NRF52832 DK --PCA10040 current measurement

[Astor]

Hi,

I'm evaluating BLE power consumption with a PCA10040 nRF52DK and a PPK, I cut SB9 and did nothing else with DK.

No peripheral is used in projects, Buttons or LEDs, but I got 18uA idle current after 1minute. Before which idle current is above 200uA, but anyway it exceeded the value written on specification.

Could I have any suggestion how to measure the current with nRF52DK and PPK?

Also I will use an Agilent 66319 power analyzer for formal measurement, but nothing was mentioned in nRF52 handbook. Please also help on it, thanks a lot.

[Stian Røed Hafskjold]

Hi, can you try to run ble_app_pwr_profiling instead? It is power optimized and has logging disabled by default. It starts out in system OFF mode and you should see < 1 uA consumption.

Other than that, you need to make sure that logging is disabled in the examples you are running (NRF_LOG_ENALBED=0 in sdk_config.h)

Are you using PPK1 or PPK2? In ampere meter mode or SMU mode?

[Astor]

Hi, will do later. FYI, we are develop a low power device that is advertising all day and awaits connection.

So we need to find out how long it can survive with battery. That's why we chose the blinky app.

We care nothing about System Off mode and all we will run is BLE + System ON mode.

So it will be really kindly of you to guide us directly how to measure the power consumption(current) with an advanced power supply, which provides stable voltage and measures the current through the power supply.

Thanks

[Stian Røed Hafskjold]

Yes, that's exactly what the ble_app_pwr_profiling is doing. It starts out in system OFF mode, so you can verify the measurement setup. Then you push button 1, and it will start advertising, waiting for a connection. It is meant for power profiling normal BLE applications.

The blinky app is not power optimized because it has logging enabled.

If you want to power the nRF52 DK from a SMU (source measure unit, i.e. advanced power supply, which provides stable voltage and measures the current through the power supply.) you will have to power the + wire on the current measurement header, P22, and the - wire on one of the GND connections. And, set the output voltage to match the DK voltage exactly. It should be around 2.7V. Also, leave the USB cable plugged in to power the rest of the board.

If you want to calculate the life time of your application, you can use the online power profiler

[Astor]

Thank you Stian, I think I missed the step to leave the USB cable plugged in. Will follow your suggestion and test with ble_app_pwr_profiling.

Really helped, thanks alot

[Astor]

Hi, while testing with PPK, ble_app_pwr_profiling has great current and unknown behavior(without press any button now).  Minimum current is about 160 uA.

I just connect PPK and DK together with SB9 cut. Softdevice version 7.2.0, SDK version 17.0.2

[Stian Røed Hafskjold]

Hi, is it working when you do not connect the PPK together with the DK? How do you connect the PPK, and are you using the PPK1 or PPK2?

[Astor]

The application performs normally no matter it's connected to PPK or not (press button and starts advertising). But the current doesn't meets expectation.

I'm using PPK1 exactly same as described in user guide(perhaps):

[Stian Røed Hafskjold]

Hi, I tried it out here, and it looks like the PPK1 is not working well with the newest software updates. I get the same noise and about 100uA in system OFF mode. I checked with a power analyzer and it looks normal, so it's definitely something wrong with PPK1. I will have to check with the developers. Sorry for the inconvenience. I would recommend to get the PPK2, as the PPK1 is now a deprecated product.