EC-25 odd GPS behaviour

Raspberry Pi Network HATs 3G/4G&LTE Base HAT
1

I have an odd issue with the GPS. I am using with RPi4 and everything works great in the lab.
However, when I move the setup from the lab, everything keeps working except the GPS data. I can use the setup on my car and have tried using static some miles from the lab but the lat/lon still shows the lab location.

Even the $GPRMC sentence stays the same

Any ideas would be gratefully received.

Thanks
Ian

2

Hi @ian.thomas,

Could you provide some of the:

[$GPGSA] - GPS DOP and active satellites
[$GPGSV] - GPS Satellites in view
[$GPGGA] - Global Positioning System Fix Data

sentences while you are at your lab and while away?

And for yourself, check:

[$GPGLL] - Geographic position, latitude / longitude

as this is where I always get my ‘you are here’ info.

S

3

Thanks Shawn.

I am testing again tomorrow and will capture the data to share (both Lab and Mobile)

Ian

4

Hi,

Thanks for the suggestion Shawn.

Having completed tests and captured data the issue appears to be that, when I lose connection, I still continue to read the NMEA sentences and these appear to be cached.

Once connection is re-established the application starts processing the cached list.

Now I just need to identify where the data is cached so I can add management of the data.

Ian

1 Like
5

resolved.

just needed to add [port].reset_input_buffer()

Ian