Clapping music with Arduino: Difference between revisions

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* Starting point is the Example > Digital > toneMelody
* Starting point is the Example > Digital > toneMelody


'''Important''': ''tone'' is a unique command in that it is ''asynchronous'', meaning that when you call the function it starts playing the tone, but immediately returns control to your program. In Bash terms, it's like starting the program with the '&' character at the end -- the command runs "in the background". This is important to know, because you '''need'''to use the delay command to play consecutive tones, otherwise each call to tone undoes the previous ones.
'''Important''': ''tone'' is a unique command in that it is ''asynchronous'', meaning that when you call the function it starts playing the tone, but immediately returns control to your program. In Bash terms, it's like starting the program with the '&' character at the end -- the command runs "in the background". This is important to know, because you '''need to use the delay''' command to play consecutive tones, otherwise each call to tone undoes the previous ones.


'''So, the wrong way would be:'''
'''So, the wrong way would be:'''
Line 96: Line 96:


Now, using a [[C]] string with the [[Clapping music]] pattern.
Now, using a [[C]] string with the [[Clapping music]] pattern.
The clapping pattern can be implemented using calls to tone & delay:
<source lang="c">
int speakerPin = 13;
int thedelay = 100;
void setup() {}
void loop () {
  tone(speakerPin, 400, 10);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  delay(thedelay);
  delay(thedelay*10); // pause between repetitions
}
</source>
Now, we move from a hard coded pattern into using a C string (or char array), and the code becomes...
<source lang="c">
int speakerPin = 13;
int thedelay = 100;
char pat[] = "xxx xx x xx ";
int patlen = strlen(pat);
void setup() {}
void loop () {
  if (pat[0] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[1] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[2] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[3] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[4] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[5] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[6] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[7] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[8] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[9] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[10] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[11] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  delay(thedelay*10); // pause between repetitions
}
</source>
Notice how above the code is highly repetitive -- perfect for a loop!


<source lang="c">
<source lang="c">
int speakerPin = 8;
int speakerPin = 13;
int thedelay = 100;
int thedelay = 100;


// char keycode = 'x';
char pat[] = "xxx xx x xx ";
char pat[] = "x xx xxx xxxx xxxxx ";
int patlen = strlen(pat);
int patlen = strlen(pat);
   
   
Line 118: Line 194:
         i = i+1;
         i = i+1;
     }
     }
    delay(thedelay*10);
}
</source>
If you prefer, a for loop can be used instead (they are identical! the for statement is in fact shorthand for doing what the ''while'' loop does above.
<source lang="c">
int speakerPin = 13;
int thedelay = 100;


    // can be written in "shorthand" using the for statement...
char pat[] = "xxx xx x xx ";
     /*
int patlen = strlen(pat);
void setup()
{
}
void loop ()
{
     int i;
     for (i=0; i<12; i+=1) {
     for (i=0; i<12; i+=1) {
         if (pat[i] == 'x') tone(speakerPin, 400, 10);
         if (pat[i] == 'x') tone(speakerPin, 400, 10);
         delay(thedelay);
         delay(thedelay);
     }
     }
    */
     delay(thedelay*10);
     delay(thedelay*10);
}
}
</source>
</source>
Now, we remove the hard-coded length of the pattern (12) to use C's ''strlen'' function so that the pattern can be any length.


<source lang="c">
<source lang="c">
char pat[] = "xxx xx x xx ";
int speakerPin = 13;
int thedelay = 100;


void setup() {
char pat[]  = "x xx xxx xxxx xxxxx ";
    int patlen = strlen(pat);
int patlen = strlen(pat);
 
     for (int p=0; p<patlen; p++) {
void setup()
         if (pat[p] == 'x') {
{
            tone(8, 500, 10);
}
        }
         delay(100);
void loop ()
{
     int i = 0;
    while (i<patlen) {
         if (pat[i] == 'x') tone(speakerPin, 400, 10);
         delay(10);
        i = i+1;
     }
     }
    delay(thedelay*10);
}
}
void loop () {}
</source>
</source>


Here's a start at playing two parts (nearly simultaneously):


<source lang="c">
<source lang="c">
int speakerPin = 8;
int speakerPin = 13;
int thedelay = 100;
int thedelay = 100;


// char keycode = 'x';
char pat[]  = "x xx xxx xxxx xxxxx ";
char pat[]  = "x xx xxx xxxx xxxxx ";
int patlen = strlen(pat);
int patlen = strlen(pat);
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         i2 = i+5;
         i2 = i+5;
         if (i2 >= patlen) i2 = i2 - patlen;
         if (i2 >= patlen) i2 = i2 - patlen;
         //  maybe the % modulo operator could help!
         //  maybe the % modulo operator could help here!!!
          
          
         if (pat[i] == 'x') tone(speakerPin, 400, 10);
         if (pat[i] == 'x') tone(speakerPin, 400, 10);
Line 181: Line 281:
}
}
</source>
</source>
Tone only technically supports playing one tone at a time; how might it be possible to still produce something like the 2 parts necessary for clapping music.
   
