Low Power mode using GNSS sample code with nRF9160 DK

[Wesley14]

Hi,

I am investigating low power modes in the nRF9160. I am currently using the GNSS sample code and getting around 36mA. Is there any way to configure the base code to achieve a much lower current? Ideally, I want to drop the current from mA to uA if possible.

I only need the GNSS sample code to basically locate my device every 2 hours

So, my main questions are:

How do I activate low power or sleep mode in the nRF9160?

How can I configure the GNSS sample code to achieve low current consumption?

Thanks

[Charlie]

Hi Wesley,

Thanks for checking with us this request. You can start with the following blog, it basically covers your two questions.

(78) Up to 4x battery life: The benefits of assisted GPS in asset tracking - Blogs - Nordic Blog - Nordic DevZone (nordicsemi.com)

Let me know if you have more questions.

Best regards,

Charlie

[Wesley14]

Thank you, Charlie, for the response. The blog definitely helped. One more concern I have is with regards to the "Booting Zephyr OS" message that appears in the serial terminal. Below is an image displaying the issue.

My question is, how do I stop this message from displaying?

I am using SDK 1.9.0.

I have changed the following as well, but the message still appears:

CONFIG_SERIAL=n

CONFIG_UART_SERIAL=n

CONFIG_SECURE_BOOT_DEBUG=n

CONFIG_LOG=n

Thanks

[Charlie]

Hi Wesley,

If you just start your development, I strongly suggest you switch to the latest NCS version(NCS 2.6.1 now and NCS 2.7.0 will be released next week)+MFW 1.3.6.

NCS 1.x and 2.x has a big change on security management, you would not have this displaying when you switch from SPM to TF-M (introduced since NCS 2.0.0).

Migration notes for nRF Connect SDK v2.0.0 (nordicsemi.com)

Running applications with Trusted Firmware-M (nordicsemi.com)

Trusted Firmware-M Documentation (nordicsemi.com)

Let me know if you still have to work with NCS 1.9.0 or not.

Best regards,

Charlie

[Wesley14]

Thank you for the timely response. For my investigation, I have to work with 1.9.0

Regards,

Wesley

[Charlie]

Ok, you can refer to the spm.conf configuration in SLM sample. It disables the log output from SPM.

sdk-nrf/applications/serial_lte_modem/child_image/spm.conf at v1.9-branch · nrfconnect/sdk-nrf (github.com)

[Wesley14]

Hi Charlie, thanks for this site. I have tried to implement the same configurations for the GNSS sample code but still had no luck.

I have to work with the GNSS sample and with SDK 1.9.0 due to this being a product for the NETSTAR customer. Your responses are appreciated.

The nRF9160 with the GNSS sample code consumes 36mA and then drops to around 440uA as expected. If I am able to disable all debug in the serial terminal, then this should drop the current to 2uA-4uA which is my intended goal.

Regards,

Wesley