nRF9160 - SYSTEM OFF Mode Current

RE: nRF9160 - SYSTEM OFF Mode Current

Kevin Kotinkar — Wed, 05 Jun 2024 11:12:14 GMT

Thanks Charlie, good input.

I will be able to test this next week. If confirmed, we should update our recommended answer/solution to this thread 🙂

Best,
Kevin

RE: nRF9160 - SYSTEM OFF Mode Current

Charlie — Tue, 04 Jun 2024 08:12:58 GMT

Hi Kevin,

Thanks for sharing your experience.

The specification claim the MCUOFF0 could reach a typical value 1.4uA.

I added nrf_modem_lib_shutdown(); after modem power off to shut it down, then got around 1.25uA on my nRF9160DK v1.1.0.

int main(void)
{
    printk("Hello World! %s\n", CONFIG_BOARD);
    nrf_modem_lib_init();
    printk("Turn off Modem and switch to SYSTEM OFF\n");
    lte_lc_power_off();
    nrf_modem_lib_shutdown();
    k_sleep(K_MSEC(1000));
    NRF_REGULATORS->SYSTEMOFF = 1;
    return 0;
}

You can test if it can help to decrease the current on your device further.

Best regards,

Charlie

RE: nRF9160 - SYSTEM OFF Mode Current

Kevin Kotinkar — Fri, 31 May 2024 12:03:53 GMT

Hi Charlie,

after back and forth testing, and updating my Toolchain + SDK again, I found out the following:

On previous SDK releases, nrf_modem_lib_init() is not required (tested this on NCS v1.8.0)
On current SDK releases (tested NCS v2.5.0,v2.6.0,v2.6.1) - nrf_modem_lib_init() is a MUST / requirement
- Your code provided code in the project *.zip file and the compiled ncs261_systemoff.hex seem to not include this line and thus don't work (for me).
- You should see a higher current when you fully power down the board and SiP and repower after a few seconds.
- It will seem to work, when you had a correct code sample flashed initially, and then reflash your code while measuring the current consumption and not going through a full power down cycle.
With a working code, I am at around 2uA, testing this with SICA B1, nRF9160 DK v1.0.1
I am slightly higher with the old SiP revision but it also works: 2.35 uA on SICA B0, nRF9160 DK v0.14.0
CONFIG_LTE_AUTO_INIT_AND_CONNECT was deprecated and removed with NCS v2.6.0 - but the cmake will report this, so its easy to catch if missing it.

My code looks as follows now. I don't know why I couldn't get the right result previously as I had the modem lib init() call already in my code. A clean SDK & Toolchain installation, plus a pristine build now helped me to find consistent results.

#include <zephyr/kernel.h>
#include <modem/lte_lc.h>
#include <modem/nrf_modem_lib.h>

int main(void)
{
	printk("Hello World! %s\n", CONFIG_BOARD);
	nrf_modem_lib_init();
	printk("Turn off Modem and switch to SYSTEM OFF\n");
	lte_lc_power_off();
	k_sleep(K_MSEC(1000));
    NRF_REGULATORS->SYSTEMOFF = 1;
	return 0;
}

prj.conf:

# Modem library and link control
CONFIG_LTE_LINK_CONTROL=y
CONFIG_NRF_MODEM_LIB=y

Attaching also my compiled hex file:
devzone.nordicsemi.com/.../ncs_5F00_261_5F00_sysoff_5F00_modemlib_5F00_init.hex

If someone is interested in NCS v1.8.0 compiled file (code is similar but no modem_lib_init() and the zephyr related includes are different):
devzone.nordicsemi.com/.../ncs_5F00_180_5F00_systemoff.hex

Best,
Kevin

RE: nRF9160 - SYSTEM OFF Mode Current

Charlie — Thu, 23 May 2024 08:10:12 GMT

Hi Kevin,

I did a try with your codes based on NCS v2.6.1 and nRF9160DK v1.1.0. I think it works as expected.

Could you try the attached codes? Maybe test with one more nRF9160DK in case it is related to HW?

devzone.nordicsemi.com/.../ncs261_5F00_systemoff.zip

devzone.nordicsemi.com/.../ncs261_5F00_SystemOff.hex

Best regards,

Charlie

RE: nRF9160 - SYSTEM OFF Mode Current

Kevin Kotinkar — Wed, 22 May 2024 15:51:18 GMT

Hi Charlie,

yes please have a try. I digged already further into this, and can reproduce the behavior.

My code works perfectly fine under NCS v1.8 for example.
Under NCS v2.5.0/v2.6.0 it does not work.

When I flash my compiled hex from NCS v1.8, and then flash my build hex based on NCS v2.5/2.6 it works until I completely power down the board and reset it. This is reproduceable.

SW Settings:
Under NCS v2.6.0 LTE AUTO INIT and CONNECT has been removed already, code snipped was from NCS v2.5.
I only use lte_lc_power_off().

Best,
Kevin

RE: nRF9160 - SYSTEM OFF Mode Current

Charlie — Wed, 22 May 2024 15:46:16 GMT

Hi Kevin,

I worked on a same request three years ago. See https://devzone.nordicsemi.com/support-private/support/261335#permalink=620746.

I will try to adapt it to NCS v2.6.1 tomorrow, but you can also have a try. There are quiet deprecated function and configuration according to nRF Connect SDK v2.6.0 Release Notes — nRF Connect SDK 2.6.1 documentation (nordicsemi.com).

- The lte_lc_init() function is deprecated.
- The lte_lc_deinit() function is deprecated. Use the lte_lc_power_off() function instead.
- The lte_lc_init_and_connect() function is deprecated. Use the lte_lc_connect() function instead.
- The lte_lc_init_and_connect_async() function is deprecated. Use the lte_lc_connect_async() function instead.
Removed the deprecated Kconfig option CONFIG_LTE_AUTO_INIT_AND_CONNECT.

Best regards,

Charlie