PPK2 LED stays red, no start option, no measurement options

[slavko]

I got PPK2, connected it to Windows 10 PC and it is recognized as "nRF Connect USB CDC COM5". LEDs turn on Grenn color but immediately fade out and becomes red and stays like that. nRFConnect's Power Profiler app, allows me to select device "PPK2", but after the selection nothing changes, I don't see the menu with measurement mode selection, start the measurement, etc. The log file shows "Validating firmware...| " Opening device ..." and stops thre.

[slavko]

Finally, I got it to work, using something that could be called the "Voodoo magic".

1. The magic only works if it is connected directly to my notebook. No USB hubs of any kind, powered from USB or its own power adapter, only directly to a notebook

2. Open the "Programmer" tool, select the PPK2 device and it will read the flash content

3. Close the Programmer

4. Open the Power Profiler

5. You get an Unknown device, select it

6. You will get a message "Device must be programmed", Select Yes and wait for it to be programmed

7  Once it is programmed, it will appear as a working PPK2 and you can use it....UNTIL

8. YOU CAN USE IT UNTIL YOU CLOSE THE POWER PROFILER APP.

9. Once closed, you need to go back to step 1 and repeat the VOODOO again. 

[Stian Røed Hafskjold]

Hi, this is strange. Seems like it only works when it's first put in bootloader mode. The programmer app will make the PPK enter bootloader mode, but for this to happen the PPK firmware must be running on the PPK. Which means that I believe that the issue is not with the PPK, but maybe the driver/software running on the computer. Are you able to test with another computer to verify this? Also can you capture the logs when you are able to successfully connect, after the "voodoo magic" trick? Please also try with another USB cable. Thanks.

Is it possible that the PPK device is captured by a virtual machine running on your computer, but not the "bootloader"-device?

[slavko]

Hi Stian, thank you for your suggestions. I have tried a couple of different USB cables and it makes no difference. However, when I tested on an older notebook (2012 model but still with Windows 10) it did work ok, even with a USB hub. The main difference is that, when connected to the older notebook, PPK2 LEDs stay green (fade in/out) and when I open the Power Profiler and select the device, it becomes red and turns back to green after I close the port.

With my newer notebook (HP Workstation 2019 model), the LED immediately goes to red color, when I connect the PPK2. Only after the re-programming, LEDs turn briefly to green and then to red, as it starts working ok. Here is the log file, when it works ok:

2021-09-28T11:06:08.439Z INFO Validating firmware for device with s/n D45D16655FD4
2021-09-28T11:06:17.628Z INFO Opening device with s/n D45D16655FD4
2021-09-28T11:06:18.095Z INFO Trigger length updated to 10 ms
2021-09-28T11:06:18.155Z INFO PPK started
2021-09-28T11:06:18.197Z INFO PPK opened

When it gets stuck, only the first two lines appear. Based on my experience, my best guess is some timing issue with your USB CDC stack, during the enumeration, but It could be that I am wrong. BTW. the same notebook (HP Workstation) works perfectly with nRF52 DK, nRF52849-Dongle, and any other device, either directly connected or via some USB hub, but again, I might be wrong, indirectly blaming the PPK2 firmware for this.

Also, there are no virtual machines running on my notebook and the driver reported for the PPK2 is Nordic driver, dated 11/05/2018

[Stian Røed Hafskjold]

Hi, sorry for the late response. I tried running this through the PPK team, but unfortunately we don't know exactly what is going on, except that there seems to be some driver issues. Do you have any virtual machine software running on the computer? We have seen issues when virtualbox is installed, even though no VMs are running.

[slavko]

Hi Stian and thank you for the update. The only things that resemble VM, that I got on my machine are Docker and WSL, but as far as I remember these are not even allowing me to access USB devices of the Windows 10 host. Anyway, all other USB devices operate normally, except for PPK2. For example, I don't have any issues with your nrf52DK, Segger's JLink, or other MCU's with CDC-based USB firmware. If I find some extra t will try to capture the USB traffic using Wireshark and send you the dump. If you have any other suggestions or if there are additional logging options that I could enable to get you more details, let me know.