Raymarine RL80C with NMEA GPS receiver

[bobs]

Hello gents,

We all know a raymarine GPS receiver , seatalk connectable, is an expencive neccesary gadget right.
Therefor I was wondering if it's possible to use a normal usb GPS receiver , cut the usb thing off en use a few of the 6 internal wires ,
-one like this-

http://www.uploadarchief.net/files/d...c00408-800.jpg

and connect it to a RL80C plus radar/chartplotter unit by using of the NMEA input.
-This is the raymarine connection cable and 5 NMEA leads (the thick red and black are power supply for the unit) -

http://www.uploadarchief.net/files/d...c00411-800.jpg

400$ question is , what usb receiver lwires goes to what raymarine NMEA wires ?


Raymarine colours :
(infolabel on the cable)


orange= plus channel 1
yellow= minus channel 1
green= plus channel 2
blue = minus channel 2
bare wire = ground

USB receiver colours

red = ?
black = ?
yellow = not connected in the USB port
green = ?
blue = not connected in the USB port
white = ?

Tricky question is it not.

Thanks and regards.

[bruadair]

I can't help you with the wiring of the usb gps antenna to you Raymarine unit, but one concern does come to mind. USB devices are typically powered at 3 to 5 volts dc. If you supply power from your ship's 12vdc system will you blow the antenna or will you need a resistor to reduce the power from 12vdc to the appropriate vdc?

More to think about


D & D
s/v Bruadair
The Adventures of s/v Bruadair

[Paul L]

A USB device conforms to the USB spec, not the NMEA spec. You need a GPS device that has a NMEA output. Look at the low-cost Garmins, they normally have a NMEA output port that is configurable through the step up menu.

Paul L

[EngNate]

NMEA is the data protocol, the connection specifications (for a generic GPS) is RS-232 (old) or RS-422 (new & usually backward-compatible). These are serial data connections, as is SeaTalk. Seatalk is compatible with NMEA serial devices, with one distinction: Seatalk is bi-directional - it sends and recieves data on one wire. You can connect either Tx or Rx data to/from an NMEA device directly - Data Rx or Tx to Yellow. With an adapter from Raymarine you can connect both Tx and Rx data.

The RL80C has NMEA inputs and outputs, so just use that. You'll have to go into the installation setup to select the correct position data source.

[Paul L]

NMEA specs both the data protocol and the media interface - rs-422 as you mentioned. The original poster showed a picture of a GPS device that appeared to only have a USB interface. This ain't gonna work.

Paul L

[bobs]

suppose i supply a separate 3,5 volt to the haicom GPS receiver (this is approx. the usb volts) , which wire , TX or RX do i need to connect to the NMEA input of the chartplotter ?

Thanks again

[EngNate]

I convert USB outputs from a PC to serial for connection to an autopilot, no problem, but must use an active converter (w/software) so the computer can recognize the device on the USB bus. The actual data is not changed. You can buy cheap USB to serial and USB to PS2 adapters, but they usually don't work for the above reason. The USB GPS runs on 5V, and the connection diagram is here:

USB pinout and signals @ pinouts.ru

On the Raymarine. Orange is Rx Data +, Yel is Rx Data -

To upload settings or firmware updates to the GPS, you'll need to connect it to a PC.

If you haven't bought the GPS already, I'd suggest the Garmin GP-17N instead.

[Paul L]

You may be able to use a USB to serial converter. You cannot take the pinout listed above and use the data lines of the USB connector directly. These are not rs-422. It will be a lot easier to just get a GPS with a true NMEA output.

Paul L

[fairbank56]

Originally Posted by EngNate

Seatalk is compatible with NMEA serial devices, with one distinction: Seatalk is bi-directional - it sends and recieves data on one wire. You can connect either Tx or Rx data to/from an NMEA device directly - Data Rx or Tx to Yellow.

Seatalk is a RayMarine proprietary protocol used between SeaTalk devices. It is not compatible with NMEA. You cannot simply connect them together. The SeaTalk data must be converted to the NMEA protocol before connecting to the NMEA device. There are devices available that will do the conversion known as a SeaTalk-NMEA bridge.

Eric

[bobs]

Thanks a lot guys.
Apparently it's not as easy as i thought (hoped) it would be.
Maybe i'll give it a try anyway and keep my fingers crossed not to blow up the chartplotter.

Kind regards

[GordMay]

SeaTalk Technical Reference ~ by Thomas Knauf

”SeaTalk is a simple interface for networking Raymarine/Autohelm marine equipment so that all devices of a ship can exchange and share their data. SeaTalk is a proprietary solution of Autohelm and not compatible with NMEA or CAN. Unfortunately Raymarine keeps the technical details of SeaTalk secret. To assist users who want to develop hard- or software to connect their devices to the SeaTalk bus these pages uncover some of the mysteries. Part 3 adds hints how to interface SeaTalk with a PC. The information is unsupported by Raymarine and was found by watching the bits travelling on the bus. Therefore the description is incomplete inaccurate and may even be wrong. Corrections and contributions are welcome.”

Goto: Thomas Knauf ****SeaTalk Technical Reference

Raymarine SeaTalk to NMEA Support: SeaTalk, hsb2 and NMEA Support - Raymarine