What is your project about
Why did you decide to make it
How does it work
Circuit Schematic
Components & Connections
Musical Notes
Issues
Applications
Conclusion

Published November 19, 2022 © LGPL

DIY Piano | Make Piano with Touch based keys | Touch Sensor

This is an Arduino-based Piano. It has capacitive touch sensors instead of keys. No need to press it just touch it and play tunes on speaker

IntermediateFull instructions provided878

DIY Piano | Make Piano with Touch based keys | Touch Sensor

Things used in this project

Hardware components

Arduino UNO

Breadboard (generic)

Speaker: 0.25W, 8 ohms

General Purpose Transistor NPN

Resistor 10k ohm

Test Cable Assembly, Alligator Terminated Test Lead Set

Jumper wires (generic)

9V 1A Switching Wall Power Supply

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Multitool, Screwdriver

Scissor, Electrician

Wire Cutter / Stripper, 5.25 " Overall Length

Tape, Clear

Conductive Tape, Copper Foil

Story

Demonstration Video of the DIY Keyless piano with arduino

What is your project about?

This project is about making a piano from scratch. It does not have keys instead it has touch sensors. So, no need to press it just touch it. After touching it a tone is generated, and at last, we can combine different tones to form a melody.

Why did you decide to make it?

I have no experience with any music or musical instrument. So, I created one for myself. I would have interfaced different buttons with the Arduino UNO and speaker but that would be boring. To make it interesting, I added touch sensors instead of switches/buttons.

How does it work?

There is a capacitiveSensor library that turns two or more Arduino pins into a capacitive sensor, which can sense the electrical capacitance of the human body.

#include <CapacitiveSensor.h>

The sensor setup requires is a high-value resistor and a piece of aluminum foil on the end. The signal is sent from pin a of the board and received at another pin.

Aluminium Foil acting as touch sensor

So, the time constant, or the time taken for the signal to travel from one pin to another is calculated. By the formula R into C, or RC time constant. Whenever a person touches the aluminum foil, the capacitance changes. So does the time constant, this is how the touch of a human is detected.

Circuit Schematic

Circuit schematic for arduino piano with touch sensor based keys and speaker

This is the circuit schematic. The Arduino Uno board is connected to a piezoelectric buzzer via wires and a breadboard. There are touch sensing points. If a person touches it then, the microcontroller will detect it. There are 10-kilo ohm resistors connected between the microcontroller and the touch point. And the N-P-N transistor will act as a switch for the buzzer or speaker. Also, there is the 5 volts power supply. All these things are connected with the help of this breadboard.

Components & Connections

Arduino Uno

Arduino Uno R3

The Arduino Uno prototyping board is the main component and brain of the project.

Breadboard

Breadboard

Here we have the breadboard, to hold all the components together without the need to solder them.

Resistors

10 Kilo Ohm Resistor

Then we have 7, 10-kilo ohm resistors. we will connect them as per the schematic.

Transistor

NPN Transistor

This is an N-P-N transistor, it will be used for switching the speaker.

Speaker

1 / 2 • Speaker Front

And, Here is the speaker, it will be used to play the tones.

Alligator Clips

Alligator Clip

And alligator clips to make connections with foil strips.

Aluminium Foil Strip

Auluminium Foil Strips attach to cardboard

This is the main component of this project. It has a few aluminum strips glued to a cardboard strip. It will act as a touch sensor.

Musical Notes

Below are the frequencies that were assigned to different keys of the piano board.

Sa 240 Hz

Re 270 Hz

Ga 300 Hz

Ma 320 Hz

Pa 360 Hz

Dha 400 Hz

Ni 450 Hz

int freq[] = {240,270,300,320,360,400,450,480};

Issues

Whitenoise When we were not playing any tune, the speaker generated a lot of white noise.

The volume of sound was not constant, due to loose connections.

Playing this happy birthday tune required a lot of practice, as we don't have any background experience in music.

Applications

This circuit can be used as a touch sensor.

It can be attached to the knob or handle of the door to detect the touch of the burglar. Then trigger the alarm.

Also, it can be used to make a paper-thin piano, which will have the thickness of cardboard. It won't have any keys to be pressed. but touch sensors. Also, it can be foldable so as to carry it anywhere. A flexible computer keyboard can be made out of it.

Conclusion

Full demonstration Video

This was a very interesting project; we learned a lot while making it. We don't even know whether it is a piano or a harmonium. But we enjoyed it a lot playing tunes on it.

