Transmit GPS data to website

RE: Transmit GPS data to website

Håkon Alseth — Wed, 13 Jan 2021 07:34:33 GMT

Hi,

Don't change the source files, you should set the log level on a project level:

https://docs.zephyrproject.org/latest/reference/kconfig/CONFIG_LOG_DEFAULT_LEVEL.html

You can access this by entering "menuconfig", either via SeggerEmbeddedStudio (nordic edition) or via command line (cd my-project/build-folder && ninja menuconfig)

Then you should also choose "LTE_LINK_CONTROL_LOG_LEVEL_DBG".

Kind regards,

Håkon

RE: Transmit GPS data to website

paul_tanner — Sun, 10 Jan 2021 11:46:10 GMT

So I made that error in modem_configure() non-fatal (a hack in ltc_lc.c) and it now does GPS and transmits the result via UDP. This is almost a solution apart from the fact that I hacked ltc_lc.c. I'd like a way to do this without that hack if possible to make it more upgrade-proof.

Also, if I want to restrict the log a bit i'd like to find out where CONFIG_LTE_LINK_CONTROL_LOG_LEVEL is defined.

Thx for any suggestions.

Regards

RE: Transmit GPS data to website

paul_tanner — Fri, 08 Jan 2021 16:23:07 GMT

Thx Håkon

OK. modem_configure() is trying to set the AT%XSYSTEMMODE - which is *already* correctly set.

(I have CONFIG_LTE_NETWORK_MODE_NBIOT_GPS=y in prj.conf)

BTW. To find this out I had to edit lte_lc.c whereas I would have preferred to turn on debugging. I tried adding:

#define NRF_AT_CMD_LOG_LEVEL NRF_LOG_LEVEL_DEBUG

in main.c but that had no effect.

What next?

Regards.

RE: Transmit GPS data to website

Håkon Alseth — Fri, 08 Jan 2021 13:30:29 GMT

Hi,

[quote user="paul_tanner"]This is happening inside lte_lc_init_and_connect_async() for which AFAIK we do not have the source.[/quote]

That function is inside lte_lc.c: https://github.com/nrfconnect/sdk-nrf/blob/master/lib/lte_link_control/lte_lc.c#L744

Do you know which AT command is failing? Does any of them work?

Kind regards,

Håkon

RE: Transmit GPS data to website

paul_tanner — Wed, 06 Jan 2021 17:49:51 GMT

Thx Håkon

I tried that. It gets to modem_configure() - same code as in UDP sample - and we then fail with:

```

Could not send AT command error -8

```

This is happening inside lte_lc_init_and_connect_async() for which AFAIK we do not have the source.

Regards.

RE: Transmit GPS data to website

Håkon Alseth — Wed, 06 Jan 2021 11:10:11 GMT

Hi Paul,

My strongest apologies! This comment from me is written a bit too fast (ie: its wrong..)

[quote user="hkn"]Please check that "modem_configure()" isn't called[/quote]

You should check that modem_configure hasn't been called yet, before setting system permissions, like XSYSTEMMODE.

So, issue your AT-commands, then call modem_configure() to connect to the LTE network.

Kind regards,

Håkon

RE: Transmit GPS data to website

paul_tanner — Wed, 06 Jan 2021 08:41:32 GMT

Thx Håkon

modem_configure() *was* being called; CONFIG_LTE_AUTO_INIT_AND_CONNECT=n is set.

So I removed modem_configure(). The result was that we never get the LTE_LC_EVT_RRC_UPDATE (idle) event so it just hangs.

Is something else needed instead of modem_configure()? (per the udp example)

Presumably the lack of modem_configure would also prevent sending of data via udp?

Regards.

RE: Transmit GPS data to website

Håkon Alseth — Tue, 05 Jan 2021 08:43:36 GMT

Hi,

[quote user="paul_tanner"]XSYSTEMMODE is probably redundant but why would it throw an error?[/quote]

Its highly likely because the modem is already enabled (AT+CFUN=1) at this point. Please check that "modem_configure()" isn't called, and that "CONFIG_LTE_AUTO_INIT_AND_CONNECT=n" is set in your project.

Kind regards,

Håkon

RE: Transmit GPS data to website

paul_tanner — Tue, 05 Jan 2021 08:41:18 GMT

Thx Håkon

Yes. The first thing I did was to test both GPS and UDP examples.

Only then did I try to put them together to make a minimal tracker using UDP and without the need for all the other good stuff in your asset_tracker app.