   
[[User:Laura Macchini/prototyping/ArduinoClappingMusic | Laura's Clapping Music with Arduino]]
[[User:Laura Macchini/prototyping/ArduinoClappingMusic | Laura's Clapping Music with Arduino]]


[[User:Laurier Rochon/prototyping/clapping music button | Laurier's Clapping Music with Arduino and button]]
[[User:Laurier Rochon/prototyping/clapping music button | Laurier's Clapping Music with Arduino and button]]

Latest revision as of 18:37, 26 October 2010

This exercise relies on the following topics in C:

  • variable types (int, char)
  • character arrays (strings)
  • loops
  • nested loops

Hello world.c

Arduino is C!

#include <stdio.h>

main ()
{
  printf("hello world\n");
}

Blink music

void setup()   {                
  pinMode(8, OUTPUT);
  for (int i=0; i<1000; i++) {
    digitalWrite(8, HIGH);
    delay(1);
    digitalWrite(8, LOW);
    delay(1);
  }
}

void loop () {}


change the argument to the delay...

for my refined control, try delayMicroseconds

void setup()   {                
  int x;
  // initialize the digital pin as an output:
  pinMode(8, OUTPUT);
  for (int i=0; i<1000; i++) {
    digitalWrite(8, HIGH);
    delayMicroseconds(250);
    digitalWrite(8, LOW);
    delayMicroseconds(250);
  }
}

void loop () {}

tone

Important: tone is a unique command in that it is asynchronous, meaning that when you call the function it starts playing the tone, but immediately returns control to your program. In Bash terms, it's like starting the program with the '&' character at the end -- the command runs "in the background". This is important to know, because you need to use the delay command to play consecutive tones, otherwise each call to tone undoes the previous ones.

So, the wrong way would be:

int speakerPin = 13;
void setup() {
  tone(speakerPin, 500, 100);
  tone(speakerPin, 600, 100);
  tone(speakerPin, 700, 100);
  tone(speakerPin, 800, 100);
  tone(speakerPin, 900, 100);
}
void loop() {}

And the right way is instead:

int speakerPin = 13;
void setup() {
  tone(speakerPin, 500, 100);
  delay(100);
  tone(speakerPin, 600, 100);
  delay(100);
  tone(speakerPin, 700, 100);
  delay(100);
  tone(speakerPin, 800, 100);
  delay(100);
  tone(speakerPin, 900, 100);
  delay(100);  
}

void loop() {}

Clapping music.c

Now, using a C string with the Clapping music pattern.

The clapping pattern can be implemented using calls to tone & delay:

int speakerPin = 13;
int thedelay = 100;
 
void setup() {}

void loop () {
  tone(speakerPin, 400, 10);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  tone(speakerPin, 400, 10);
  delay(thedelay);
  delay(thedelay);

  delay(thedelay*10); // pause between repetitions
}

Now, we move from a hard coded pattern into using a C string (or char array), and the code becomes...

int speakerPin = 13;
int thedelay = 100;

char pat[] = "xxx xx x xx ";
int patlen = strlen(pat);
 
void setup() {}

void loop () {
  if (pat[0] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[1] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[2] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[3] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[4] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[5] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[6] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[7] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[8] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[9] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[10] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);
  if (pat[11] == 'x') tone(speakerPin, 400, 10);
  delay(thedelay);

  delay(thedelay*10); // pause between repetitions
}

Notice how above the code is highly repetitive -- perfect for a loop!

int speakerPin = 13;
int thedelay = 100;

char pat[] = "xxx xx x xx ";
int patlen = strlen(pat);
 
void setup()
{
}
 
void loop ()
{
    int i = 0;
    
    while (i<patlen) {
        if (pat[i] == 'x') tone(speakerPin, 400, 10);
        delay(thedelay);
        i = i+1;
    }
    delay(thedelay*10);
}

If you prefer, a for loop can be used instead (they are identical! the for statement is in fact shorthand for doing what the while loop does above.

int speakerPin = 13;
int thedelay = 100;

char pat[] = "xxx xx x xx ";
int patlen = strlen(pat);
 
void setup()
{
}
 
void loop ()
{
    int i;
    for (i=0; i<12; i+=1) {
        if (pat[i] == 'x') tone(speakerPin, 400, 10);
        delay(thedelay);
    }
    delay(thedelay*10);
}

Now, we remove the hard-coded length of the pattern (12) to use C's strlen function so that the pattern can be any length.

int speakerPin = 13;
int thedelay = 100;

char pat[]  = "x xx xxx xxxx xxxxx ";
int patlen = strlen(pat);
 
void setup()
{
}
 
void loop ()
{
    int i = 0;
    while (i<patlen) {
        if (pat[i] == 'x') tone(speakerPin, 400, 10);
        delay(10);
        i = i+1;
    }

    delay(thedelay*10);
}

Here's a start at playing two parts (nearly simultaneously):

int speakerPin = 13;
int thedelay = 100;

char pat[]  = "x xx xxx xxxx xxxxx ";
int patlen = strlen(pat);
 
void setup()
{
}
 
void loop ()
{
    int i = 0;
    int i2 = 0;
    while (i<patlen) {
        i2 = i+5;
        if (i2 >= patlen) i2 = i2 - patlen;
        //  maybe the % modulo operator could help here!!!
        
        if (pat[i] == 'x') tone(speakerPin, 400, 10);
        delay(10);
        if (pat[i2] == 'x') tone(speakerPin, 800, 10);
        delay(thedelay);

        i = i+1;
    }

    delay(thedelay*10);
}

Laura's Clapping Music with Arduino

Laurier's Clapping Music with Arduino and button