Linknx

Linknx is only one component of a bigger project. The goal is to get the maximum comfort and flexibility from my KNX domotic system while keeping the smallest possible resource consumtion (in other words, I don't wanted to have a dedicated PC running 24/7 for this). To achieve this goal, I use a Linksys WRT54GS wifi router running OpenWRT. The physical access to the KNX bus is ensured by the EIBD daemon, connected to the bus using a BCU2 bus coupling unit and a home made-interface using FT1.2 protocol.

With EIBD running and connected, we can send and receive telegrams on the bus, but a major component is still missing. We need something to keep the state of all the group objects, so that a visualization or automation tool can get this state instantaneously without having to request it over the KNX bus.

That's the job of linknx:

• Keep state of all configured group objects
• Allow other components of the system to read/modify this state
• Allow user to configure rules, specifying actions to execute when a condition is met

Information about LinKNX configuration, interaction with other applications and EIBD interface to the KNX bus are covered in details in the LinKNX Wiki

With the XML based interface provided by linknx, a visualization web component can be realized very easily. As a proof of concept, I made a small php example displaying light and heating status of a house.

For advanced configuration, my plan is to develop a java GUI app or applet interacting with linknx using the same XML protocol.

The most up-to-date information about XML based interface to linknx can be found in the wiki page Interacting with Linknx