Use supl_client_abort() A GPS SUPL nrf9160

[haohv6]

Hi.

I use GPS with SUPL client library, so I need your help.

I enabled CONFIG_AGPS_SRC_SUPL and use gps_agps_request() function to request agps

I found that in supl_start(), you don't use supl_client_abort() function.

This document (https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/libraries/others/supl_os_client.html#supl-client) noted that  "The SUPL client OS integration library then starts the SUPL session by calling the supl_client_session() function from the SUPL client library with the supl_session_ctx_t parameter. The application does not return from this function until the SUPL session is finished or the supl_client_abort() function is called.". 

I want use supl_client_abort() but segger embedded studio can't build it. It said "undefine reference supl_client_abort" although I included "supl_session.h".

How can I use it?

Thank you.

[haohv6]

This documet (https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/ug_nrf91_features.html#introduction) wrote that: 

To improve this, Nordic Semiconductor has implemented the following methods for acquiring a fix in a shorter time:

• A-GPS or P-GPS or a combination of both

• Low accuracy mode

I use your gps sample but i don't find where to set low accuracy mode ( GNSS might use only three satellites to determine a fix). 

How can I use it?

Thank you

[Håkon Alseth]

Hi,

 

haohv6 said:

I use your gps sample but i don't find where to set low accuracy mode ( GNSS might use only three satellites to determine a fix). 

How can I use it?

This is set in the gps configuration:

https://github.com/nrfconnect/sdk-nrf/blob/main/samples/nrf9160/agps/src/main.c#L110-L116

By adding the .accuracy = GPS_ACCURACY_LOW

 

haohv6 said:

In addition, my device uses the ATCFUN = 4 command to set the modem into sleep mode when inactive (for infrastructure reasons, my device cannot use PSM mode).

I noticed at + CFUN = 4 fast or slow respond depending on network conditions (sometimes a few seconds to minutes).

Is AT thread will wait until the socket reponds?

What is its timeout?

Minutes sounds quite long here. But it can take a couple of seconds for the link to gracefully shut down.

What are you doing prior to this sequence taking minutes to finish?

haohv6 said:

are there any cases supl_client_session() functions wait forever and do not return results( how long timeout is it).?

The session by default sets up a 1 second timeout:

https://github.com/nrfconnect/sdk-nrf/blob/v1.7.0/lib/agps/agps.c#L140-L150

 

Kind regards,

Håkon

[haohv6]

Hi.

I found that my connection thread hanged.
In that thread, I turned on AT + CFUN = 1 to connect to LTE  and send message, after sent message, It disconnects and go to sleep mode with AT + CFUN = 4.

So, I think it have a problem at AT thread in at_cmd.c

[Håkon Alseth]

Hi,

 

How often do you do this, ie CFUN=1/CFUN=4?

You are limited to 30 network attaches per hour as per GSMA guidelines (see here for documentation references). If this happens, the modem will wait until an hour has passed before you're able to attach to the network again.

 

Kind regards,

Håkon

[haohv6]

Hi

I use it 5 minutes once.

I known that it can't connect LTE more 30 times per hour, are there any cases AT thread hanged?

[Håkon Alseth]

Hi,

 

Do you wait until the network is available? Do you have a log showing the issue?

 

Kind regards,

Håkon

[haohv6]

Sorry, i don't have log about that. I will try catch it.

Another issue, I use Agps with supl, it work fine but sometimes, Its position is wrong ( It may be up to thousands of kilometers).

I use sdk 1.4.0 and fw 1.2.3, I don't use Low accurancy GPS mode.

What should i do? 

Thank you

[Håkon Alseth]

Hi,

 

haohv6 said:

Another issue, I use Agps with supl, it work fine but sometimes, Its position is wrong ( It may be up to thousands of kilometers).

That almost sounds like a corrupted buffer/uart output?

Does it continuously report the wrong position?

haohv6 said:

I use sdk 1.4.0 and fw 1.2.3, I don't use Low accurancy GPS mode.

Have you tested on a newer ncs version? We're currently on v1.7.1.

 

Kind regards,

Håkon