Too much power consumption in mesh, light_control example

[Jake]

In my test, light_control example consumes about 17mA, same for both of client and server.

I'm using nRF52DK, PCA10040, and SDK is "nrf5_SDK_for_Mesh_v0.9.2-Alpha". I measured power consumption from "nRF current measurement" pins in nRF52DK board.

I think 17mA is too much.

Is there any point to make power consumption lower?

[Jørgen Holmefjord]

Hi Jake,

The Bluetooth Mesh is based on scanning and broadcasting. This will keep the radio active most of the time, causing high current consumption.

I see the same numbers of ~17 mA on the examples. The simplest thing you can do to decrease the current consumption when running on the nRF52 DK (PCA10040) board, is to enable the DCDC regulatior. This can be doen by adding NRF_POWER->DCDCEN = 1; to the start of main() (before mesh initialization), or by adding sd_power_dcdc_mode_set(NRF_POWER_DCDC_ENABLE); before the while loop inside main() (after mesh initalization). This should reduce the current consumption to ~9 mA.

Best regards,

Jørgen

[Jake]

Dear Jørgen

Thank you for your reply. "NRF_POWER->DCDCEN = 1;" is working. It reduced to 9.5mA. But, 9mA is still too much.

Do you have an idea or an example to implement Low Power Mode, which consumes below 1mA?

Best Regards, Jake

[Jørgen Holmefjord]

I think you will have a hard time reaching less than 1 mA with the current Mesh SDK. As noted in the release notes, both scanning and advertising interval is configurable up to 10240 ms, but note that configuring this at high values might make the mesh slow or unreliable. There is a Low Power node defined by the specifications, but this have not yet been implemented. This will allow end nodes in the mesh to go to sleep for a period of time, and request updated data from a friend node whenever it wakes up. You can read more about this in the power consumption section on this page, or in the Bluetooth Mesh specifications.