Time scale way off
sheggy012 opened this issue · comments
Bug #141 is still present. See https://devzone.nordicsemi.com/f/nordic-q-a/95909/ppk2-and-power-profiler-desktop-time-scale-way-off/418883 . Makes it a pain to work with.
Hello @sheggy012, I can see from the original post on Devzone, that the problemed seemed to persist while connecting directly to the computer, but it seems to work when the PPK2 is connected to a hub. Have you been able to test with a USB hub, and in that case, does the issue still persist?
That is very unfortunate, and I will bring it up with the team after easter, to see if there's anything we can do about it.
Thanks for reporting.
Hi aadnekar,
yes exactly, as long as you put a USB hab in between, the time scale works. So there is at least a working workaround.
Thank you for bringing it up. Maybe it's possible to solve it for direct connection.
By the time I realized that the time scale was wrong, far too much time had passed. I have already started to exchange the oscillators on my PCB's because I suspected a fault there. 😄
I'm sorry to hear that @sheggy012, I will definetly investigate if we can fix this for direct connection. I will update this issue when I get more information.
I have the very same issue: the recorded time is only 32% of real time. I tried multiple USB ports (2.0 / 3.1), cables, OS (Windows 10 and Linux Pop!_OS 22.04) and a USB hub. The best combination still didn't go over 34%.
This is really messing with my calculations.
My motherboard is a "MSI - AMD AM4 mATX B350M gaming pro" (chipset = B350M).
I will see if there are BIOS updates available and report back.
Reporting back: I updated to the latest BIOS (2023-05-23-beta) and the problem persists.
But after tweaking many options on BIOS (most of which I don't understand) it improved from 32% to 48% of real time being captured. That also improved a bit the ringing that the PPK2 was displaying on both the current graph and the LA graph (the signal was fine as I probed it with an oscilloscope right at the PPK2 PCB).
But still, the LA was drawing the wrong duty cycle, and the ammeter losing samples and hallucinating about ringing.
Finally, I tried a live Linux USB drive ( Pop!_OS 22.04 ) on a borrowed INTEL laptop and connected PPK2 to it without disturbing the test circuit. All the problems disappeared.
As the two pictures show, apparently the only thing PPK2 seems to get right on AMD systems currently is the average current. Everything else is dependent on chipset's luck.
