Thumbnail Piano

How to make a DIY Piano using IC555 timer


Bartolomeo Cristofori, around the year 1700, invented a string instrument which we call as Piano. In piano, we strike the strings, which are coated by wooden hammers that are coated with a softer material. We play it using a keyboard. In this project, we will see how we can make a simple piano using IC555 timer. Also, we will have a brief idea about how tone generators or synthesizers work by making this project.

Materials & Supplies,

Part List:

  1. IC555
  2. 50k POT
  3. 10k Pot( 3296 form)
  4. Resistors
  5. 100uF Capacitor
  6. IC Socket


  1. Soldering Iron
  2. Solder wire
  3. Helping Hands

Schematic & Gerber File,

Step 1: Understanding the working of Schematic

Using IC555, we will generate PWM signals, which we can convert it audio signals as well. If you need to know more about PWM, Check out the article on ‘How to generate PWM using IC555‘.

In schematic, we can see that it is a simple circuit in which we press a switch and the resistors regulate the voltage to IC555. This way, the circuit is complete each time we press one or more keys.
In this way by changing input voltage of IC555 we get Different tone.

Step 2: Circuit assembly & Soldering

When we understand the functioning of PWM and piano in general, we can construct a PCB for the same. Once it is ready, we can solder the components into their places.

After soldering, we only need to connect a 4 Ohm speaker to the circuit, connect it to 12V power supply.

Step 3: Changing output Note/Frequency

And when this project is complete, We can see when we vary the resistance, the frequency of the note played also changes.

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