Introduction: Home Automation Using RF Modules

What is Home Automation? Well, home automation is the use of one or more computers to control

basic home functions and features automatically and sometimes remotely. An automated home is sometimes called a smart home.

What is RF? Well, Radio frequency (RF) is any of the electromagnetic wave frequencies that lie in the range extending from around 3 kHz to 300 GHz, which include those frequencies used for communications or radar signals. RF usually refers to electrical rather than mechanical oscillations.

Step 1: Home Automtion


over Radio Frequency has many advantages as it doesn’t require a line of sight connection between the transmitter and receiver as in case of Infrared communication.

The range of RF communication is very high when compared to IR communication. In this project, a wireless transmitter and receiver system using RF modules (RF Transmitter and RF Receiver) is implemented.

An RF Transmitter and Receiver pair is used for wireless communication. The wireless data transmission is done using 433 MHz Radio Frequency signals that are modulated using Amplitude Shift Keying (ASK) Modulation technique.

In order to implement the wireless transmitter and receiver, we use an encoder IC HT12E and a decoder IC HT12D.

Components Used:

1) Integrated

(i) HT12E- encoder IC-2

(ii) HT12D- decoder IC-2

(iii) CD4013- Flip Flop-4

2) Modules:

(i) Relay module- 6 Channel- 1

(ii) RF transmitter-1

(iii) RF receiver-1

3) Miscellaneous:

• Generalized PCB

•IC bases- 18 pin- 4, 14 pin- 4

•Connecting wires

•LED’s- 9

•Batteries- 4xAAA(Transmitter)

•Push buttons- 8

•Power cable (3 pin)-1

•Junction box-1


•Transformer-1(step down)

•Bridge rectifier- 1

•Capacitor- 1x4700uf/63v

•Resistors- 1K/0.25W-9


•In order to show the working of wireless communication
between transmitter and receiver, 8 LEDs at receiver side are controlled by 8 buttons at transmitter section.

•The HT12E encoder IC converts the 4-bit parallel data from the 4 data pins that are connected to buttons into serial data. This serial data is sent to RF transmitter. The RF transmitter transmits this serial data using radio signals.

•At the receiver side, the RF receiver receives the serial data. This serial data is sent to HT12D decoder IC which converts into 4 bit parallel data.

•The 4 data pins of decoder are connected to LEDs. According to the buttons pushed, the LEDs can be turned ON or OFF.


•As RF Modules doesn’t
require line of sight communication, the transmitter and receiver can be isolated over a distance and data can be transmitted successfully.

•The wireless transmitter and receiver can be used in car door and garage door controllers.

•They can also be used in home automation systems.