nRF9160 Low Power Example

[GNotman]

Hi,

I'm currently trying to evaluate the nRF9160 for one of our projects.

One key requirement is the power consumption when using eDRX.

I have tried profiling the at_client sample, but the lowest I've manged with the nRF9160DK is about 900uAs.

Additionally, the power profile does not seem to show the expected paging windows when eDRX is configured.

Is there any low power example, or documentation which can help me with this?

[Håkon Alseth]

Hi,

 

GNotman said:

The first image shows an average current of ~860uAs between the eDRX paging windows

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.

GNotman said:

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:

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

[GNotman]

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.

[isurki]

Hi!

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

[isurki]

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

[Håkon Alseth]

Hi Ainara,

  

isurki said:

I've followed this thread and I'm able to reduce the current down to 35uAs.

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.

 

isurki said:

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.

What peripheral do you need to shut down?

Kind regards,

Håkon