GNSS on 5G Module

This page will introduce the usage of the GPS/GNSS capabilities on 5G module (RM500Q-GL). This includes how to enable the GNSS functions and get the raw satellite data from the module, And how to display the Positional data graphically.

echo -e "AT+QGPS=1\r\n" > /dev/ttyUSB2

Obtain GPS data through /dev/mhi_LOOPBACK port.

$ cat /dev/mhi_LOOPBACK

$GPVTG,,T,,M,,N,,K,N*2C
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGGA,,,,,,0,,,,,,,,*66
$GPRMC,,V,,,,,,,,,,N*53
$GPVTG,,T,,M,,N,,K,N*2C

Before you begin, install gpsd and the client programs by running the following command.

$ sudo apt install gpsd gpsd-clients

Open the gpsd configuration file.

$ sudo vim /etc/default/gpsd

Make the necessary changes to specify the correct device node.

 Devices gpsd should collect to at boot time.
# They need to be read/writeable, either by user gpsd or the group dialout.
+ DEVICES="/dev/mhi_LOOPBACK"
 
# Other options you want to pass to gpsd
+ GPSD_OPTIONS=""
 
# Automatically hot add/remove USB GPS devices via gpsdctl
+ USBAUTO="true"

Restart the services.

$ sudo systemctl restart gpsd

Start the cgps client to observe data.

$ cgps

Start the gpsmon client to observe data.

$ gpsmon