Code

Arduino Piano with tones, Interfacing with touch sensor and speaker

//Piano With Touch Sensor Sketch

#include <CapacitiveSensor.h>

const int sensitivity  = 1000; // default 30

//Sa 240 Hz, Re 270 Hz, Ga 300 Hz, Ma 320 Hz, Pa 360 Hz, Dha 400 Hz, and Ni 450 Hz, Sa 480 Hz
int sa = 240, re = 270, ga = 300, ma = 320, pa = 360, dha = 400, ni = 450;
int freq[] = {240,270,300,320,360,400,450,480};
int dly = 1000;

CapacitiveSensor   cs_4_5 = CapacitiveSensor(4,5);
CapacitiveSensor   cs_4_6 = CapacitiveSensor(4,6);
CapacitiveSensor   cs_4_7 = CapacitiveSensor(4,7);
CapacitiveSensor   cs_4_8 = CapacitiveSensor(4,8);        
CapacitiveSensor   cs_4_9 = CapacitiveSensor(4,9);        
CapacitiveSensor   cs_4_10 = CapacitiveSensor(4,10);        
CapacitiveSensor   cs_4_11 = CapacitiveSensor(4,11);

void setup()                    
{
   pinMode(A5, OUTPUT);
   cs_4_8.set_CS_AutocaL_Millis(0xFFFFFFFF);     // turn off autocalibrate on channel 1 - just as an example
   cs_4_9.set_CS_AutocaL_Millis(0xFFFFFFFF);     // turn off autocalibrate on channel 1 - just as an example
   cs_4_10.set_CS_AutocaL_Millis(0xFFFFFFFF);     // turn off autocalibrate on channel 1 - just as an example
//   Serial.begin(9600);
}

void human(){
  
  long total1 =  cs_4_5.capacitiveSensor(sensitivity);
  long total2 =  cs_4_6.capacitiveSensor(sensitivity);
  long total3 =  cs_4_7.capacitiveSensor(sensitivity);
  long total4 =  cs_4_8.capacitiveSensor(sensitivity);
  long total5 =  cs_4_9.capacitiveSensor(sensitivity);
  long total6 =  cs_4_10.capacitiveSensor(sensitivity);
  long total7 =  cs_4_11.capacitiveSensor(sensitivity);
  
  int thresh = 25;
  
  if(total1>thresh){
    tone(A5,freq[0]);
  }else if(total2>thresh){
    tone(A5,freq[1]);
  }else if(total3>thresh){
    tone(A5,freq[2]);
  }else if(total4>thresh){
    tone(A5,freq[3]);
  }else if(total5>thresh){
    tone(A5,freq[4]);
  }else if(total6>thresh){
    tone(A5,freq[5]);
  }else if(total7>thresh){
    tone(A5,freq[6]);
  }else{
    noTone(A5);
  }
}

void robotic_hbd(){
  int freq[] = {
    sa,sa,re,sa,ma,ga,
    sa,sa,re,sa,pa,ma,
    sa,sa,dha,pa,ma,ga,re,
    ni,ni,dha,ma,pa,ma,
    sa,re,sa,ma,ga,
    sa,re,sa,pa,ma,
    sa,dha,ma,ga,re,re,
    ni,ni,dha,ma,pa,ma
  };
  int i=0,l=sizeof(freq)/sizeof(int);
  
  for(i=0;i<l;i++){
    tone(A5,freq[i]);
    delay(150);
    }
}

void loop(){
  human();
//  robotic_hbd();
}

DIY Piano | Make Piano with Touch based keys | Touch Sensor

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

What is your project about?

Why did you decide to make it?

How does it work?

Circuit Schematic

Components & Connections

Musical Notes

Issues

Applications

Conclusion

Schematics

Arduino Interfacing with touch sensor and speaker

Code

Arduino Piano with tones, Interfacing with touch sensor and speaker

Credits

Robotics EveryDay

Comments

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DIY Piano | Make Piano with Touch based keys | Touch Sensor

DIY Piano | Make Piano with Touch based keys | Touch Sensor

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

What is your project about?

Why did you decide to make it?

How does it work?

Circuit Schematic

Components & Connections

Musical Notes

Issues

Applications

Conclusion

Schematics

Arduino Interfacing with touch sensor and speaker

Code

Arduino Piano with tones, Interfacing with touch sensor and speaker

Credits

Robotics EveryDay

Comments

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