When I test this module alone, I can't get a valid GPS in the monitor and the latitude and longitude keep showing 0 (I set the initial value of latitude and longitude to zero in the code). Is this happening because I have a bad signal indoors and the range of movement of the location is too small?
Do you get a GPS lock ?
How are you reading and examining the GPS data ?
Please post a sketch showing what you are doing
GPSs can be bad at acquiring a fix indoors, they really need to be outdoors with a good view of the sky.
There is code you can run that will show the actual data the GPS is producing and from that you can tell how weak the received signals actually are.
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I use the GPRMC output.
The character after the time is the status.
'V' is no lock
'A' is lock. Position is good.
How long did you wait for synch. If you ordered from China, and you are in California, it could take many hours (I have waited overnight) for the GPS to find where you are.
First time fix from cold (or China) for a Neo6m will be about 45 seconds if the GPS is working properly and is outside with a good view of the sky.
Not my experience, I have a dozen or more and they all needed many hours. I am in Northern Ontario, Canada, maybe you are a few thousand miles closer?
You need to check the GPGSV sentences to see how many satellites are in view and how strong the signals are.
For sure I have had GPSs that take an age to get a fix, but in each and every case the GPS has been reporting very weak signals, i.e. was faulty.
Check the time to first fix spec for a Neo6M GPS in the datasheet;
That certainly looks impressive, I just don't understand how it is possible, but I don't understand lots' of things. Maybe I have a different dumber GPS module.
Very long cold fix time might have been an issue in the early 80s when GPS became available.
But electronics has moved on since then and GPS now have many channels they can listen to at the same time so can quickly pick up signals from the GPSs that happen to be in view.
Cold fix times are a good indication of the performance of a GPS, or in particular its antenna, see a heap of practical tests on cold fixing here;
https://stuartsprojects.github.io/2020/09/10/GPS-antennas-effectiveness-and-weight.html
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