Asset Tracker v2 SUPL Integration

[ibiglari]

Hi,

This might sound like a silly question, but is there a way to use SUPL library with Asset Tracker v2 with LwM2M integration without having to trade off logging? SUPL library is quite massive and linking against it requires AT client library and logging to be disabled. Even trying to enable LOG_MINIMAL seems not to be sufficient:

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[30/30] Linking C executable zephyr\zephyr.elf
Memory region         Used Size  Region Size  %age Used
           FLASH:       40410 B        48 KB     82.21%
             RAM:       28024 B     211736 B     13.24%
        IDT_LIST:          0 GB         2 KB      0.00%
[425/447] Linking C executable zephyr\zephyr_pre0.elf
FAILED: zephyr/zephyr_pre0.elf zephyr/zephyr_pre0.map 
cmd.exe /C "cd . && C:\ncs\toolchains\v2.2.0\opt\zephyr-sdk\arm-zephyr-eabi\bin\arm-zephyr-eabi-gcc.exe  -gdwarf-4 @CMakeFiles\zephyr_pre0.rsp -o zephyr\zephyr_pre0.elf  && cmd.exe /C "cd /D C:\ncs\v2.2.0\nrf\applications\asset_tracker_v2\build\zephyr && C:\ncs\toolchains\v2.2.0\opt\bin\cmake.exe -E echo ""
c:/ncs/toolchains/v2.2.0/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.1.0/../../../../arm-zephyr-eabi/bin/ld.exe: zephyr\zephyr_pre0.elf section `rodata' will not fit in region `FLASH'
c:/ncs/toolchains/v2.2.0/opt/zephyr-sdk/arm-zephyr-eabi/bin/../lib/gcc/arm-zephyr-eabi/12.1.0/../../../../arm-zephyr-eabi/bin/ld.exe: region `FLASH' overflowed by 35440 bytes
collect2.exe: error: ld returned 1 exit status
ninja: build stopped: subcommand failed.
FATAL ERROR: command exited with status 1: 'c:\ncs\toolchains\v2.2.0\opt\bin\cmake.EXE' --build 'c:\ncs\v2.2.0\nrf\applications\asset_tracker_v2\build'

Kind Regards,
Iman

[Øyvind]

Hello,

Do you have "debug options" enabled in the board configuration settings?

Will have a look at your issue but will not have an answer before Monday. 

Kind regards,
Øyvind

[Øyvind]

My apologies for the late reply. Will get back to you today. 

Kind regards,
Øyvind

[Øyvind]

Could you provide more information on how you have integrated the SUPL library to the Asset Tracker v2? 

[ibiglari]

Hi,

Sure.

I am using LwM2M, so, in overyal-lwm2m.conf:

CONFIG_SUPL_CLIENT_LIB=y

I have also copied (and slightly modified) assistance.h and assistance_supl.c from 9160 GNSS sample.

Changes to Asset Tracker v2 code:

In main.c:

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    self.thread_id = k_current_get();

#if defined(CONFIG_SUPL_CLIENT_LIB)

    assistance_init();

#endif

    err = module_start(&self);

    if (err) {

        LOG_ERR("Failed starting module, error: %d", err);

        SEND_ERROR(app, APP_EVT_ERROR, err);

    }

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In lwmem_codec.c:

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int cloud_codec_encode_agps_request(struct cloud_codec_data *output,

                    struct cloud_data_agps_request *agps_request)

{

#if defined(CONFIG_SUPL_CLIENT_LIB)

       /* SUPL doesn't usually provide satellite real time integrity information. If GNSS asks

        * only for satellite integrity, the request should be ignored.

        */

       if (agps_request->request.sv_mask_ephe == 0 &&

           agps_request->request.sv_mask_alm == 0 &&

           agps_request->request.data_flags == NRF_MODEM_GNSS_AGPS_INTEGRITY_REQUEST) {

               LOG_INF(" Ignoring assistance request for only satellite integrity\r\n");

       } else {

               LOG_INF(" Assistance data needed, ephe 0x%08x, alm 0x%08x, flags 0x%02x\r\n",

                       agps_request->request.sv_mask_ephe,

                       agps_request->request.sv_mask_alm,

                       agps_request->request.data_flags);

               assistance_request(&agps_request->request);

       }

       return -ENODATA;

#else

    ARG_UNUSED(output);

    int err;

    err = location_assistance_agps_set_mask(&agps_request->request);

    if (err) {

        LOG_ERR("location_assistance_agps_set_mask, error: %d", err);

        return err;

