Let's start with the beginning..
This is a gateway based system that uses the well known nRF24L01 wireless modules to communicate to small clients embedded in the power outlets or light switches.
The gateway is build around the Atmega 2560. the internet connectivity is done by the use of the ENC28J60 Ethernet module. A temperature sensor, a nRF24L01 module, a temporary LCD for simple debugging and SD card.
The power outlet clients are built around the much smaller Atmega 88 to insure cost effectiveness and the reduction of components (the quartz crystal). They also have the nRF module, a temperature sensor and in addition a bidirectional current sensor, a relay and a very simple and cheap power supply.
The light switches have everything the power outlet has, but instead of the relay, a thyristor is used to be able to dim the light bulb.
Now lets start with the problems :).
The clients should be connected to the gateway using a mesh network to insure proper communication even if the modules are far away, but this is what I'm still working on.