LPN power profile

[jowei]

Hi Nordic

I am using mesh-sdk-4.0 LPN example on PCA10040, 

After provision the LPN, I didn't press any button(means no send onOff packets, no establish friendship), just using PPK to measure the current, that's means LPN will broadcast proxy every 2 seconds.

But I find there is another periodic current consumption for every 10 seconds, this periodic is similar every 5 proxy packets in the beginning, and has some timing shift to the every 5th proxy packet later.(see following to pictures)

Is this also polling? or what is the action cause the current consumption?

Thanks

[Simonr]

Hi

Do you know what LF clock source you are using? If you're using the internal LFRC oscillator, this seems likely as I don't see these 10-second spikes when measuring here on my end.

Best regards,

Simon

[jowei]

Hi simon:

I am using LPN example of mesh-sdk-4.0 + sdk16, no any modification 

so in sdk_config.h, NRF_SDH_CLOCK_LF_SRC=1, NRF_SDH_CLOCK_LF_ACCURACY = 7

My PPK is using DK's power.

Do you provision your LPN and disconnect mobile APP to LPN?  And don't establishing friendship.

Joseph

[Simonr]

Hi Joseph

I was testing on an nRF52840, where these spikes were almost unnoticeable for some reason. When testing on an nRF52832 myself I was able to recreate what you're seeing as well. I haven't been able to figure out what these current spikes are as of yet though, so I have now contacted the development team, and they should be able to explain what this is. Please be patient, as it will likely take a few days before we hear from them.

Best regards,

Simon

NOTE: I don't think it is a radio event, seeing as the spike on the nRF52840 test is too low to be the radio.