[Tutorial] Making PIANO KEYBOARD with LM555 IC

Hi everyone, today I will guide you how to make a powerful piano keyboard with LM555 IC. OK let's go!

Piano keyboard description
Here we will show how to build a piano keyboard which generate simple electronic keyboard musical notes DO, RE, MI, FA, SOL, LA, SI, DO1 and RE1, as shown in the following diagram (keyboard piano).
Piano Keyboard with IC LM 555
Piano Keyboard with IC LM555

Piano keyboard operation circuit
This circuit has a piano keyboard wave generator essentially comprises a 555 which operates as an astable multivibrator circuit. This type of operation is characterized by an output square wave of width defined by the designer. The outgoing wave frequency can be controlled by the resistor is connected between pins 7-8 and 2-7 in addition to the capacitor connected to pin 2 grounded. The resulting frequency can be calculated under the following equation.
Where R eq is the result according to the push button is pressed on the keyboard piano.

Therefore we can in our piano keyboard similar sound of an electronic organ basic shape regulating the output frequency to musical notes

RE1 493Hz R2-R3
DO1 440Hz R2-R4
392Hz IF R2-R5
THE 349Hz R2-R6
SOL 329Hz R2-R7
FA 293Hz R2-R8
MI 261Hz R2-R9
RE 246Hz R2-R10
DO 200Hz R2-R11

Materials piano keyboard.

  • 1 Resistance 10K Ohm 1/4 W
  • 1 Resistance 8.2K Ohm 1/4 W
  • 1 Resistance 5.6K Ohm 1/4 W
  • 2 6.8K Ohm resistors 1/4 W.
  • 2 4.7K Ohm Resistors 1/4 W
  • 2 3.3K Ohm resistors 1/4 W.
  • 2 2.2K ohm 1/4 W resistors
  • Ceramic Capacitor 10nF
  • 1 Ceramic Capacitor 10nF
  • 1 Ceramic Capacitor 100nf.
  • 1 47uf 25v Electrolytic Capacitor
  • 1 LM555 .
  • Speaker 8 Ohm 0.25W to 1W.
  • 9 Push.

Want to know more about the 555? Comment below.


  1. what are the values of the resistors please, Many thanks Tom


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