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GPS not working on Fona 3G
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GPS not working on Fona 3G

by oscmejia on Thu Jan 14, 2021 8:53 am

Hi Guys,

I’m testing a Fone 3G I got a few weeks ago but I can’t get the GPS to work.

I’m using an Arduino Nano and follow the instructions on your site.
Screen Shot 2021-01-11 at 10.12.20 AM.png
Screen Shot 2021-01-11 at 10.12.20 AM.png (776.96 KiB) Viewed 392 times



These I what Is see when I try the test code:

Screen Shot 2021-01-11 at 10.04.39 AM.png
Screen Shot 2021-01-11 at 10.04.39 AM.png (66.93 KiB) Viewed 391 times


Screen Shot 2021-01-11 at 10.06.57 AM.png
Screen Shot 2021-01-11 at 10.06.57 AM.png (91.64 KiB) Viewed 391 times


Any ideas?

Thanks in advance

oscmejia
 
Posts: 3
Joined: Fri Jul 10, 2020 5:36 pm

Re: GPS not working on Fona 3G

by rskup on Thu Jan 14, 2021 11:16 pm

Looking at the wiring photo, I zoomed in best I could, did you run 5V to the Vio pin on the Fona? Isn't the Nano 3V logic?

Also, is that an active or passive antenna for the GPS?

And just a bit confused, looks like you're powering both boards via the USB, but then tied their 5V pinouts together?

rskup
 
Posts: 84
Joined: Sat Aug 01, 2020 9:04 pm

Re: GPS not working on Fona 3G

by oscmejia on Sat Jan 16, 2021 4:28 pm

Thank for your response @rskup.

Probably I'm doing something wrong, but here is my reasoning and what I see:

Yes, the arduino is 3v, and here (https://learn.adafruit.com/adafruit-fon ... ut/pinouts) I see this:
These pins are all 3-5V input safe and if they are an output, the logic level is whatever Vio is set to.


I tried both, active and pasive antenas:

Screen Shot 2021-01-16 at 3.23.38 PM.png
Screen Shot 2021-01-16 at 3.23.38 PM.png (926.1 KiB) Viewed 364 times



And yes, I'm powering with both, USB, and from the Arduino board. If I remove any of those, the Fona just doesn't boot. I was expecting that it should wrk with the 5v from the board, but it doesn't.


any suggestions?

oscmejia
 
Posts: 3
Joined: Fri Jul 10, 2020 5:36 pm

Re: GPS not working on Fona 3G

by rskup on Sun Jan 17, 2021 1:11 pm

Some thoughts -- as I understand it, Vio needs to be at the same voltage as the logic voltage. From the tutorial, the section on pinouts: "A 5V micro (like Arduino) should have it be 5V, a 3V logic micro should set it to 3V".

I use an Adafruit Feather (#2771), which is also 3V logic, to control my FONA 3G. I tie the 3V output on the Feather to the Vio pinout on the FONA.

Something else that might help -- if you have decided to only use an active antenna, you also need to solder that "bias" bridge near the connector, described in the tutorial under "Antenna Ports".

Of course, if you decide to only use a passive antenna, you don't solder that bridge. But from various articles I've read if you do use a passive antenna, there will be a several minute delay before the GPS will begin working the first time it's powered up. Has something to do with "data tables" being downloaded, see link below:

https://stackoverflow.com/questions/342 ... gps-module

This may/may not matter -- the only other thought I have is since you are powering both boards with the USB is to remove the wires connecting their 5V pinouts together. Again, may not matter, but it doesn't seem needed and keeps things simpler.

Let me know what happens, I like tinkering with my FONA 3G, and also have a SIM7000G breakout board, I find this stuff interesting.

rskup
 
Posts: 84
Joined: Sat Aug 01, 2020 9:04 pm

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