Mobile Incoming Call Indicator: Electronics Mini Project

Hello friends, are you searching for one good mini project for your submissions? If your answer is yes, then your search will end here. Today I am going to make a circuit that will indicate an incoming or outgoing call or message from your mobile phone. Yes, you can do such awesome mini project with some simple electrical components within no time. Let us start making our “Mobile incoming call indicator” mini project.

Components Used

  • IC 1 = NE555 (Timer IC)
  • Resistors
  • Capacitors
  • Transistor : Q1 = BC548
  • LED
  • 6V DC Battery
  • Diode: 1N5819


In this mini project, we are going to make a simple circuit that will detect a mobile phone. In this mini project, we have used a LED which will glow instantaneously when a mobile phone rings.

Whenever your mobile phone receive an incoming call, it will activate a transistor in the circuit. The coil L1 acts as an antenna which will sense the oscillations. These oscillations then are given to the base of transistor Q1 thus activating the transistor. As the output of transistor i.e. collector is connected to the IC 555 which get triggered and glows the LED connected to its output pin. Thus when LED glows we can conclude that there is an incoming call surrounding the circuit.

Circuit Diagram

Mobile Incoming Call Indicator Circuit Diagram 


  • In this mini project, we have used a 6 Volt DC power supply.
  • Build a circuit on a PCB (See: How to make PCB layout in Eagle software).
  • C1 & C3 are to be polyester capacitors.
  • The electrolytic capacitor C2 must be rated 10V.

IC 555 Pin configuration

IC 555 Pin configuration

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