Power profiler current measuring

[antoine98]

Hello, 

I'm trying to measure current on my nrf52dk board during a BLE communication. I'm doing that on a nrf52dk board. I connected the power profiler to the board as follows:

To measure the current in Ampere meter mode. However, when i turn on the board and start sampling the result that I can see on power profiler app is the following:

The measured current is really low. It looks like a noise more than a proper absorbed current. Am I doing something wrong?

Thanks in advance for the help

[Turbo J]

The picture looks like the SB next to the current connector still conducting, thus you cannot measure any current.

Your results are consistent with a 0A hypothesis - just a lot of measurement noise.

Put the target MCU in reset (pulling reset low) or in debug mode, this will consume at least a few hundred µA current (up to a few mA).

[Vidar Berg]

Looks to me from the picture that the solder bridge has not been cut.

Preparing a DK for current measurement

[antoine98]

I don't know if I exactly get the guide (I'm sorry to bother you, I'm a beginner).

So, if i want to test how much current does my application consume through ppk2 using amperemtere mode, I just need to cut SB9, right?

While SB9 has been cut would I'm be able to connect my board to USB and debug my application as I did before? 

What does it means that to restore normal DK function should i need to solder SB9? Which are the functions that i couldn't perform while this is cut?

Thanks again for the answers

[Vidar Berg]

The chip will not receive power after you've cut the connection. You can either re-solder the SB or place a jumper on the header. I recommend the latter as it makes it easy to change the board configuration between current measurement and normal operation.

[antoine98]

So, if I cut the SB9 solder and I connect the board to my PC while ppk2 is in ampere meter mode. Would I be able to execute my application in Segger and see how much this is consuming through power profiler app?

[Vidar Berg]

Yes, the chip will be powered when you short the connection through the ampere meter.

[antoine98]

Thanks for the help