nrf9160 idle current consumption ~500μA

RE: nrf9160 idle current consumption ~500μA

nexus — Mon, 08 Nov 2021 12:14:00 GMT

Hey Simon

Thanks for pointing this out. This makes much more sense. I am realizing this is also the case in the UDP example of the nrf91. I will update my post accordingly. Thanks again!

RE: nrf9160 idle current consumption ~500μA

Simon — Mon, 08 Nov 2021 12:06:03 GMT

Thanks for sharing your solution! Another way of going about this is to add CONFIG_SERIAL=n to the file <application>/child_image/spm_prj.conf like done in <..>/asset_tracker_v2/child_image/spm/prj.conf.

RE: nrf9160 idle current consumption ~500μA

nexus — Mon, 08 Nov 2021 11:57:43 GMT

Thanks for this hint, it helped me a lot to drill down the power issue I was seeing. I also measured about 520 uA for the blinky example until I realized the CONFIG_SERIAL flag needs to also be disabled in the spm module.

I have written up a tiny howto over here explaining how to replicate the issue and solve it:
High Idle Power Consumption on the NRF9160 DK using Blinky on Zephyr (~ 520 uA)

For configuring spm I found the following menuconfig command helpful:

west build -b nrf9160dk_nrf9160_ns -t spm_menuconfig

RE: nrf9160 idle current consumption ~500μA

Niovi.sass — Wed, 23 Jun 2021 14:05:16 GMT

Thanks again, this helped me a lot!

Best regards,

Niovi.

RE: nrf9160 idle current consumption ~500μA

Simon — Wed, 23 Jun 2021 13:55:57 GMT

[quote user="Niovi.sass"]What I miss is why the USB cable is required during the measurement. Isn't the chip powered by the P24 connector?[/quote]

You have to power the rest of the DK with USB, such that the cables from the debugger has the correct level. SWD interface, and the nRESET pin and UART if it's in use. The options is to cut SWD and nRESET using solder bridges. .

RE: nrf9160 idle current consumption ~500μA

Niovi.sass — Fri, 18 Jun 2021 13:03:54 GMT

Thanks for the response.

What I miss is why the USB cable is required during the measurement. Isn't the chip powered by the P24 connector?

I also tried to measure the current with Otii Arc (power analyzer):

with 3.7V the result was 79.5μA :

and with 3V the result was 95.9μA :

Thanks in advanced.

Best regards,

Niovi.

RE: nrf9160 idle current consumption ~500μA

Simon — Fri, 18 Jun 2021 11:37:51 GMT

In the image I didn't see any USB cable plugged in, make sure that is the case when you're measuring.

The voltage output on the LCD screen is 3V, which is a little low, but it should work.

Are you able to measure the current using another measurement setup and see if you get the same result then?

RE: nrf9160 idle current consumption ~500μA

Niovi.sass — Fri, 18 Jun 2021 06:50:31 GMT

Thank you for your reply. I tried and measured a current of ~90μΑ better than 500μΑ but still not 7μA.

Thanks in advanced,

Niovi.

RE: nrf9160 idle current consumption ~500μA

Simon — Thu, 17 Jun 2021 12:05:47 GMT

Try to cut SB44 and follow the guide by Bjørn here (which covers the setup for older nRF9160 DKs): https://devzone.nordicsemi.com/f/nordic-q-a/42387/instructions-for-setting-up-9160-dk-for-current-measurement-are-confusing/166460#166460

[quote user="Niovi.sass"]Also two weeks ago I upgrade to MFW 1.3.0 and downgrade again back to mfw 1.2.0 because the device is Revision 1 and as far as I understand it is not compatible . Could this be the reason for not getting the right current measurement ?[/quote]

Modem fw 1.3.0 works with rev1, but that combo will not get certified with any operators. When you transition from 1.3.0 to 1.2.x, you loose all the certificates that are stored in the modem, so we don't recommend doing so. However, this should not affect the current consumption, as far as I know, I think that 1.3.0 uses less current.

Best regards,

Simon

RE: nrf9160 idle current consumption ~500μA

Niovi.sass — Wed, 16 Jun 2021 15:22:06 GMT

Thank you for the response. I built and flash my application and slide switch SW10 to the EXT position to disable switch U25.

Also two weeks ago I upgrade to MFW 1.3.0 and downgrade again back to mfw 1.2.0 because the device is Revision 1 and as far as I understand it is not compatible . Could this be the reason for not getting the right current measurement ?

Thanks in advanced.

Best regards,

Niovi

RE: nrf9160 idle current consumption ~500μA

Simon — Wed, 16 Jun 2021 11:46:15 GMT

I built and flashed your sample using west build -b nrf9160dk_nrf9160ns && west flash and I measured a current of 7.57uA using the PPK2 and an nRF9160DK v0.8.2. I measured a current of 6.61uA using an nRF9160DK v0.9.0. I don't have a v0.8.3 at hand at the moment.

I also tested the system off hex file from Getting started with current measurements on the nRF9160, and measure a current of 6.23uA, which is not as low as the system OFF current in the product specification for some reason, but at least not 500uA.

Could you explain your measurement setup in more details.

RE: nrf9160 idle current consumption ~500μA

Simon — Tue, 15 Jun 2021 15:21:03 GMT

Thanks. I'll take a look at it tomorrow.

RE: nrf9160 idle current consumption ~500μA

Niovi.sass — Tue, 15 Jun 2021 13:21:07 GMT

Thanks for the response. In both files <sample>/build/zephyr/.config and <sample>/build/spm/zephyr/.config said

# CONFIG_SERIAL is not set.

Here is my application.
devzone.nordicsemi.com/.../2744.test.zip

Thanks in advanced,

Niovi.

RE: nrf9160 idle current consumption ~500μA

Simon — Tue, 15 Jun 2021 12:37:15 GMT

Can you upload the files <sample>/build/zephyr/.config and <sample>/build/spm/zephyr/.config, then we can see what Kconfigs are actually being set. It would be interesting to see if CONFIG_SERIAL=y is set in any of them. If you have more child images, can you check the .config of them as well (e.g. <sample>/build/mcuboot/zephyr/.config)?

If the .config's looks fine, would you be able to zip your application and send it over? Then I'll test it on my nRF91 DK.

Best regards,

Simon