rf-bitbanger. Rf-bitbanger is a device driver for Raspberry Pi that allows writing of pulse sequences to the GPIO-pins. This makes it possible to connect for example a 9€ 433MHz transmitter directly to the RPi and control remote switches without any additional interface components (see picture above).
I have now made a first version of a rf-bitbanger-HomeItem which can transmit all protocols supported by NetHome via a rf-bitbanger port. This means that for only 9€ you can turn RPi into a complete home control system!