Moderated Discussion Areas
  ContinuousWave: Small Boat Electrical
  Connecting GPS Receiver to RAYMARINE Autopilot

Post New Topic  Post Reply
search | FAQ | profile | register | author help

Author Topic:   Connecting GPS Receiver to RAYMARINE Autopilot
d norrod posted 02-21-2010 11:17 AM ET (US)   Profile for d norrod   Send Email to d norrod  
I purchased one of RAYMARINE's new Smartpilot X-5 autopilots with the ST70 control head. I ran a cable from my Eagle 500c fish finder to the NMEA input of the course computer and set the Eagle to send [NMEA] signals. But when I try to use the fishing patterns of the autopilot the display comes up as "NO GPS FIX." I have contacted RAYMARINE's customer support of this matter and they had me check several things, such as the voltage from the Eagle which fluctuats between 3.24 and 3.68 volts, what NMEA 0183 version the Eagle putting out (2.0), and [if it] sends GPS signals in GLL sentences. Their last suggeston was to return the unit and have the NMEA input and output ports tested. I am trying to stay away from their last suggestion since I've already sent it back twice in the last year. One was for a recall. Is there any other GPS [receivers] I can buy or possibly borrow to eliminate whether the problem is with the autopilot or the GPS [receiver]. Any suggestion would be of great help.

Thank you,


jimh posted 02-21-2010 12:19 PM ET (US)     Profile for jimh  Send Email to jimh     
In your situation you have two serial data devices, a sender and a listener. You need to make some assessment of which of them is malfunctioning. In order to do this you need to obtain a known-good device that is either a sender or a listener. Substitute the known-good device for its analogous component in your system. The easiest test would be to substitute another device for the listener.

To test the GPS receiver and its NMEA output, you could connect the NMEA-0183 data out signal to the serial port of a computer. Install software on the computer that can monitor a serial port. Connect to the serial port and monitor the data coming from the GPS receiver. The data on the serial port input to the computer should resemble a typical NMEA-0183 datagram.

For details on how to make such a connection and what the data ought to look like, see:

You could also use another device on your boat. My chart plotter has a function that allows you to see the data on its NMEA-0183 input. If your device has such a function you could use it to see the data from your GPS receiver.

SJUAE posted 02-21-2010 02:46 PM ET (US)     Profile for SJUAE  Send Email to SJUAE     
I dont know the difference between the versions but you RAYMARINE's is NMEA 0183 v3.01 and you Eagle is NMEA 0183 version 2.0 compatible.

RAYMARINE's accepted sentances:
APB Cross track error, bearing to waypoint, waypoint number
Bearing to waypoint, distance to waypoint, waypoint number, time
Latitude/longitude, time
MWV Apparent wind angle, apparent wind speed
RMA Course over ground (COG), speed over ground (SOG), latitude/longitude,
RMB Cross track error, bearing to waypoint, distance to waypoint, waypoint
RMC Course over ground (COG), speed over ground (SOG), latitude/longitude,
time, variation
VHW Speed through water, heading
VTG Course over ground (COG), speed over ground (SOG)
XTE Cross track error
ZDA Time, date

Eagle's transmitted sentances:
GLL transmits latitude and longitude of present position, time
of position fix, and status.
• RMC and RMB transmits navigation information messages.
• APB transmits autopilot information.
• GGA transmits time, position, and fix related data.
• GSA and GSV transmits fix mode, DOP values, and satellites in
view information.
• DBT transmits the depth below the transducer.
• DPT transmits the depth
• MTW transmits the water temperature.
• VLW transmits the distance traveled through water as measured
by the paddle wheel.
• VHW transmits the water speed as measured by the paddle

Assuming it should understand some or most of the sentances from your Eagal unit and looking at the manual it seems the baud rate can be changed I would try all to see if it's simply this speed is wrong as RAYMARINE's manual does not specify the input baud rate but would assume it's one of the faster ones eg 19200


SJUAE posted 02-21-2010 02:51 PM ET (US)     Profile for SJUAE  Send Email to SJUAE     
ps: Each of the Eagle output sentances have to be checked on to transmit in the settings configration menu. So double check this to.
jimh posted 02-21-2010 02:52 PM ET (US)     Profile for jimh  Send Email to jimh     
Steve's suggestion about the parameters of the serial connection is very on-point. The autopilot may be set for something different than the usual data rates because it is a real-time system and wants faster data flow.

Post New Topic  Post Reply
Hop to:

Contact Us | RETURN to ContinuousWave Top Page

Powered by: Ultimate Bulletin Board, Freeware Version 2000
Purchase our Licensed Version- which adds many more features!
© Infopop Corporation (formerly Madrona Park, Inc.), 1998 - 2000.