i found Home Assistant on the internet and it is exactly what I need. There is only one thing, at the moment I use Homematic of Jens Maus on a RPi2 with a HM-MOD-RPI-PCB.
Now is my question, is there any possibility to run Homematic on Home Assistant without an second device (CCU)?
I found an alternative assistant called ioBroker they use a system called piVCCU. Is that also possible with the Home Assistant?
You could use Homegear as a middleware (BidCoS-Server) with your already existing HM-MOD-RPI-PCB. Integration into Homegear is easy and addressing Homegear as a remote Homematic-Server in Home Assistant is a matter of minutes.
Personally, I use a CC1101 communication module on a RPi3 and a HM-CFG-LAN gatway to communicate with my Homematic devices. Both are controlled by Homegear.
And - since Homematic is mostly used in Germany: Homegear is written by a German developer and the forum provides excellence support in English and German.