GPS FIX while moving

[RicardoPereira]

Hi, 

I have been implementing the GPS on my thingy:91 with the firmware v1.2.0

I'm able to do a cold start and get a FIX is if in do not move the board for around 100 seconds. And then i can trace my path.

However, if i do not stop to do the cold start, the gps will never get fix. 

Why is this happening and which settings should be change to make it work ? Frequency ? 

[Didrik Rokhaug]

Hi.

Could you tell me a bit more about your setup?

How much are you moving the Thiny while it is searching?

What version of the Thingy do you have?

How fast are you moving?

Does the Thingy have a clear view of the sky, or is something covering it? If so, what?

What application were you using? Were you using LTE concurrently?

Best regards,

Didrik

[RicardoPereira]

Hi Didrik Rokhaug

It is a simple application. It is connected with LTE-M enabling PSM. When I get a FIX I sent it to my server. (It works but i have to stop to get the first fix and then i can trace my path) 

Slowly, moving it while walking. the environment is the one that you see on the map. I'm just holding it

The version is 1.0.2

Regards, 

[RicardoPereira]

Hi Didrik Rokhaug 

No idea on how to improve/fix that ? 

[Martin Lesund]

Hi Ricardo,
It should be possible to get a fix at pedestrian speeds.
I would recommend you to flash mfw 1.2.0 and use NCS v1.3.0 with a-gps enabled which should improve the cold start fix much quicker.

Do you have a nrf91DK with an external antenna to compare the performance with?

BR,
Martin L.

[RicardoPereira]

Hi Martin Lesund

No I do not have the DK yet but I will get one soon. 

Yes I am thinking to implement A-GPS to solve this problem. For that I used the GPS sample with SUPL.

It works well to fix the GPS (40-60s). However, when i want to sent the data through HTTP I get the error 12 with getaddrinfo after sending 2-3 messages. (I active LTE before sending the data) I already try to increase the size of the buffer CONFIG_NRF_CLOUD_MQTT_MESSAGE_BUFFER_LEN but still get the message. 

I also try to enable PSM. However, the performance with the GPS using PSM are really bad (Over 3 minutes to get a fix without moving)...  

Any idea of what is going on ?