@lrtsenar The MySensors Libraries were designed around the nrf24l01 transceivers which have much more built in capability than a simple 433Mhz Tx/Rx pair. You can make a node which contains a nrf and 433 Rx/Tx and it can transfer messages between the MySensors architecture and common 433Mhz devices. If you are only interested in 433Mhz devices with Domoticz, see the RFLink project for more info. I believe it requires a mega to fit their libraries.