nRF9160 Low Power Example

RE: nRF9160 Low Power Example

RonanB96 — Wed, 21 Aug 2019 12:37:28 GMT

Did you get anywhere with disabling peripherals at runtime?

RE: nRF9160 Low Power Example

GNotman — Wed, 31 Jul 2019 09:17:49 GMT

They seem to have moved the post.

I have updated the answer with the new link.

RE: nRF9160 Low Power Example

Gordon Klaus — Wed, 31 Jul 2019 09:02:08 GMT

What happened to this blog post? It seems to have disappeared.

RE: nRF9160 Low Power Example

GNotman — Wed, 29 May 2019 12:24:54 GMT

Hi Håkon,

I've resolved the issue now.

The guide here helped me. https://devzone.nordicsemi.com/nordic/b/blog/posts/measuring-psm-idle-current-on-the-nrf91-dk

Edit: The guide seems to have moved. It can now be found here:

devzone.nordicsemi.com/.../measuring-psm-idle-current-on-the-nrf91-dk

(Note that for the 0.8.2 DK boards, it is SB44 that needs to be cut.)

I seems that if you removed the USB, the board will draw an additionally, 70-75uAs from the P24 header.

RE: nRF9160 Low Power Example

GNotman — Tue, 28 May 2019 10:18:44 GMT

Thank Håkon,

The lowest I have been able to see idle is with a modified version of the SPM example.

I'm using the nrf SDK v0.4.0 tag with a 0.8.2 DK, powered through P24 with SB44 cut.

The project has one configuration change Device Drivers->Serial Drivers has been unchecked.

Code has been modified with the following diff:

diff --git a/samples/nrf9160/spm/src/main.c b/samples/nrf9160/spm/src/main.c
index fa41616..f02e8fd 100644
--- a/samples/nrf9160/spm/src/main.c
+++ b/samples/nrf9160/spm/src/main.c
@@ -5,6 +5,7 @@
*/

#include <spm.h>
+#include <kernel.h>

/*
* Example code for a Secure Partition Manager application.
@@ -52,6 +53,7 @@

void main(void)
{
+ while(1) k_sleep(1000);
spm_config();
spm_jump();
}

Average current is 83.3uAs over a 30s sample.

I did get some direct support yesterday (after I created the above reply), which seems to indicate that I the issue is with using a 0.8.2 DK.

RE: nRF9160 Low Power Example

Håkon Alseth — Tue, 28 May 2019 08:23:23 GMT

Hi,

[quote user="GNotman"][/quote]

I'm still stuck here with the original problem.

The best I have been able to achieve is about ~80uAs. That is with just SPM which goes straight to idle/sleep (before configuring or jumping).

I've tried this with two separate DKs both 0.8.2 using the latest 0.7.29-alpha firmware and with the SB44 mod.

Could you share your project so I can try to recreate it at my end?

Kind regards,

Håkon

RE: nRF9160 Low Power Example

GNotman — Mon, 27 May 2019 11:24:06 GMT

Hi Hakon,

I'm still stuck here with the original problem.

The best I have been able to achieve is about ~80uAs. That is with just SPM which goes straight to idle/sleep (before configuring or jumping).

I've tried this with two separate DKs both 0.8.2 using the latest 0.7.29-alpha firmware and with the SB44 mod.

RE: nRF9160 Low Power Example

isurki — Mon, 27 May 2019 10:01:18 GMT

Hi Håkon,

I tried with the latest modem fw, and the latest release (v 0.4.0) And I get the same current value. I can't get lower than 20uA (it fluctuates between 20uA and 30uA).

I'm just starting with the DK, and maybe this question has an ovbious answer, but it is possible to comunicate with the modem even with the uart disabled? We need to be able to open a comunication socket with the modem every certain time to ge some data.

I'll open another case to ask for help with my specific use-case.

Kind regards,

Ainara

RE: nRF9160 Low Power Example

Håkon Alseth — Mon, 27 May 2019 09:00:00 GMT

Hi Ainara,

Could you try this with the latest modem fw (mfw_nrf9160_0.7.0-29.alpha)?

It should allow the eSIM to be turned off during PSM, allowing you to go to the lowest power mode, which will be approx. 7 uA (on engineering silicon) if the application does not start any peripherals requiring the HFCLK.

[quote user="isurki"]We need to shut down almost everything from the board for 15 minutes, then read an analog input, and look for any mesages in the modem.[/quote]

If you have questions/issues implementing your specific use-case, I'd recommend that you create a new case with the specific details.

Kind regards,

Håkon

RE: nRF9160 Low Power Example

isurki — Thu, 23 May 2019 08:56:18 GMT

hi Håkon,

Thanks for the response. We need to shut down almost everything from the board for 15 minutes, then read an analog input, and look for any mesages in the modem.

