OK, resolved.
The export of GPIO pin, for example

echo 4 > /sys/class/gpio/export
echo in > /sys/class/gpio/gpio4/direction

should be added to the domoticz.sh file placed in the /etc/init.d/ directory.
After this everything works fine. Initially, I thought that domoticz.sh placed in the ...

Hi,

I have used the same method for GPIO 21. I connected the PIR sensor to the 21st pin and it works correctly - it changes status in Domoticz.
One issue (mentioned in wiki), to make it work after the reboot you have to place appropriate records in the rc.local or domoticz.sh file.
This is ...