Issues with the new PPK2

[navman]

Hi nRF

I just bought the new PPK2 tool which I think is awesome. However I think there are some issues with it.

Issue 1:

First of all thy X axis scaling is wrong by a factor of 6, that is the time measurements performed/showed in the PPK2 Power Profiler tool reports timing to be 6 times shorter than real life. See attached pictures. The "Power profiler snaphot" file is a snapshot of the current consumption of 869 Mhz transmitter in active transmitting state. As can be seen the selected area is reported to be ~60 ms. However taking the measurement with an oscilloscope (voltage drop over a 5 ohm series resistor) it is reported to be ~370 ms (time between the cursors in the "oscilloscope snaphot" file). Are these observations correct? I also noticed that when the X scale is set to a span of 3 sec I would expect a current change to take 3 sec to travel from right to left when live view is turned on. However it takes 18 sec. Am I missing something here?

Issue 2:

Again looking at the Power profiler snaphot" file, in the selected area there are a lot of measurement points reporting almost 0 uA current drawn by the DUT, but in the "oscilloscope snapshot" file, it doesn't reveal that (which is correct). Is this due to auto-scaling of the measurement circuitry within the PKK2 tool? At other points the PKK2 tool reports up to 27 mA but the DUT only consumes ~5 mA in theses states, I guess this is the same issue just sort of reversed (or could it by RF from my 10mW transmitter entering the sensitive measurement circuitry in the PKK2?)

Can you confirm there are issues with the tool or do I have a faulty unit?

0675.Power Profile Snapshot.pdf

7522.Oscilloscope Snapshot.pdf

br

Kim

[Øyvind]

Hi Kim, 

We are aware some issues with the new PPK2. I have reported back to our R&D team, and will get back to you next week.

Kind regards,
Øyvind

[Øyvind]

Kim, 

Can you please provide more details around your setup? What window size do you have during sampling? Have you zoomed in on the result after sampling? what do you see when sampling in different window size in the application? Can you please do several test with different configurations? 

How is your PPK2 connected to the computer, are you using a USB HUB?

Thanks

-Øyvind

[navman]

The previous snapshots was using a 1sec sampling window setup and then zoomed in to app 0.6sec. I have taken a new snapshot of the same application (tx transmitting in app. 360 ms - marked area in the snapshot) without zooming in/out. Also attached is the same snapshot but this time zoomed into a span of app. 86ms.

Also attached a sample on the same application using 100ms sample window with no zoom applied.

The PPK2 is attached to a USB 3.1 Gen. 1 port directly to my PC using a 1m long USB cable (no hub). But since you asked about the USB port used, I tried to move the PPK2 to another USB port (USB 3.1 Gen. 2) on my PC and that changed the picture quite a lot. See attached file "Snapshot 1sec windows no zoom new USB port". The timing changed completely and so did the waveform. I also tried another USB cable but that didn't make any difference. I then moved the PPK2 to my laptop also using a USB 3 port and once again a completely new waveform and timing. Timing changed to be slower than real time and most of the "sampling noise" disappeared. See attached file "Snapshot 3 sec windows no zoom laptop". I have no clue on what is going on.

Snapshot 1sec window no zoom.pdf

Snapshot 1sec window with zoom.pdf

Snapshot 100ms window no zoom.pdf

Snapshot 1sec window no zoom new USB port.pdf

Snapshot 3sec window no zoom laptop.pdf

br

Kim

[PVitek]

Hi Øyvind,

I have the same problem. I'm using PPK1 kit and it works very well. Now I bought the PPK2 kit and the measurement is not applicable. There was a lot of noise and sample inaccuracy in the measured data.

I measure on my golden device, where I know current profile. The measurement was created on the PPK1 and PPK2 kit.

I use a desktop computer without a USB hub. nRF Connect v3.6.1, Power profiler v3.0.3

Start up device sequency:
PPK1_StartAppCurrent
PPK2_StartAppCurrent

Transmitting on the Sigfox:
PPK1_TxSigfoxCurrent
PPK2_TxSigfoxCurrent

Sleep mode with 100 ms wake-up periode:
PPK1_SleepModeCurrent
PPK2_SleepModeCurrent

Flashing LED in sleep mode:
PPK1_FlashLedCurrent
PPK2_FlashLedCurrent

Can you confirm that there is a problem with the tool or that I have a defective unit?

Thanks,

Petr

[Øyvind]

Hello PVitek,

Can you please provide a description of your measurement setup? This way we can try to reproduce the issue here. 

Thank you. 

Kind regard,
Øyvind

[PVitek]

Hi Øyvind,

I am using a custom IOT device where the MCU is STM32G030xx and the Sigfox SFM10R1 module.

Measure configuration:

Measure_setup

Destop PC -> 1 m USB cable -> PPK1/PPK2 - source meter 3.3V -> 15 cm cable -> device.

Today I measure other tests in an ampere meter with a laboratory power supply HAMEG HM7042-5 and a battery. The result is better. I think it's a hardware problem in insufficient power filtering.

HAMEG have configuration 3.3V and battery 3.6V.

Start up device sequency:
PPK2_StartUpCurrent_HAMEG
PPK2_StartUpCurrent_3V6_Battery

Transmitting on the Sigfox:
PPK2_TxSigfoxCurrent_HAMEG
PPK2_TxSigfoxCurrent_3V6_Battery

Sleep mode with 100 ms wake-up periode:
PPK2_SleepModeCurrent_HAMEG
PPK2_SleepModeCurrent_3V6_Battery

Flashing LED in sleep mode:
PPK2_FlashLedCurrent_HAMEG
PPK2_FlashLedCurrent_3V6_Battery

I can try create some code for STM32 nucleo dev kit for reproduction.

Best regard,

Petr