I changed my os to the normal fairphone os and now my hid-pcb seems to work just perfect again…
Could it be that the drivers for Atmega32U4 were not installed or whatever?
Thanks for your response!!
@Cherry97, are you sure you mean USB OTG? Because this suggests you use the USB back connector. This evening I tried many things for about an hour to get the USB back connector (5 pogo-pins) working. My final conclusion was that it would probably be LineageOS. I’m still using 20171016 (didn’t know it had gone official), but this probably didn’t change. Is there anything I could do to diagnose within LineageOS why it doesn’t work? Or perhaps there is a driver missing? Logcat & dmesg don’t seem to do anything when plugging in something into the attached USB port.
I will update to the latest LineageOS when I have more time BTW, and re-test.
1 Like
Yeah you are right I used the back connector 
but isn’t that also otg, I mean FP is in host mode to handle my device ?
FP2 is in host mode usually only with a special USB-OTG-Adapter.
Any news about a fixed lineageOS? Or any idea his we can get these things fixed?
1 Like
… so perhaps just the new modem files are needed? Should be coming soon I guess.
1 Like
but also with the special update the phone is sometimes crashing (with the PCB-attached) …
I think somehow the FP2 can´t handle the serial communication sometimes… or a task is crashing which is related to the serial communication …
Maybe it´s about baud-rate?
What I have noticed:
-> FP is not rebooting until serial communication has started
(PCB has voltage -> draws current)
-> FP is not rebooting if USB-cable is attached (connected PC)
-> on any OS version the FP didn´t reboot until I rebooted it once or the battery was low an it
rebooted
They came out today … updated my phone with it … everything works normal but the back-pcb is still not recognized …
As it is working with the 18.3.1-Update - is there a way easily to find the differences between that image and lineage-os? To get a point where to look?
1 Like
it´s only working good with the special update…
So 18.2.0 is the image to look at !!
EDIT: i flashed Lineage again and like Drezil says the PCB is still not recognized …
but i looked into last_kmsg and there…
usb 1-1: New USB device found, idVendor=2341, idProduct=8037
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: Arduino Micro
usb 1-1: Manufacturer: Arduino LLC
…
EDIT: this maybe could be the fix: https://stackoverflow.com/questions/11183792/android-usb-host-and-hidden-devices
EDIT: is not added to handheld_core_hardware.xml
so does adding these lines in those files fix the problem?
what exactly should change? we should then also update the lineage-os-packages on github
1 Like
No nothing changed … 
We do have the file system/etc/permissions/android.hardware.usb.host.xml.
Chris
I didn’t even know that there’s a USB back connector on the FP2
Maybe this commit broke it…
2 Likes
Yeah that’s true but in handheld_core_hardware.xml it was missing… 
thought this would solve the problem…
Hmm that could be possible … How to fix?
I checked also last_kmsg and there the uC gets noticed as Arduino Micro, which is correct, so I think the cummincation would basicly work but something blocks it…
Herr you can see the last logs with logcat:
For me it does not even recognize anything in logcat…
Latest lineage ota
Can you compile a test-image for us so that we can see if this was indeed the problem? Or if it is something else?
here’s a boot.img that has the commit reverted
Flash with fastboot:
fastboot flash boot FP2_boot_back_usb.img
1 Like
will try that, thanks.
1 Like
that fixed it. The back-usb now recognizes the chip.
thanks!
1 Like
How can I use this ?