Low Power Mode not that low power

[Riaan]

Hi,

I want to enter the NRF52 into a standby low power mode.

I am running sdk17.0.2, with FreeRTOS and softdevice (7.2)

The steps I take are:

1) stop all my threads

2) Setup interrupt to bring out of sleep mode

3) sd_power_system_off();

I can see the current being drawn dip to around 2.5mA to 3mA, but I was hoping for less current.

Is there something else I got to do?

[Susheel Nuguru]

Is this a custom board? that seems to be a lot more current than it should be.

[Riaan]

This is a custom board, but we still got the correct points to measure the individual parts (and we removed all other ones to make sure that it really is the nrf52 drawing the power.

[Susheel Nuguru]

That is strange, It is hard to see what is consuming so much power without knowing what your application is doing.

Is it possible to get your application so that i can get an idea of what it could be? 

Riaan said:

I also do notice that if I don't run FreeRTOS with the RTC I get a bit lower power usage in deep sleep mode.

So without FreeRTOS,which sleep function are you using (WFE or sd_app_evt_wait)?  Are you using BLE (softdevice)?

[Riaan]

We are using the the soft device. Not sure I can give you a copy of the project.

But in short we removed basically all our stuff from the startup routine. We start softdevice, freertos, and then we enter deep sleep.

When we measure the current it seems too high, was expecting sub mA readings.

[Susheel Nuguru]

Have you tested your project on Nordic DK?  does it behave the same?

is it possible to attach your project so that i can do some quick tests on my desk?