How can I turn off the modem so I can get a lower current measurement? The current consumption has to be as low as possible during those 15 minutes I talked about, since the system is supposed to be powered by batteries.

Kind regards,

Ainara

RE: nRF9160 Low Power Example

Håkon Alseth — Thu, 23 May 2019 07:02:48 GMT

Hi Ainara,

[quote user="isurki"]I've followed this thread and I'm able to reduce the current down to 35uAs.[/quote]

If you are seeing around ~30 uA, this is likely due to the SIM clock stop. At this moment it is not possible to fully shut down the SIM, so you will have this floor current when the modem is active.

[quote user="isurki"]I need to shut down all peripherals for a periode of time, and after that time has passed, I need to wake some of them up to use them. I don't know if there is a way or not.[/quote]

What peripheral do you need to shut down?

Kind regards,

Håkon

RE: nRF9160 Low Power Example

isurki — Tue, 21 May 2019 12:12:34 GMT

Hi Håkon!

I've followed this thread and I'm able to reduce the current down to 35uAs. but disableing the uart trhow the conf file. Is there any other way to disable any peripherals while running the aplication? I need to shut down all peripherals for a periode of time, and after that time has passed, I need to wake some of them up to use them. I don't know if there is a way or not.

I would appreciate your help,

kind regards,

Ainara

RE: nRF9160 Low Power Example

isurki — Fri, 10 May 2019 10:07:45 GMT

Hi!

I would appreciate your help,

kind regards,

Ainara

RE: nRF9160 Low Power Example

GNotman — Fri, 12 Apr 2019 11:25:22 GMT

Hi Håkon,

I had some more time to work on this finally.

Yesterday, I was able to reduce the current down to ~120uAs (@3.75V) when powered through the P24 header.

This was done by adding both of the following lines to the 'secure_boot' prj.conf file.

CONFIG_UART_CONSOLE=n
CONFIG_SERIAL=n

Previously, I had reported that adding only the 'CONFIG_SERIAL=n' caused the bootloader to fail and not to load the application.

Also I believe the differences in our measurements are likely due to the SB44 mod to remove the leakage from U25.

RE: nRF9160 Low Power Example

Håkon Alseth — Mon, 04 Mar 2019 15:28:09 GMT

Hi,

[quote user="GNotman"]The first image shows an average current of ~860uAs between the eDRX paging windows[/quote]

As you're using a more accurate AM-meter than I am, I'll trust your base current better than mine. My cheap am-meter shows approx. 1.0 - 1.2 mA between the wake up's.

Something is powered during these events that shouldn't be powered. As mentioned, we are actively looking into this issue internally.

[quote user="GNotman"]The second image is after using (CONFIG_SERIAL=n) with secure_boot and the same modified version of asset_tracker as used above. It is clear that the boot loader fails to load the main firmware:[/quote]

Try cleaning your build directory after changing any configuration in the project file. Not sure what happens here, but it looks like a fault given the constant current consumption.

If you are in debug mode, it might be this errata: https://www.nordicsemi.com/DocLib/Content/Errata/nRF9160_EngA/latest/ERR/nRF9160/EngineeringA/latest/anomaly_160_17

Kind regards,

Håkon

RE: nRF9160 Low Power Example

GNotman — Mon, 04 Mar 2019 10:49:49 GMT

Hi Hakon,

Here is the output from the profiler I am using.

The first image shows an average current of ~860uAs between the eDRX paging windows. You can also see the initial registration activity and the regular eDRX paging windows:

The second image is after using (CONFIG_SERIAL=n) with secure_boot and the same modified version of asset_tracker as used above. It is clear that the boot loader fails to load the main firmware:

RE: nRF9160 Low Power Example

Håkon Alseth — Mon, 04 Mar 2019 07:52:42 GMT

Hi,

In order to enable PSM/eDRX, you have to wait a given amount of time before its registered in the network. This can take some seconds (didn't measure, but took maybe 10-20 seconds?), where the power consumption should be lowered after that. As mentioned, we seem to have issues in the way we enable PSM/eDRX in our sources, as I am not able to get below 1 mA area.

Kind regards,

Håkon

RE: nRF9160 Low Power Example

GNotman — Fri, 01 Mar 2019 09:50:00 GMT

I'm afraid adding (CONFIG_SERIAL=n) to secure_boot/prj.conf does not help in fact it seems to break something. The power profile now just shows a steady 9.55mAs. Normally, the power profile shows a lot of initial activity followed by a lower power state with regular brief spikes (watchdog?).

