Home Automation with Raspberry and FHEM software, building my own RF interface

After trying a couple of home automation solutions like Homematic, Medialog and some other propriary solutions, I decided to build some hardware interface with the Raspberry based Open-Source FHEM solution. The software is easly installable and there is a lot of documentation about it. The constrains is that the RF adapters are not cheap. As I had some Hope RFM12b and RFM23 modules, I decided to make my own interface. The RFM12B module is very limited and the the RFM23 module had no documentation about using it in OOK mode, meaning using it to send commands to plugs.

Main goal:

1. Interface a Ventus W155 weather station, mainly the Temperature sensors and the Wind and Rain Sensor.

2. Low-Cost 220V ELRO plugs

Both products using 433mhz OOK interface. OOK means you switch on and off the RF carrier.

The main issue I had with a Mediola controler was that the distance to control the plugs was very limited wiht Gateway 4.0, so one test would be to check if the RFM23 module would be able to send more powerfull waves accross the flat. Basically the transmission at 433mhz is free, but limited to 1% bandwith occupation and transmitting 10mW max. power.

 

The documentation that will follow will include the hardware setup (Arduino/RFM23 connection), the modified FHEMduino modules and the modified FHEM Perl modules.

 

More to come soon...  1.8.2015