So I now wait for udp Idle.

However, from the code in the gps sample I then get an error from

```

at_cmd_write(at_commands[i])

```

AT_XSYSTEMMODE, (fails on this one)
AT_MAGPIO,
AT_COEX0,
AT_ACTIVATE_GPS

so GPS is not activated.

XSYSTEMMODE is probably redundant but why would it throw an error?

Regards.

RE: Transmit GPS data to website

Håkon Alseth — Tue, 05 Jan 2021 07:06:28 GMT

You can evaluate the gps without using LTE, by running the "gps" example.

This doesn't require LTE, but does require that you're outside (or the GPS-antenna shall be outside) while testing.

Kind regards,

Håkon

RE: Transmit GPS data to website

paul_tanner — Mon, 04 Jan 2021 16:34:50 GMT

Many thx Håkon

I guess this means that if testing without a connection it will wait indefinitely - if you let it.

That should not be a problem as you can't send anything until you get a signal.

I'll try this when I'm in range of a cell tower.

Regards, Paul

RE: Transmit GPS data to website

Håkon Alseth — Mon, 04 Jan 2021 11:16:39 GMT

Hi,

[quote user="paul_tanner"]I tried setting CSCON=0 when initialising the GPS.[/quote]

This is an event coming from the modem, which indicates if the LTE link is active or not. You should set the CSCON non-zero to enable notification, and then you should get it through your AT notification handler (if set).

By setting it to 0, you're disabling the notification.

[quote user="paul_tanner"]If I then try to initialise a UDP connection lte_lc_init_and_connect_async(lte_handler) fails.[/quote]

Is "CONFIG_LTE_AUTO_INIT_AND_CONNECT" disabled? If this is enabled, the link is enabled and established prior to entering main.

[quote user="paul_tanner"]I'm not clear on the sequence I need to initialise both GPS and UDP.[/quote]

You first need to enable the usage of GPS, for instance by enabling CONFIG_LTE_NETWORK_MODE_LTE_M_GPS=y (or if NB1: CONFIG_LTE_NETWORK_MODE_NBIOT_GPS)

This will set the permission in AT%XSYSTEMMODE.

If you are able to successfully enter PSM or eDRX, and you have ensured the CSCON event is enabled (See the docs here: https://infocenter.nordicsemi.com/topic/ref_at_commands/REF/at_commands/packet_domain/cscon_set.html?cp=2_1_6_16_0), you can start the GPS, as shown in the "gps" sample.

The CSCON event is available through the lte_lc library, and samples like the udp/cloud_client/asset_tracker, implement a print when you're connected or idle:

https://github.com/nrfconnect/sdk-nrf/blob/master/samples/nrf9160/udp/src/main.c#L79-L82

when CSCON (or lte_lc::LTE_LC_EVT_RRC_UPDATE) gives you a notification "idle", you can start the GPS.

Kind regards,

Håkon

RE: Transmit GPS data to website

paul_tanner — Wed, 23 Dec 2020 10:59:51 GMT

Thx Håkon,

I tried setting CSCON=0 when initialising the GPS.

(After looking at the code in asset_tracker I also saw it use lte_lc_psm_req(true))

If I then try to initialise a UDP connection lte_lc_init_and_connect_async(lte_handler) fails.

(Initialisation code from the UDP example)

I'm not clear on the sequence I need to initialise both GPS and UDP.

further...

I wanted to see why lte_lc_init_and_connect_async is failing but this seems to be part of the distribution that is shipped in binary.

Specifically, the error is:

modem_configure()
I: Using legacy LTE PCO mode...
I: PDP Context: AT+CGDCONT=0,"IP","lpwa.vodafone.iot"
E: Could not send AT command, error: -8

Which is odd because when initialising the GPS we already sent 4 AT commands without error.

This part of UDP initialisation works fine if I comment out the GPS initialisation

Thx.

RE: Transmit GPS data to website

Håkon Alseth — Mon, 21 Dec 2020 10:04:26 GMT

Hi,

The asset_tracker shows how to connect to a cloud based system, and send certain sensors + gps data to the cloud.

If you want a simpler solution, like a tcp/udp connection directly to your own server, I would recommend that you look at the "gps" sample, and add your own implementation around this.

Note that there's a restriction towards getting GPS and LTE concurrent, which is that you have to be in eDRX or PSM mode in order to use the GPS. A recommended use-case is to use the AT CSCON event to signal when you can or cannot use the GPS.

Kind regards,

Håkon