Unable to add system off sleep mode in zephyr

[SM_]

Hi,

I am new to zephyr. 

I have tested Ibeacon and System off example individually on nrf52840 PDK board.

I am trying to add system off (Deep Sleep) mode in the zephyr Ibeacon example. 

for that simply I have added the header files of system off example in the Ibeacon example and the below two lines

pm_state_force(0u, &(struct pm_state_info){PM_STATE_SOFT_OFF, 0, 0});

k_sleep(K_SECONDS(SLEEP_S));

in main of Ibeacon example. 

such that after Ibeacon function execution the system off is executed and remains in it.

but I am not getting the expected results as I check the power consumption of the board using the PPK 1 board, it shows 400 - 600uA.

Please help me to resolve this issue or please share any link of sample example related to this. 

[Hung Bui]

Hi Sunil, 

I couldn't reproduce the issue you described. 
Please test with the following sample. The device will advertise for 5 seconds before enter deep sleep (current consumption down to around 1uA). NCS v2.1.1 
You can consider put CONFIG_SERIAL=n to put the consumption lower, but it wouldn't affect the deep sleep current. 

peripheral_hrSystemoff.zip

[MTR]

Dear Hung Bui,

I tested this sample on nrf52840 chipset (Skylab skb501 module) on a custom board. There is nothing but the BLE module on board. 

The current consumption is 1 mA. 

Do you have any idea?

[Hung Bui]

Hi MTR,

1 mA is not normal.

Do you have a nRF52 DK to cross check ? 

Could you try testing with system_off sample  ? You should see around 1uA when the device in system off. 

[MTR]

I know it is not normal.

No I don't have other nRF52 DK.

I tried system_off but it does not reach 1uA. the least current I reached was 350uA.

I have another board with NRF52832 , with that the current reached 600uA.(with Keil+softdevice)

[Hung Bui]

Please try to isolate the chip on your board. Cut off any peripheral to make sure you are measuring only the NRF52

When measuring please disconnect any UART or RTT logging or SWD debugging. 

[MTR]

Thank you for reply,

I've done all of them.

I mounted just BLE module with  capacitors only.

I got the same result,1 mA.

By disconnecting JTAG it reduced 10-20 uA!

Is it a possibility of hardware problem?Or the custom board definition which I defined in VScode for zephyr?

[Hung Bui]

Hi MTR, 

Please create  a new ticket for your case. 
We are not so sure what could be the problem. Have you tried to test on multiple module or only one module ? 
I assume what you meant by "reduced 10-20uA" is that it's still close to 1mA and just dropped 10-20uA from that , correct ? 
Please reply in the new case and not continue in this.