How to reduce the power consumption of the bootloader?

[ZHENGXIANG]

Hello:

When I try to use mesh, I found that the bootloader never work in low power mode. If I only program application into the nrf52832, the power consumption of its low power mode is about 10 uA. When I add bootloader, its power consumption is more than 200 uA. What can I do to reduce the power consumption of the bootloader part？I want to make the whole power consumption less than 50 uA. 

Moreover, if I only need the function of DFU in bootloader, which part of the bootloader in mesh can I delete?

Thank you

[tesc]

Hi,

Is this for a low power node (LPN)? In that case, the mesh DFU bootloader is not recommended, as it requires the node to be always on. For LPN we recommend using the GATT based DFU solution from nRF5 SDK instead. The Low Power node example supports DFU from nRF5 SDK, see Configuring DFU over BLE using the LPN example.

Regards,
Terje

[ZHENGXIANG]

Hi:

Thank you for your response. This question is not for a LPN. It focus on why the bootloader part still work when the applicaion sleep. I have asked this question last week in Nordic Tech Tour and got official answer: this is a bug for nRF5 SDK for Mesh and they will fix it in next version.

Thank you

[Jui-Chou (Rick) Chung]

Hello ZhengXiang,

Just want to confirm one thing, if your mesh device is not connected with PC, then you should choose the bootloader which without serial interface enabled, like "mesh_bootloader_gccarmemb_nrf52832_xxAA.hex", not the "mesh_bootloader_serial_gccarmemb_nrf52832_xxAA.hex"

And I did a check, we found the issue from the ticket:

https://devzone.nordicsemi.com/f/nordic-q-a/43301/nrf_mesh_disable-function-changed-since-sdk-for-mesh-v3-1-0

You can try the workaround described in the above link, and now our internal RD fixed the issue and waiting for the code review. I will update this ticket once when I got the response from internal about when will we release the fix. Hope this information can do help.

Best regards,

Rick

[ZHENGXIANG]

Hi:

I have tried this but it does not work. The gpio is still open. Now I just delete the uart0 and gpio part in serial_handler_uart.c and add 

NRF_CLOCK->TASKS_HFCLKSTOP=1;
NRF_UART0->TASKS_STOPRX= 1;

in main.c in bootloader.

Now it can work and the power consumption is about 15uA.

Thank you