01 August 2016 User ReviewCheck your delivery options:
This circuit makes it easy to control your home appliances/devices through a remote. With this smart extension box we are able to switch on and off remotely any device such as fan, light, fridge, AC plugged into it. Here in this prototype we are showing an extension box which is able to control about 4 devices. But we can easily customize it to control more devices. RF remote control is used to control the extension box. As RF remote is used, range will be about 30 meters and line of sight communication is also not necessary.
Using HT12E encoder IC and HT12D decoder IC we can easily transmit and receive 12 bits of parallel data serially. HT12E simply converts 12 bit parallel data into serial output which can be transmitted through a RF transmitter. Of these 12 bits, 8bit represents the address bits and 4 bits represents the data. D0, D1, D2, D3 are the 4 data pins. Data pins at encoder section are connected to ON-OFF switches. Once the state of each device is set, Switch SW3 is provided to enable the transmission through RF transmitter. By varying the state of the switches, data corresponding to it will be encoded and transmitted.
Fig 1:SK_020_v1 Circuit Diagram
At the receiver side, RF receiver receives the data and send to decoder IC. LED indication is provided to ensure the data reception. Once the data is received at the HT -12D IC, it verifies the address. If the address on both the transmitter and receiver side is same, decoder decodes the data bits and made them available at D0 –D3 pin. Depending on the data at D0-D3 pin, transistor switches to on/off state which in turn drives the relay.
Fig 2:SK_020_v1 PCB Bottom Fig 3:SK_020_v1 PCB Top
RF Remote section: