Weird current values with nRF52840 DK and Power Profile Kit

[zzxxcv]

Hello there,

I used both the oscilloscope and PPK to measure the current values. But both values are weird.

First, the PPK shows the current as large as 82mA. And I used the DK to do BLE connection. I suppose that the current should vary when the DK is doing different actions, like advertising connection, IDLE etc.

 

This is what I get. I previously get that current values when idle, but it still cannot have different current values when DK does different actions.

Now I just cannot get these more reasonable results.

The following pictures are how I prepared for current measurements. I follow instructions and think I did correctly.

1. cut soldering bridge of SB40

2. put DUT and Power select to DK

3. COM to DK

The values are weird.

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Then when I use the oscilloscope to measure the current.

The curve is oscillating and didn't show large differences when DK did different actions.

I also used multimeter to measure it directly, but current is stable all the way.

I need some help.

Thank you.

[Øyvind]

Hello, 

First of all, please verify that SB40 is cut, from the image you provide it looks like it's just heavily scratched. Also, what are the wires that go under the PPK? From the image, it looks like Power Select is set to Reg. 

Please verify that there are no short circuits.

Thank.

Kind regards,
Øyvind