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,

Sorry, I have not worked with SPM for a while and I need to set up the environment for NCS 1.9.0 for this request and will come back to you next week.

You can have quick try by copy content in prj_minimal.conf replace the configuration in prj.conf of sdk-nrf/samples/spm at v1.9-branch · nrfconnect/sdk-nrf (github.com) sample then rebuild the whole project.

The theory behind is introduced in the following pages: (+) Using a custom Secure Partition Manager with your application - Software - nRF Connect SDK guides - Nordic DevZone (nordicsemi.com)

Best regards,

Charlie

[Wesley14]

Hi Charlie,

That's perfectly fine. I will continue to investigate using the resources you provided.

Regards,

Wesley

[Wesley14]

Hi Charlie, Any update on this query?

Regards,

Wesley

[Charlie]

Hi Wesley,

Sorry, I will borrow a Linux PC to try now. Does it mean your test with prj_minimal.conf not work at all?

Best regards,

Charlie

[Wesley14]

No it did not unfortunately

[Charlie]

I add "CONFIG_SERIAL=n" to v1.9.0\nrf\samples\spm\prj.conf then the log output for SPM is disabled.

[Wesley14]

Hi Charlie,

Sorry for the late response and I appreciate the feedback you've given. Came back to this project and even though the output is disabled, the text (from the image at the top of this chat) still appears even after changing CONFIG_SERIAL to n. The current still drops to 440uA instead of the intended 2-4uA.

[Wesley14]

Please advise on any alternate solutions or methods I could try.

Regards,

Wesley

[Charlie]

Hi Wesley,

I did the following change to the original GNSS sample. Set it to period GNSS modem with default 120s interval and 20s timeout.

You can see the PPK recording shows it reach to floor current when timeout or GNSS fix happen.

chs1@csh1 MINGW64 /c/NCS/v1.9.0/nrf/samples/nrf9160/gnss ((v1.9.0))
$ git diff --cached
diff --git a/samples/nrf9160/gnss/child_image/spm.conf b/samples/nrf9160/gnss/child_image/spm.conf
new file mode 100644
index 000000000..72a7d45fe
--- /dev/null
+++ b/samples/nrf9160/gnss/child_image/spm.conf
@@ -0,0 +1 @@
+CONFIG_SERIAL=n
\ No newline at end of file
diff --git a/samples/nrf9160/gnss/prj.conf b/samples/nrf9160/gnss/prj.conf
index 9a81e3ed0..ce5a385c0 100644
--- a/samples/nrf9160/gnss/prj.conf
+++ b/samples/nrf9160/gnss/prj.conf
@@ -45,3 +45,8 @@ CONFIG_NET_NATIVE=n
 CONFIG_HEAP_MEM_POOL_SIZE=2048
 CONFIG_MAIN_STACK_SIZE=4096
 CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=1536
+
+
+CONFIG_GNSS_SAMPLE_MODE_PERIODIC=y
+CONFIG_GNSS_SAMPLE_PERIODIC_TIMEOUT=20
+CONFIG_SERIAL=n

Best regards,

Charlie