RE: nRF9160 Low Power Example

Håkon Alseth — Fri, 01 Mar 2019 08:44:43 GMT

You need to disable serial (CONFIG_SERIAL=n) in both secure_boot and the non-secure application in order to achieve low consumption in sleep.

As mentioned, I also see a high current consumption after requesting PSM/eDRX, so there's something fishy in our process of enabling PSM/eDRX. I have highlighted this issue internally, and it will be looked at in the upcoming weeks.

RE: nRF9160 Low Power Example

GNotman — Thu, 28 Feb 2019 16:37:41 GMT

Hi Håkon,

I have tried your modifications from below but I'm still not seeing anything under about 880uAs. I have configured the device to use eDRX and I am able to see the paging events clearly in the power profile at the configured intervals. However, between the paging windows the current is a pretty constant ~880uAs.

Is there something I'm missing with regards to getting the device down to ~30uAs?

Software setup:

Repositories (checked out tags are per the setup guide):

nfxlib & nrf -> v0.30
mcuboot & zephyr -> v1.3.99-ncs2

Modifications:

secure_boot/prj.conf modifications:
- CONFIG_UART_2_NRF_UARTE=n
asset_tracker/prj.conf modifications using your diff from below.
asset_tracker 'main' function starts with -> modem_configure(); while(1) k_sleep(1000);
asset_tracker autoconf.h modifications:
- Added: #define CONFIG_LTE_EDRX_REQ 1
- Modified: #define CONFIG_LTE_EDRX_REQ_VALUE "0100" // ~61s eDRX interval
zephyr/scripts/kconfig/kconfig.py USE_AT_HOST added whitelist.

Hardware setup:

Powered (and profiled) through the P24 header.
SB44 has been cut.

p.s. I have also tried skipping the modem_configure() call in at the start of the main function, this did not make any difference.

RE: nRF9160 Low Power Example

Håkon Alseth — Wed, 27 Feb 2019 14:52:20 GMT

That sounds similar to what I am seeing.

To check the idle current, add this to the top of the main function:

while(1) k_sleep(1000);

The program will then just enter sleep after initializing all drivers/libs. This should be around 30 uA (due to SIM clock stop) if all UARTs are disabled properly.

Here's the prj.conf diff I used: devzone.nordicsemi.com/.../prj.diff

With the default settings at my end it stabilizes to ~1.5 mA.

The current examples are not power optimized, and the release notes for the modem states this:

- nRF9160 power consumption has not been fully optimized.

Kind regards,

Håkon

RE: nRF9160 Low Power Example

Étienne Castanié — Wed, 27 Feb 2019 13:34:13 GMT

Thank you for your quick answer! We'll make sure to stay updated and keep using the latest master branch of this repo.

Regarding the asset_tracker example, it runs fine on our board. Unfortunately, when we activate PSM on asset_tracker and that we disable uart on both secure boot & asset_tracker, the current consumption is never lower than 1mA and can randomly spikes to 20 mA.

Best,

Étienne

RE: nRF9160 Low Power Example

Håkon Alseth — Wed, 27 Feb 2019 11:22:01 GMT

Hi Étienne,

I'd recommend that you watch the github repo in order to stay updated on samples/applications:

https://github.com/NordicPlayground/fw-nrfconnect-nrf

As mentioned, you can still enable PSM/eDRX in asset_tracker (see readme.rst), but the sample secure_boot and asset_tracker has serial enabled (CONFIG_SERIAL and CONFIG_BSD_LIBRARY_TRACE_ENABLED) which needs to be disabled in order to keep the floor current low.

Kind regards,

Håkon

RE: nRF9160 Low Power Example

Étienne Castanié — Wed, 27 Feb 2019 09:30:29 GMT

Dear Håkon,

We are also trying to evaluate the nrf9160 DK low power level with regular PSM-sent communications with a server.

Is there a way for us to be notified (by email or other preferred means) when such an example (PSM or eDRX) will be available from Nordic?

Thank you very much for your help.

Best,

Étienne

RE: nRF9160 Low Power Example

Håkon Alseth — Thu, 14 Feb 2019 19:11:17 GMT

Hi,

[quote user=""]I have tried profiling the at_client sample, but the lowest I've manged with the nRF9160DK is about 900uAs.[/quote]

Most of this is due to the UART RX being enabled, which will keep the peripheral clock tree running in sleep. Disabling the UART will lower the floor current, but will also make this specific example non-working.

[quote user=""]Is there any low power example, or documentation which can help me with this?[/quote]

Unfortunately, we do not have a power optimized example showing the lowest consumption possible at this stage in the engineering phase. The closest is the asset_tracker example, where you can enable power optimization (PSM or eDRX), but you will also need to tweak other parts, such as disabling serial in both secure_boot and the application itself.

Kind regards,

Håkon