Touch screen stopped responding
So after just getting a trial version up and running, touch screen working during the entire setup, after adding printers and configuring everything in my browser, the touch screen no longer responds. It's on, I can see it, but can't use it. I have a rpi 4b attached to a 7" touchscreen. Is there a step I've missed? It's not making sense to me because it was working. All in about a one hour span. Sorry if my description is too vague, but I don't know how else to explain it.
Comments
It can also be a defect. I had already one original touch screen where suddenly the upper half did not work any more. Especially if it worked and you did not change touch calibration that is a possible reason.
With mouse not hidden you can also connect a real mouse to control the interface. But touch is of course better since we optimized it for this.
Does this require some extra module being loaded? Or does it work out of the box?
lsusb
on ssh connection will show list of connected usb devices. Find out which is your display then you see if it is still recogniced. You can also check /var/log/syslog - there linux logs all important messages. So if it does change touch handling I'm quite sure you will find a message about that there.
The gui has a bolt icon where you see if you had undervoltage. During undervoltage linux disconnects usb devices so that can in deed be the case. You could close the 5v line in printer usb cable so printer will not draw current from the pi, see here:
https://www.repetier-server.com/knowledgebase/undervoltage-and-throtteling-of-pi/
tail -f /var/log/syslog
and plug in the printer. Then I would expect the important part in the log that appears then. Hit Ctrl+C to stop logging.