Power line communication based automation system using a handheld Wi-Fi device

An open source automation system for controlling electrical appliances using power line communication is presented here. Control messages are sent over Wi-Fi network from a Wi-Fi device to the microcontroller which then couples the messages to the power lines. Ubiquitous power lines are used as physical media to transmit data over 220V/50Hz signal to control appliances/equipment. The data from the microcontroller is coupled onto the power lines using a PLC (Power Line Communication) modem and DCSK (Differential Code Shift Keying) modulation technique is employed to transmit data. Each receiver unit consists of PLC modem plus microcontroller and can be connected anywhere in the power line network. The receivers have addresses assigned to them and only respond to the commands sent to them by the transmitter PLC modem. The receiver unit controls the flow of electricity to the socket. The entire system is devoid of a computer to save power and make it low cost. Use of open source hardware, Power Line Communication and micro-controller collectively reduce the cost of controlling appliances remotely.