Wireless Status Indicator

It is a wire-free communication project. We can reduce our time elapsed in the inspection of the status of any device without going near at that place. The project has two parts; transmitter & receiver.

Transmitter- Terminals P1 to P4 are used to connect the phase supply of the devices with the common neutral point. Whenever any device is switched-ON, a phase current runs in the circuit through P1/P2/P3/P4.  Optocouplor IC(MCT2E) receives this phase signal via 100KΩ resistors & then fed to the encoder IC(HT12E) where the final signal is modulated with an RF-module(TX-433) and transmitted via an antenna upto a long distance. Hence, upto four phase signal can be connected with the project simultaneously.


Receiver- The transmitted signal is demodulated here and the corresponding red LED will blink to show the status of devices. A blue led shows the signal reception & it must be blinked for required result. If the blue led is not blinked, then the receiver circuit is out of coverage of the transmitter & result may be incorrect.

Parts list:

  • IC HT12E
  • IC HT12D
  • IC MCT2E X 4
  • Transmitter Receiver Module TxRx433MHz or 315MHz
  • Resistor 100KΩ X 4
  • Resistor 330Ω
  • Resistor 100Ω X 2
  • LED X 5 (4 Red, 1 Blue)
  • Resistor 1MΩ
  • Resistor 47KΩ
  • DC5V Power supply
  • Battery 9V
  • Regulator IC7805
  • Switch, PCB etc.

Working principle can be understand by these block diagrams of transmitter and receiver section.

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