    }

    /* Disable filtered A-GPS. */

    location_assist_agps_set_elevation_mask(-1);

    err = lwm2m_engine_set_u32(LWM2M_PATH(LWM2M_OBJECT_CONNECTIVITY_MONITORING_ID, 0,

                          CELLID),

                   agps_request->cell);

    if (err) {

        return err;

    }

    err = lwm2m_engine_set_u16(LWM2M_PATH(LWM2M_OBJECT_CONNECTIVITY_MONITORING_ID, 0,

                          SMNC),

                   agps_request->mnc);

    if (err) {

        return err;

    }

    err = lwm2m_engine_set_u16(LWM2M_PATH(LWM2M_OBJECT_CONNECTIVITY_MONITORING_ID, 0,

                          SMCC),

                   agps_request->mcc);

    if (err) {

        return err;

    }

    err = lwm2m_engine_set_u16(LWM2M_PATH(LWM2M_OBJECT_CONNECTIVITY_MONITORING_ID, 0,

                          LAC),

                   agps_request->area);

    if (err) {

        return err;

    }

    agps_request->queued = false;

    return 0;

#endif

}

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In src/cloud/CMakeLists.txt:

target_sources_ifdef(CONFIG_SUPL_CLIENT_LIB app

                     PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/lwm2m_integration/assistance_supl.c)                    

The only change I made to assistance_supl.c was to hard-code SUPL_SERVER and SUPL_SERVER_PORT:

#define SUPL_SERVER        "supl.google.com"

#define SUPL_SERVER_PORT   7276

//BUILD_ASSERT(sizeof(CONFIG_GNSS_SAMPLE_SUPL_HOSTNAME) > 1, "Server hostname must be configured");

Hope this helps.

Kind Regards,
Iman

[Øyvind]

Iman, thank you for providing this information. Would if be possible to share your project instead?

Have you considered using nRF Cloud AGPS instead?

Do you have P-GPS enabled as well? This requires a good amount of flash.

Kind regards,
Øyvind

[ibiglari]

Hi,

Thanks for your reply.

I am not using P-GPS.

I thought about using nRF Cloud AGPS, but I'd rather use LwM2M location assistance mechanism if I could implement it in my LwM2M server (which is basically a Leshan server object). This would get rid of the massive SUPL library altogether.

Do you have any documentations (or better yet, a working sample) regarding how to respond to a LwM2M location assistant request?

Also, project folder here. asset_tracker_v2.7z

I have created a few logger macros to replace LOG_XXX so that I could have some sort of logging while using SUPL. You can perform a Find/Replace to revert back to normal logging.

Kind Regards,
Iman

[Øyvind]

Hi Iman, 

ibiglari said:

Do you have any documentations (or better yet, a working sample) regarding how to respond to a LwM2M location assistant request?

Yes, our nRF Cloud documentation shows how to communicate with the nRF Cloud Location services: https://docs.nrfcloud.com/LocationServices/LocationServicesOverview/

Have a look at the LwM2M location services which uses AVsystems.

Kind regards,

Øyvind

[ibiglari]

Hi,

Had a quick look. While it sounds promising, I'm afraid the costs are a setback. Specially since it seems that REST API does not have the same number of free calls per month as MQTT

I might end up implementing SUPL support on my server side instead of the client if SUPL library cannot be somehow shrunk. I opened another ticket for that, but not sure if that is going to be feasible.

In the meantime, were you able to reproduce the issue with the code I attached?

Kind Regards,
Iman

[Øyvind]

ibiglari said:

In the meantime, were you able to reproduce the issue with the code I attached?

No, I am not able to build it on my computer. Still working on it. 

ibiglari said:

Specially since it seems that REST API does not have the same number of free calls per month as MQTT

That sounds a little weird, could you please point to where you found that information? 

Could you provide information on what your needs are and I will discuss with the nRF Cloud team.

[ibiglari]

Hi,

Øyvind said:

That sounds a little weird, could you please point to where you found that information? 

Read that on "Location Services in a cloud-to-cloud setup" page. It says "You must have an nRF Cloud Pro or Enterprise plan."

What I want to achieve at the end of the day is for my hardware on the field to only need to communicate to one entity on the cloud, using one protocol only. That would mean no need for SUPL client library, but that is, at least for now, far from being realised as I am still trying to make heads or tails of Google's SUPL client.

The end-goal for me is to have a single LwM2M server that can reply to A-GPS or P-GPS requests by proxying it to either a SUPL service, or to an A-GPS cloud provider. This way the hardware in the field needs to only know about one server, one set of credentials, and one communication protocol (UDP in this case).

Kind Regards,
Iman