What is RF Module?

The wireless systems designer has two overriding constraints: it must operate over a particular distance and transfer a particular amount of data within a knowledge rate. The RF modules are very small in dimension and have a good operating voltage range i.e. 3V to 12V.

RF modules are 433 MHz RF transmitter and receiver modules. The transmitter draws no power when transmitting logic zero while fully suppressing the carrier frequency thus consume significantly low power in battery operation. When logic one is shipped carrier is fully on to about 4.5mA with a 3volts power supply. the info is shipped serially from the transmitter which is received by the tuned receiver. Transmitter and therefore the receiver is duly interfaced with 2 microcontrollers for data transfer.

How does it work?

two modules which are transmitter and receiver. The control of our data 1 and 0(we use the microcontroller during this project) and transmitter send these data in Seri way in radio waves. After ıt started broadcasting, the receiver collects these radio waves and it gives as 1 and 0 again.

Need of Encoder and Decoders:

The RF modules also can function without the necessity of Encoder and Decoder modules. Simply power on both the modules with the corresponding voltage mentioned above. Now, make the Din pin on transmitter high and you’ll find the Dout pin on the receiver also goes high. But, there’s an enormous drawback to the present method. you’ll have just one button on the sender side and one output on the receiver side. this may not help in building better projects, so we employ the encoder and decoder modules.

The HT12D and HT12E are 4-data bit encoder and decoder modules. this suggests that we will make (2^4 = 16) 16 different combinations of inputs and outputs. These are 18 pin IC’s which may operate between 3V to 12V input power supply. As said they need 4-data bit and 8-address bit, these 8 address bits need to be set same on both the encoder and decoder to form them work as a pair.

Circuit Diagram of RF Transmitter and Receiver:

Below pictures showing the RF Transmitter Circuit with Breadboard setup:

And below ones showing the RF Receiver Circuit with Breadboard setup:

Features of RF Module:

  • Low power consumption
  • Transmitter supply voltage 3v~6v
  • Transmitter output power 4v~12v
  • Receiver operating voltage 5v
  • Receiver frequency 433MHz
  • Receiver typical frequency 105Dbm
  • Receiver supply current 3.5mA
  • Transmitter frequency range 433.92MHz


  • Car alarm systems
  • Remote controls
  • Sensor reporting
  • Automation systems