GPS Interface

GPS

The MConn display includes an onboard GNSS (GPS) module that outputs standard NMEA data over a serial interface. You can monitor this data directly using a terminal application on the device.

Checking if GPS is available

Before testing GPS data, it is helpful to confirm that the GPS serial interface exists and is initialized by the system.

1. Check for the GPS Device

Run the following command:

ls /dev/ttymxc*

You should see the entry /dev/ttymxc1 as a response.

2. Verify the GPS Device is accessible

Check permissions and confirm the device is recognized by running the following command:

ls -l /dev/ttymxc1

You should see an output similar to:

crw-rw---- 1 root dialout ... /dev/ttymxc1

Testing GPS Output

Follow these steps to verify that the GPS module is working correctly.

1. Open a serial terminal to the GPS interface:

screen /dev/ttymxc1

This connects to the GPS serial interface and displays incoming data.

2. Monitor the output for NMEA messages:

After opening the terminal, you should start seeing output similar to:

$GNGLL,...
$GPGGA,...
$GNRMC,...

3. Verify GPS Data:

Please check the following:

The output is continuously updating (new lines every second)
Latitude (N) and Longitude (W) values are present
Coordinates are reasonably close to your actual location

4. Exit the screen terminal:

To exit the screen session, press: Ctrl+A, then K, then y