Create VDR text file

[Heida]

Hi guys, I primarily use openCPN and the AIS function at home to monitor ships in my area but since I have no real GPS input I do not get the range to AIS targets. I understand I can" simulate" my current GPS position and thereby get the requested range to AIS targets by sending an NMEA string as a textfile via the VDR plugin, However, I have not found any info on how to write such a file. My position is Lat 57,59662 North and Long 11,94363 East. Can anyone please include this in a text string file that the VDR plugin can read? Much appreciated BR Goran

[rgleason]

You are on the right track. You will have to do some of your own coding in Nmea0183

In the OpenCPN Manual under Advanced, find NMEA0183 and scroll down to GLL Sentence

https://opencpn.org/wiki/dokuwiki/do...tude_longitude

Looking at that, perhaps Eric Raymond's website is better
https://gpsd.gitlab.io/gpsd/NMEA.htm...itudelongitude
Example: $GNGLL,4404.14012,N,12118.85993,W,001037.00,A,A*67

$--GLL,ddmm.mm,a,dddmm.mm,a,hhmmss.ss,a,m*hh

$--GLL,ddmm.mm(Latitiude),N(orS),dddmm.mm(Longitude), E(orW),hhmmss.ss(UTC),A,m*hh(Checksum)

Once you have the sentence worked out, you will need to get the right checksum at the end or OpenCPN will reject it. Use one of the checksum calculators listed

[Hakan]

Hej Heida...
Print a copy of this string in between your VDM messages so often it will be replayed ones every second or so when you have the replay rate at about 10-15%. No problem if you copy to much of them. If you get it to seldom the position will be lost now and then. If so just print in more.



$GPGLL,5735.797,N,01156.617,E,123000.00,A,A*67


A big lake in Skintebo??
Good luck
Håkan

[Heida]

Hi and many thanks , used the string I got from Hakan below and pasted it in a .txt documen in a separate folder among my charts and...wow it works!!