How to disable +CEREG notifications

RE: How to disable +CEREG notifications

Tim_AFD — Thu, 30 Jan 2020 15:57:20 GMT

Thanks Heidi -- that did it!

We wrapped the "write_uart_string():" function with #ifdefs to enable it only if logging or printk are enabled and it supresses the +CEREG notifications properly now.

Tim

RE: How to disable +CEREG notifications

Heidi — Thu, 30 Jan 2020 13:50:36 GMT

Hi again, Tim.

After some digging, we found it. It is coming from the at_host library. In at_host.c, in response_handler there is the line

write_uart_string(response);

which is writing these +CEREG updates.

But in the asset_tracker sample, to disable the AT Host library, you need to use the USE_AT_HOST config, which is found in the Kconfig file.

Best regards,

Heidi

RE: How to disable +CEREG notifications

Tim_AFD — Wed, 29 Jan 2020 23:31:16 GMT

In further testing today, I observed two additional +CEREG notifications after the two that occur at startup. It appears they were triggered by the Cell ID changing. I'm testing in a static setting, on a bench. If this is triggered by every tower change, it could really cause an issue if UART_0 is disabled. Here's the log with the timestamp data:

2020-01-29T22:52:12.161Z DEBUG modem << ***** Booting Zephyr OS build v2.0.99-ncs1 *****\x0D\x0A
2020-01-29T22:52:12.168Z DEBUG modem << [00:00:00.005,035] \x1B[0m<inf> mcuboot: Starting bootloader\x1B[0m\x0D\x0A
2020-01-29T22:52:12.176Z DEBUG modem << [00:00:00.013,427] \x1B[0m<inf> mcuboot: Primary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x1\x1B[0m\x0D\x0A
2020-01-29T22:52:12.186Z DEBUG modem << [00:00:00.026,580] \x1B[0m<inf> mcuboot: Scratch: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3\x1B[0m\x0D\x0A
2020-01-29T22:52:12.192Z DEBUG modem << [00:00:00.039,062] \x1B[0m<inf> mcuboot: Boot source: primary slot\x1B[0m\x0D\x0A
2020-01-29T22:52:12.199Z DEBUG modem << [00:00:00.050,384] \x1B[0m<inf> mcuboot: Swap type: none\x1B[0m\x0D
2020-01-29T22:52:12.543Z DEBUG modem << [00:00:00.500,915] \x1B[0m<inf> mcuboot: Bootloader chainload address offset: 0xc000\x1B[0m\x0D\x0A
2020-01-29T22:52:12.549Z DEBUG modem << [00:00:00.510,955] \x1B[0m<inf> mcuboot: Jumping to the first image slot\x1B[0m\x0D
2020-01-29T22:52:14.662Z DEBUG modem << +CEREG: 2,"C00C","02F00103",7,0,0,"11100000","11100000"\x0D\x0A
2020-01-29T22:52:15.733Z DEBUG modem << +CEREG: 1,"C00C","02F00103",7,,,"11100000","00100110"\x0D\x0A
2020-01-29T22:53:32.758Z DEBUG modem << +CEREG: 1,"C00C","02EE9002",7,,,"11100000","00100110"\x0D\x0A
2020-01-29T22:54:43.141Z DEBUG modem << +CEREG: 1,"C00C","02F00103",7,,,"11100000","00100110"\x0D

And, here's the current state of my logging/serial related prj.conf settings:

CONFIG_SERIAL=y
CONFIG_UART_NRFX=y
CONFIG_UART_INTERRUPT_DRIVEN=y
CONFIG_UART_2_NRF_UARTE=y

# Console
CONFIG_STDOUT_CONSOLE=n
CONFIG_BOOT_BANNER=n
CONFIG_PRINTK=n
#CONFIG_CONSOLE_SUBSYS=y
#CONFIG_CONSOLE_HANDLER=y
#CONFIG_CONSOLE_GETCHAR=y

# LOG config:
CONFIG_LOG=n
CONFIG_LOG_IMMEDIATE=n
CONFIG_AWS_FOTA_LOG_LEVEL_DBG=n		
CONFIG_AWS_JOBS_LOG_LEVEL_DBG=n		
CONFIG_LTE_LINK_CONTROL_LOG_LEVEL_DBG=n		
CONFIG_AT_NOTIF_LOG_LEVEL_DBG=n		
CONFIG_NRF_CLOUD_LOG_LEVEL_DBG=n	
CONFIG_NRF9160_GPS_LOG_LEVEL_DBG=n	
CONFIG_MODEM_INFO=n
CONFIG_NET_LOG=n
CONFIG_MQTT_LOG_LEVEL_DBG=n
CONFIG_AT_HOST_LIBRARY=n

Thanks,

Tim

RE: How to disable +CEREG notifications

Tim_AFD — Wed, 29 Jan 2020 20:27:16 GMT

Something compressed the screenshot in my above reply. Here's a repost that will hopefully be more legible.

Thanks,

Tim

RE: How to disable +CEREG notifications

Tim_AFD — Wed, 29 Jan 2020 20:25:44 GMT

Hello Heidi,

I added "CONFIG_AT_HOST_LIBRARY=n" to prj.config, reloaded/rebuilt the project, and still get the +CEREG notifications at start up:

This seems to confirm that they're not coming from the AT_HOST library, in addition to the printk or console/log routes. Is there something in the modem firmware that is sending these?

Thanks,

Tim

RE: How to disable +CEREG notifications

Heidi — Tue, 28 Jan 2020 09:06:13 GMT

I understand. Try disabling the whole at_host library with AT_HOST_LIBRARY = n.

RE: How to disable +CEREG notifications

Tim_AFD — Mon, 27 Jan 2020 17:50:51 GMT

Hello Heidi,

Yes, I tried setting AT+CEREG=0, but that does break the link layer.

Setting 'Config_Serial=n' globally disables all UARTs. This is not acceptable, our application requires a UART interface to an external device. We control both ends of this UART_2 link and I can gurantee that the external device will not send data to the nRF9160 when UART_2 is disabled.

Power consumption with UART_0 enabled is very high.

Thanks,

Tim

RE: How to disable +CEREG notifications

Heidi — Mon, 27 Jan 2020 10:09:49 GMT

You could always set AT+CEREG=0 to disable these messages, but I imagine you might get a host of other problems, as the lte_link_control layer uses the notifications to check the connection status. If you just want to disable the debugging messages, you could disable the serial output like this:

CONFIG_SERIAL=n

Turning of UART_0 is not the right way to do it, as it will most likely crash other parts of your application.

RE: How to disable +CEREG notifications

Tim_AFD — Fri, 24 Jan 2020 15:20:29 GMT

Hello Heidi,

My loging/printk settings seem to supress notifications except for those first two +CEREG ones. But shouldn't those first two be supressed also? Since they are still present every time the application starts, there appears to be an active mechanism for console notifications.

Is it safe to turn off UART_0, or is there a risk of another notification that will crash my application?

Thanks,

Tim

RE: How to disable +CEREG notifications

Heidi — Fri, 24 Jan 2020 14:42:33 GMT

Hi, are you saying you fixed the problem?

I have asked the NCS team what the easiest way to suppress the +CEREG requests is.

Best regards,

Heidi

RE: How to disable +CEREG notifications

Tim_AFD — Wed, 22 Jan 2020 20:19:08 GMT

Here's the Link Monitor output showing two +CEREG notifications at start up:

My log config changes do seem to supress the follow on notifications now. I've not had it crash thus far today even though I'm still getting the two notifications at start up.

Thanks,

Tim