Connect openhab on a raspberry to and arduino running the serial gateway

[LastSamurai]

Hi, I have an arduino uno running the serial gateway sketch and another one with a DHT-11 sensor running that sensor sketch from the demo. Thats working fine. On my computer in the serial monitor from the arduino IDE I see the messages at the gateway from the other node.
Now I installed openhab 1.7.1 on an raspberry pi and connected the "serial uno" via usb to that pi. Using minicom I can see the same messages there as before. I used this tutorial to create demo sensors for openhab. The only parts I changed are:

• The childnode is 105 for me
• and the serial port for the arduino is /dev/ttyACM0 (thats what dmesg said)

The problem is that I don't see any updates in the openhab log. No reaction at all to the arduino. I can open the webpage with the demo sitemap but the values there are just -.

Any idea where the error is or how I can get it to work?

[LastSamurai]

Ok I found the error. I may or may not have forgotten to add the serial addon It is strange though that you get no kind of error message without that...