Phone application

Published January 2, 2021 © GPL3+

Play a melody by notes sent from a phone

Plays a text of notes sent from a phone to arduino through bluetooth

BeginnerProtip799

Play a melody by notes sent from a phone

Things used in this project

Hardware components

Arduino UNO

HC-05 Bluetooth Module

Speaker: 3W, 4 ohms

Rotary Potentiometer, 10 kohm

Toggle Switch, Toggle

Software apps and online services

MIT App Inventor 2

Story

This project was a funny idea while I tried to find out how the bluetooth module HC-05 works. As the first step I wanted to make a trial app for my phone to turn on and turn off a LED joined to the arduino board through the bluetooth.

When I sent a text from my phone to Arduino, its serial port received the letters (characters) of the text. First it was about to turn on and turn off the LED. But then an idea came and I said: "WOW", I can write a melody on my phone and send it to my Arduino to play it. And few minutes later I spent with my daugter some hours to create new and new songs that Arduino played.

So the melody can look like this:

2C..DE.E.D.D.C.C.

where "2" sets the octave for next tones to 1. We use the the range from 2 to 5.

and "." is not define, so it plays no tone. It pauses playing for the same long time as a note plays. We can use whatever not define symbol in the code instead of "."

Phone application

To create the app "Melody player" for the phone I used the MIT app inventor 2. Basic screen looks like this:

Picture 1

Where "Pair BlueTooth" is a ListPicker, then we need a TextBox "Melody" and 3 Buttons "PlayMelody", "SpeedUp" and "SpeedDown". Moreover we need to add a Clock component.

All the components are set in the "Blocks" part as following:

Blocks part of MIT app inventor 2

The code for Arduino is very simple too as you can see below.

Some notes to the curcuit:

- I use a 10k potentiometer to set the volume of the speaker, but you can use any you have, even a resistor (around 100 ohm)

- The switch for the bluetooth module is to turn it off when we load the code into Arduino. I use Arduino Nano and it cold not upload the code when the module was turn on

Code

Playing a melody sent from a phone

int note[110]; 
int micpin = 11;  //speaker
char BTData; //data from my phone
int oct = 1; //octave
int race = 200;  //speed of playing

void setup() {
    Serial.begin(9600);
    pinMode(micpin, OUTPUT);
    note['c'] = 247;    //ces = H
    note['C'] = 262;    //C
    note['d'] = 277;    //des = cis
    note['D'] = 294;    //D
    note['e'] = 311;    //es = dis
    note['E'] = 330;    //E
    note['f'] = 330;    //fes = E
    note['F'] = 349;    //F
    note['g'] = 370;    //ges = fis
    note['G'] = 392;    //G
    note['a'] = 415;    //as = gis
    note['A'] = 440;    //A
    note['h'] = 466;    //b = ais
    note['H'] = 494;    //H
}

void loop() {
  delay(5);
  
  if (Serial.available()){
      BTDataCases();
   }
}

void BTDataCases() {
      BTData = Serial.read();
      Serial.println(BTData);

      switch(BTData) {
        case '2':
          oct = 1;
          break;
        case '3':
          oct = 2;
          break;
        case '4':
          oct = 4;
          break;
        case '5':
          oct = 8;
          break;
        case '9':
          race += 20;
          break;          
        case '8':
          race -= 20;
          if (race < 20) race = 20;
          break;
        default:
          tone(micpin, note[BTData] * oct, race);
          delay(race + 100);
        }
     }

Credits

viliamk

14 projects • 5 followers

Play a melody by notes sent from a phone

Things used in this project

Hardware components

Software apps and online services

Story

Phone application

Schematics

Circuit diagram

Code

Playing a melody sent from a phone

Credits

viliamk

Comments

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Play a melody by notes sent from a phone

Play a melody by notes sent from a phone

Things used in this project

Hardware components

Software apps and online services

Story

Phone application

Schematics

Circuit diagram

Code

Playing a melody sent from a phone

Credits

viliamk

Comments

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