Friday, 23 December 2011

remote controller appliances

We make this project to control the appliances installed in our home or industry via remote. we use a RF Transmitter / Reciever for exchanging the bits to turn on or off the devices in a particular range (typically10-100 meters). The figure of remote controlled home automation shows how the devices are turn off and on. Basically a receiver circuit is installed in our home this circuit is connected to the devices by the relay(electromechanical switch).
Remote controlled home automation 
The major components to implement a remote  are:-
  • RF Transmitter module
  • HT12E(4bit encoder)
  • power supply
  • PUSH button circuit
The major components use to make receiver box are:-

  • RF Receiver module
  • HT12D(4bit decoder)
  • power supply
  • controller circuit
  • relay circuit

REMOTE: The remote for our system is consist of several component as listed above the RF Transmitter module is connected to the encoder ic output. The encoder(HT12E) encode a four bit data into a single bit that is Dout which is get into the RF transmitter module and the transmitter module transmit it into the particular area.

**RF Transmitter Module: The transmitter module is working  on the frequency of 433MHz and is easily available in the market at the cost of 250rs .
  • The vcc pin is connected to the +terminal in the circuit.
  • The data pin is connected to the HT12E(pin no-17) that is transmitted or we can say that encoded data.
  • The next pin is shown in figure is GND that is connected to the ground terminal.
  • now the last pin ANT this is connected to a small wire as an antenna.
HT12E encoder
 **HT12E Encoder IC: The HT12E is an 4bit encoder which encode the input data applied on it .The pin description of the HT12E is shown in the figure .
  • pin (1 to 8) A0-A7 known as address bits so we do not need to consider them.
  • pin no (9 and 18) are use to bias the IC  as pin-18 as VCC and pin-9 as GND.
  • pin - 17 is connected to the rf transmitter module Din.
  • pin-16 and pin-15 are connected by an Osc resistor known as Roscc(1.1 Mohm)
  • pin-14 is connected to ground to enable the transmitt.
  • pin-13 to pin-10 are known as AD0 to AD3 those having the 4bit data which is required to transmitt.
**power supply: The power supply to this circuit is given by a 9volt battery for more detail click here

actual remote

RECEIVER BOX:The receiver box consist of the circuit of RF Receiver module , the decoder IC HT12D circuit, decision ciruit (Microcontroller 8051 circuit ) , relay and relay driver circuit (ULN 2003 IC circuit), 

About the Author


Author & Editor

Hobbyst Researcher and working in electronics domain, M.Tech in VLSI Design and Embedded Systems.


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