Improve GPS performance

[inyourface]

Hi 

I am working on the GPS for Thingy91. The Thingy91 is able to get the fix when I am outside and test it. However, when I am in the building by the window or on the balcony, Thingy91 never gets the first fix. 

1. Is there a way that can improve the GPS performance, like to get the first fix quicker and to get the fix in the building near the window?

2. Will A-GPS help this or is it the limitation of the antenna on the Thingy91 ?

Face.

[Martin Lesund]

Hi Face, 
Which version of the Thingy:91 do you use?

There is unfortunately an errata on the v1.0.0 version regarding the GPS performance using the on-board antenna.

So when testing GPS with the on-board antenna it is very important to have the device outside in open-sky so it can receive the GPS signals from the satellites.
Behind a window can be enough to degrade the signal.

I would recommend connecting a external GPS antenna for better performance, as mentioned in the errata.

A-GPS could help a bit since then the device do not need to download the ephemeris and almanac data from the satellites, but instead get that data from LTE network.
(This will cut down the time for the TTFF)

However the device would still need to be placed in a way that it can receive the satellites position to get a GPS fix.

Best regards,

Martin L.

[inyourface]

Martin,

My Thingy91 is version 1.0.2 (2020. 13). Does it still have the antenna issue? On the Thingy91, there is J2(u.fl) for connecting to an external GPS antenna. How to connect to it?

Does the latest version of Thingy91 have the fix and what is the version of it ?

Face

[Martin Lesund]

Hi Face,
Unfortunately, the improvement was introduced in the v1.4.0 version of the Thingy:91.

The J2 is a SWF type connector (Murata part no. MM8130-2600), so if you are using an external GPS antenna with the correct adapter (e.g. Murata part no. MXHS83QE3000)

see figure:  (also described in the documentation)

I would also recommend to try the A-GPS sample and also make sure that the device is in open sky outside with no obstacles such as windows etc. in the way.

Best regards,
Martin L.

[inyourface]

Hi Martin,

Can you please let me know where to purchase the latest version of Thingy91 or is it the same part number (NRF6943)? Does Digikey or Mouser have it ? Thanks.

[Martin Lesund]

https://www.nordicsemi.com/About-us/BuyOnline?search_token=nRF6943&series_token=nRF9160

Please check on the distributers sites.
If they do not have it in stock yet, they should soon have it

[inyourface]

Martin,

How can I know if they have the version v1.4.0 or does it have a separate part number? We would want to use the GPS on the Thingy91 with better antenna performance. Thanks.