Bootloader taking higher current consumption upon power on

[Jay_Shah]

Misc info:

1.  SDK Version: v15.3

2.  SD: 6.1.1

3.  Toolchain: IAR v7

I'm trying to use secure_bootloader from the examples but it's taking higher current upon power on. 

Our intention is to integrate the bootloader with the soft device+application but higher current consumption is an issue.

Please check the attached images which we got from PPK.

Can you please help me out on this?

[Kenneth]

The bootloader will do some checksum calculation that take some time during boot,the time will depend on the size of the application, this is a one time operation when chip is powered, and I think it is reasonable to check integrity of the application firmware. You can skip the integrity check for instance when wakeup from system OFF reset:

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v16.0.0%2Flib_bootloader.html&cp=5_1_3_5_0_3&anchor=lib_bootloader_app_start

[asr]

Hi Kenneth,

I did Skip the integrity check ( system OFF reset ) in sdk_config.h file by disabling the below configuration.

// <i> Only CRC checks can be skipped. For other boot validation types, the reset state is ignored.

#ifndef NRF_BL_APP_CRC_CHECK_SKIPPED_ON_SYSTEMOFF_RESET
#define NRF_BL_APP_CRC_CHECK_SKIPPED_ON_SYSTEMOFF_RESET 0
#endif

still I see it drawing higher current.

From the above PPK screenshots, when I do power cycle I noticed that for the duration of around 300ms drawing current about 6-7mA. In the second image about 90ms average current is around 7mA. Can I know what are these bust transactions that we noticed in above PPK screens even after disabling integrity check.

Regards,

asr

[Kenneth]

I notice above that you sometimes do a software reset, and in other cases do a power on reset. If you try a power on reset for all cases, do you measure a difference then?

[asr]

Keneeth,

All the above power measurements that I captured in above ticket are power ON/power OFF button control that present in the nrfConnect Desktop App ( adding PPK  to nrf52 DK ).

[Kenneth]

Can you also try the DFU packet with NO_VALIDATION (skip CRC) for comparison?

[asr]

Sorry for the late response.

Today we tried creating the zip package by adding above mentioned option. But still we see the same behavior as mentioned above.

[asr]

Keneeth,

Do you have any other suggestions that we should try for resolving this issue. This task is marked as high priority. Please help us.

[Kenneth]

I do not quite understand the request. I think it is a sensible recommendation to check the integrity of the firmware upon startup. I do not expect this will have any impact on the life time of the product, can you please explain why this is problematic?

Please also see my previous comment: "

I think we can conclude that it is the way it is in this case. A power cycle it not something we expect happen often, it should really only occur when replacing batteries, in which case doing a integrity check of the firmware make sense.

It could be interesting to know if you have enabled the softdevice in the bootloader and application with the same LFCLK (32kHz clock source).

"