system_off sample for nRF9160 DK

[Canastra]

Hi

I'm locking for an example like zephyr\samples\boards\nrf\system_off for nRF9160 DK

zephyr\samples\boards\nrf\system_off uses nRF51 DK or nRF52 DK board for the demo.

When I test zephyr\samples\boards\nrf\system_off on an nRF9160 DK the nRF Current is alway over 3mA.

Is there a working sample?

[Sigurd]

Hi,

You can see how the SLM application does it here, with the modem_power_off() and enter_sleep() functions:

https://github.com/nrfconnect/sdk-nrf/blob/v1.6.0/applications/serial_lte_modem/src/slm_at_commands.c#L143

[Canastra]

Hi,

I played with the SLM sample.

Now a question to SLM

In the doc to #XSLEEP are three mode

• 0 - Enter Idle. In this mode, the SLM service is terminated, but the LTE connection is maintained.

• 1 - Enter Sleep. In this mode, both the SLM service and the LTE connection are terminated.

• 2 - Power off UART. In this mode, both the SLM service and the LTE connection are maintained.

In Mode 0 I've measured 2-3 uA. Can there be LTE connection maintained?

In Mode 1 I've measured 500 uA. Is this correct for SLM service and the LTE connection are terminated?

In Mode 2 what is the reason to power off the UART and maintained SLM and LTE? I've measured 2-3 uA.

Thanks for support

[Sigurd]

Hi,

Canastra said:

Can there be LTE connection maintained?

 Yes, that seems about right if you are in PSM mode. See this link: https://devzone.nordicsemi.com/nordic/cellular-iot-guides/b/hardware-design/posts/getting-started-with-current-measurements-on-the-nrf9160

Canastra said:

Is this correct for SLM service and the LTE connection are terminated?

 Yes.

Canastra said:

In Mode 2 what is the reason to power off the UART and maintained SLM and LTE? I've measured 2-3 uA.

To save power, having UART on draws power.

[Canastra]

Hi,

We did not understand why a terminated service required more power then a terminated service.

0: SLM service is terminated, but the LTE connection is maintained. -> 2-3uA

1: LM service and the LTE connection are terminated. -> 500uA

2: SLM service and the LTE connection are maintained. 2-3uA

Can you explain this?

What is the lowest power mode?

[Canastra]

Hi,

Sorry typo

We did not understand why a terminated service required more power then a maintained service.

0: SLM service is terminated, but the LTE connection is maintained. -> 2-3uA

1: LM service and the LTE connection are terminated. -> 500uA

2: SLM service and the LTE connection are maintained. 2-3uA

Can you explain this?

What is the lowest power mode?