mesh bootloader for low power device

[ThomasH]

Hi

We are using this combination of software:

• Mesh SDK 4.2
• Bluetooth SDK 17.0.1
• Softdevice 7.0.1
• Mesh DFU using the precompiled bootloader binary mesh_bootloader_gccarmemb_nrf52840_xxAA.hex

We develop a low power device which can also be powered by external supply. When externally powered we want to update the devices. Therefore we are using DFU. In principle it works and we can update the application so far.

Problem:  When gooing to sleep the bootloader consumes nearly 400uA. (without bootloader the application needs about 7uA)

Questions:

• How can I manage to bring the bootloader to low power mode?

Best regards

Thomas

[Joakim Jakobsen]

Hi.

As you can see from my colleague Terje's answer here:
https://devzone.nordicsemi.com/f/nordic-q-a/54868/how-to-reduce-the-power-consumption-of-the-bootloader

The Mesh bootloader is not recommended, as it requires the node to be always on. If you have the devices on external power supply during update, I guess power consumption isn't an issue?
Anyways, if you want to save power and perform DFU on low power devices (or Low power node, LPN) you should follow Terjes suggestion.

Br,
Joakim

[ThomasH]

Dear Joakim

Actually we need to use the mesh bootloader - and some of our devices also need to go to sleep.

From the tickets I concluded that some time ago there was a mesh bootloader not having the low power issue. Am I wrong?

I'm aware that for DFU the device has to be powered externally.

In the ticket you referenced there is a reference to an other ticket with the same problem.In both tickets there is a bugfix which should solve the issue.

Could you please explain me what I have to modify in the source code of the mesh bootloader solve my issue?

Br,

Thomas

[ThomasH]

Dear Joakim

we solved the problem by doing the modifications in the bootloader source code.

You can close this ticket.

Br,

Thomas

[Joakim Jakobsen]

Thanks for letting me know.

Br,
Joakim