instrument displays via BNC cable on Ockam bus. This device has an Ethernet cable output and also NMEA output via RS232 which I input into the PC Ockamsoft program with a RS232 to USB converter cable. Also at present input the NMEA via USB from the GT-11 into Ockamsoft. Thats 2 of the remaining 4 USB ports occupied. NMEA output from Ockamsoft sends out to UDP virtual ports(whatever that means).
Also have a Raymarine E80 chartplotters networked via proprietary Raymarine protocol to each other,the Radar scanner,Raymarine GPS device and compass transducer. The NMEA output from Raymarine was connected to the NMEA GPS input of the Ockam computer. However have never been able to get the GPS data on the Ockam computer to work, hence my desire to test an alternative NMEA source as input (the original question).
I run three navigation software packages on the boat PC. #1 is MaxSea plotter with Cmap world charts. We (my electronics guru mate and I) could only get this version of MaxSea to run in a Windows XP environment and therefore run MaxSea on a virtual machine. A second GT-11 hooks into the virtual machine via the next physical USB port (5of6).
#2 is PC Plotter ( a navionics charts) based plotter ie compatible with the Raymarine also functions as the AIS display inputting NMEA AIS and GPS info via USB port #6of6. However need to use a USB security key to launch PCplotter so juggling starts.
#3 Expedition software is used for weather routing and performance analysis. No USB ports left so have to borrow one of the GT-11 USB from either Ockamsoft or MaxSea. \
However Ockamsoft can output both the instrument data and GPS data via virtual UDP ports. That is where I am totally lost. What is a virtual UDP port and how do I set them up, particularly across into the virtual machine. It would be a great advantage to have the instrument data available inside all of the navigation software.
Once that is done I need to send the Ockamsoft info via UDP ports over the WiFi to handheld devices in the cockpit.
To further complicate matters I have an Inmarsat fleetbroadband telephone/broadband connection which hooks up to the computer via an Ethernet cable. This is physically unplugged and a Netgear WiFi router plugged in place to network to laptop and handheld devices. Can I connect the Inmarsdat device via the router? Also when I use the internet via a Telstra broadband dongle the network connection doesn't operate if the Netgear network is connected. Why is this so.
Also my GT-31 fell into the bilge with a USB cable plugged in (trapdoor open) and got some water inside. Repairable?

Frant, please start using the return key sometimes.

It sounds like you are running out of USB ports. Buy a USB hub. Almost all USB devices will handle being plugged into a hub, and its usually the devices that draw a lot of power from the USB bus that have problems.

A virtual UDP port sounds like its just a network (UDP) port, that sends the NMEA data out on the network. There is probably some configuration detail with the IP address and UDP port number for this.

What needs to listen to this data? I think I need to draw a map to try and figure out what you are trying to do.

When you plug internet routers or modems into a network, they generally want to own the network and act as the default gateway (to get to the internet). If two routers are on the same network, and they have the same address, they will complain.

It sounds like you have a few ways of accessing the internet! Some WIFI routers can have an ethernet connection to connect to the internet, with a 3G dongle for connection using Telstra or someone else. I would need to know exactly what the devices are that you are using.

If you want a decent answer, you are going to have to draw me a diagram showing what connects to what and what you need to talk with.

Fixed
use
of
return
key[}:)]
However it is sticky and doesn't always work.
Have got a USB hub but abandoned using it because it wasn't 100% reliable at sea, ie often had frozen or conflicting GPS data.
Have a few ways of connecting to the internet. The satellite broadband service at $16 Mbyte needs to be absolutely sure that you don't get Windows update lurking in the background somewhere downloading hundreds of megabytes. Probably best to leave that connection as a standalone service via the Ethernet cable.
Other internet connections are via WiFi hotspots using the front panel mounted WiFi dongle.
Then there are 3G prepaid USB dongles. (Telstra, NZ telecom,Verizon and Virgin USA). Usually uninstall the driver software for all except the one in current use.
The Netgear WiFi router has provision for Ethernet cable connection to a modem for internet. How do you connect the USB 3G device?
How does the IP address system work?
Will draw a diagram of the system and post a copy. It will probably help to enlighten me to think about what I will draw.

You can get, or at least, used to be able to get, wifi routers that had an ethernet connection for an ADSL modem or whatever, and a USB slot for a 3G modem. I have one here somewhere that I bought because it was cheap and I needed to use it as an ethernet switch.

Have you got any spare PCI slots? You could install a USB card into that if you do, so that you don't need to have an external hub. Some motherboards also have additional USB ports, but you need to bring them out on an additional plate. Some motherboards have them, some don't.

If you have to use a USB hub, can you use it for the keyboard and other stuff, and dedicate a port for the each GPS?

Which IP address system? The one for the wifi router, something else, or in general?


I might have to look to see if I have some older Cisco ADSL routers around here. They can be used to router between ethernets. This can be useful to filter traffic so that you only see web traffic and email, which makes a difference for an expensive service.