Dear colleagues,
with the newer SDK (I am now using NCS v2.5.0 and 2.6.0), I have difficulties finding the right SYSTEM OFF mode current.
Code currently looks like as follows:
#include <zephyr/kernel.h> #include <modem/lte_lc.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; }
Based on:
A) Getting started with current measurements on the nRF9160
and B) NRF9160DK & System OFF
prj.conf was extended to: (does not change anything, I only had the LC layer enabled at first)
# Modem library and link control CONFIG_LTE_LINK_CONTROL=y CONFIG_LTE_AUTO_INIT_AND_CONNECT=n CONFIG_NRF_MODEM_LIB=y
I initially had no modem lib included/function call in the main.c (this was my setup from previous NCS releases, and it worked fine) - but also with the suggested change in the devzone ticket, I don't see a difference. I am measuring 2.7mA.
What is interesting to note though:
If I would erase the flash, and program the *.hex file from the DevZone guide from Stian, I reach about about 400uA. If I then re-erase the flash, and program my code snippet, I end up at the expected current consumption of 1.4uA.
I cannot explain this behavior though, and wonder how I reach the SYSTEM OFF current without flashing the hex file from the devzone guide first.
Thanks,
Kevin