@mwittig i must say thank you to you for spending so much time in my problem!
so, i have news but first, no, i don´t use pimatic as root, should i? what advantage have i in case of running it as root?
i test it as user pi with ls -lHA /dev/ttyAMA0 and also as root but always the same error.
Then i also digged deeper and found (for me) a solution in the web.
On a other forum (i have forget which…) there was a discussion with the same problem of the /dev/ttyAMA0 and there was the Solution approach to change the:
enable_uart=0 into enable_uart=1
at boot/config.txt
For me now it works!
pi@raspberrypi:/ $ ls -lHA /dev/ttyAMA0
crw-rw---- 1 root dialout 204, 64 Jan 18 20:29 /dev/ttyAMA0
pi@raspberrypi:/ $
Can you test this @mwittig?
Thank you!
P.S. now i have a little other problem. The suply for the MCP are 3,3V from the Pi. I will use them as Input to check the lights of my house (Whether they are on or off). So i return 3.3V on the pins, over the relays. At a device i take i J5 Presence Sensor but i don´t get a high or low signal only flicker. At low i have 0,26V at the Pins and high 3,36V. But nothing change at the device… must i work with pull-down?
Thanks