I am analyzing the power consumption of a custom board with an nRF52833 BLE SOC and nRF21540 FEM for different BLE parameters. In one of my experiments I vary the amounts of advertising data and analyze the boards current draw using the PPK2. I am using thr nRF Connect SDK v2.6.4 to build my application.
During my experiments I noticed some weird effects that I cannot explain and hoped you could give me some insight into it. Screenshots of some of my measurements are shown at the end of this message.
For advertising data of size 25B to 31B i can see three similar peaks in my current measurement per advertising event. That is as I expected, because during one advertising event the advertisements are send on on channel 37, 38 and 39 in order.
For advertising data of size 17B to 24B i still see three peaks per advertising event, but the middle peak is way smaller than the first and last peak.
For advertising data of size 8B to 16B most of the times I see a behavior where the middle and last peak are way smaller than the first peak.
For adverting data data of a size below 8B most of the advertising events have three similar sized small peaks.
(The categorization is not strict. My measurements for 7B advertising data contained advertising events with one bigger peak, while my measurements with 8B advertising data had some advertising events consisting only of similar sized small peaks. This is similar for at my measurements for 16B and 17B advertising data).
For me the graphs for the data amounts 25B-31B and 0B-7B look more or less as I would expect. I would appreciate if you could explain what causes the different peak heights in the ranges 8B-16B and 17B-24B.
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Current for advertising with no advertising data (0B)
Current for advertising with 7B advertising data
Current for advertising with 8B advertising data
Current for advertising with 16B advertising data
Current for advertising with 17B advertising data
Current for advertising with 24B advertising data
Current for advertising with 25B advertising data
Current for advertising with 31B advertising data (maximum)
