I am having problems getting GPS data from a Garmin Etrex into my dataPlus application.

I can successfully get the GPS data into DataPlus on my Allegro using GPS expansion pod (com 3) and using a Holux GPS receiver on COM 1 but it does not appear to work with the Garmin receiver (on COM 1)

With the Etrex, I can see the data streaming in using ALT T (and not all of the NMEA sentences are showing) but the data does not show in the sensor data box and it will not capture the position.

Any suggestions?

Simon (Waiotahi)

​Typically, the advanced serial parameters for the column receiving the data is configured to only consider valid lines those which start with a particular word, such as $GPGGA. If you have that qualifier in there, can you make sure that the Garmin is outputting an NMEA string with that qualifier at the appropriate position of its output (for instance, beginning at character position 0, the beginning of the line)?

The reason I suggest this is because you indicate that you can see data coming in but it’s never stored in the column. This usually happens when the appropriate NMEA sentence isn’t getting output or it is beginning with something other than $GPGGA (for example).

Mike Duppong
Forum Moderator
Electronic Data Solutions


I haven’t revisited this problem since your last reply but I have looked to see if the Garmin is generating the correct qualifier and it is.

Last week I had another DataPlus user ask me if I had managed to bring the Garmin data into DataPlus as they were experiencing the same problem.

Do you have any other suggestions? and could you please confirm that you have managed to communicate with Etrex successfully.



We have not tested with any Garmin units, however if you’re seeing the data streaming in with the ALT+T terminal mode, I think half the battle is won. This means the serial port parameters (baud rate, parity, etc. are correct).

You say that not all of the NMEA sentences are showing, but you also indicate that you checked to see if the Garmin was generating the correct qualifier and it is, so I will assume that is not the problem.

If you look at the string coming in, can you count the elements that are separated by commas and verify that the position data you wish to grab is in the correct location of the string?

For example:


If your position data is in element ‘b’, you would tell DataPlus to use element 2 (element 0 is the qualifier, a=1, b=2, c=3).

Also, what do you have for an input line terminator? Typically it is ^M (a carriage return).

Mike Duppong
Forum Moderator
Electronic Data Solutions