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FONA 3G GPS latitude declination
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FONA 3G GPS latitude declination

by pandread on Mon Apr 08, 2019 2:36 pm

So, I can communicate to FONA 3G with an Arduino Nano and I am now exploring the
Fonatest sketch. The problem is that I am getting a constant latitude declination of 0.30 points.
i.e. True = 23.43
Wrong = 23.73

FONA insists on the second option, but I have not even been there before.

I do not think any magnetic or electric material interferes with the antenna in any way.

Any ideas?

Thank you.

pandread
 
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Joined: Fri Apr 05, 2019 4:55 pm

Re: FONA 3G GPS latitude declination

by adafruit_support_mike on Tue Apr 09, 2019 1:51 am

Double-check the encoding.

Some GPS devices list coordinates in degrees, minutes, seconds, and fractional seconds. Others use degees, minutes, and fractional minutes. The version that uses seconds rolls over from 005900 to 010000, while the fractional-minutes version goes to 006000.

A lot of unexplained offsets happen that way.

adafruit_support_mike
 
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Re: FONA 3G GPS latitude declination

by pandread on Sat Apr 13, 2019 1:40 pm

Thank you support.

How do I check encoding?
How do I change encoding or convert if possible?

I was using the FONA 3G Coords in here https://www.mapcoordinates.net/en to verify.

So does that mean that another GPS MAP web/app might be more fit for FONA coords?

pandread
 
Posts: 6
Joined: Fri Apr 05, 2019 4:55 pm

Re: FONA 3G GPS latitude declination

by adafruit_support_mike on Sun Apr 14, 2019 12:47 am

There are online coordinate converters you can use:

https://www.gps-coordinates.net/gps-coo ... -converter

You can also check various mapping services to see which standard they use. There's no way to change the format a FONA uses though.

adafruit_support_mike
 
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Joined: Thu Feb 11, 2010 2:51 pm

Please be positive and constructive with your questions and comments.