Sorry to butt in here. I had same problem to control GPIO on Raspberry Pi 4, but I have solved it fortunately. The following is just for your information. In my case, it is solved by downgrading Raspberry Pi OS. What I did was reinstall Raspberry Pi OS by using old Image (2020-02-05-raspbian-buster.zip) downloading from Raspberry Pi Site and didn't update module while I was installing the OS. My Raspberry Pi 4 is ... pi@raspberrypi:~ $ cat /proc/device-tree/model Raspberry Pi 4 Model B Rev 1.4 My...