EM7565 - Where to start with GNSS?

I have an EM7565 connected to my PC via USB2.0. I installed the GobiSerial and GobiNet drivers for Linux and mobile networking works like a charm. But how can I now read the GPS data? I did a lot of research and found a of information, but as a guy who (yet) knows nothing about this topic, this information is way too advanced. I installed gpsd, but what is the next step? Can someone help me to find a starting point?

Did you see any NMEA data in /dev/ttyUSB1

@avk

You have to send this to the mobile tty: /dev/ttyUSB2

AT!CUSTOM=“GPSENABLE”,1
AT!CUSTOM=“GPSSEL”,0
AT!CUSTOM=“GPSLPM”,0
AT!GPSNMEACONFIG=1,1

// Optional commands
AT+WANT=0 // Disable power to the antenna (passive antenna) - Default
AT+WANT=1 // Enable power to the antenna (active antenna)

// Enable only GPS (default)
AT!GPSNMEASENTENCE=1F

// Enable all constellations (reboot the modem now and only do the above sequence now)
AT!GPSNMEASENTENCE=C9FDF

You can find the bitmask options in the manual if you want other combinations

Then, to actually start the sentences you also need to send this, but to the NMEA port (ttyUSB1)
$GPS_START

This last one is not documented in the EM7565 manual
I found it in docs from another modem

You should start GPSD now and point it to ttyUSB1

Hope this helps :slight_smile:

@koenvandeputte

Thanks, that helped a lot :slight_smile:

Before your commands I added

AT!ENTERCND="A710"

With that, all AT commands get an OK response.

But I still have the problem that sending $GPS_START to the NMEA port doesn’t seem to have any effect. When I check the GPS status via AT commands I get this response:

AT!GPSSTATUS?

Current time: 2020 06 15 0 15:36:30

2020 06 10 2 14:52:30 Last Fix Status    = FAIL,  FAILCODE = 9
2020 06 10 2 14:52:30 Fix Session Status = FAIL,  FAILCODE = 9

No TTFF available

OK
AT!GPSLOC?
Not Available

OK

The FAILCODE 9 means

User ended the session

But what exactly does this mean? With AT!GPSFIX I can at least set the Fix Session Status to active but I still get no position. So what am I missing here?