There are many different types of FS20 units (by Conrad / ELV). Two new types of units came in recently. Here’s a power monitor which transmits power consumption via 868 MHz OOK in 5-minute intervals:

It’s recognized by the CUL receiver, showing readings such as these:

E0205010000000000001B
E0205020000000000001A
E0205030000000000001A
E0205040100010001001A

Hmm, looks like a cumulative power consumption counter… I plugged in a lamp before that last reading. Maybe there’s both cumulative and real-time power use in there. I’m sure the protocol has been analyzed… and indeed, here it is.

One drawback is that the addressing scheme is limited to at most four ES-1 sensors.

And here’s a little touch-sensitive control panel which can send up to 6 different commands and is made for mounting into the wall:

The panel can differentiate between short (on/off) taps and long (dimmer) taps, so one panel can actually emit up to 12 different signals. Again, this shows up in CUL:

F1000001204
F1000011217
F10000212F9
F1000031203

At € 36 and € 28, respectively, these units are not really affordable enough to sprinkle lots of them all over the house. Then again, maybe a few strategically placed power meters plus the total electricity meter pulses would be enough to figure out most power consumption patterns in the house…

The advantage of these of course is that they are plug-and-play. It ought to be easy to extend the current FS20 receiver code for the RFM12B so they recognize these extra bit patterns.