09d. Tone Synthesis

Today we are not building a Theremin but we are going to make a lot of annoying noise with our piezo speaker.

//Note-to-Frequency mapping
#define NOTE_C4  262
#define NOTE_CS4 277
#define NOTE_D4  294
#define NOTE_DS4 311
#define NOTE_E4  330
#define NOTE_F4  349
#define NOTE_FS4 370
#define NOTE_G4  392
#define NOTE_GS4 415
#define NOTE_A4  440
#define NOTE_AS4 466
#define NOTE_B4  494
#define NOTE_C5  523
#define NOTE_CS5 554
#define NOTE_D5  587
#define NOTE_DS5 622
#define NOTE_E5  659
#define NOTE_F5  698
#define NOTE_FS5 740
#define NOTE_G5  784
#define NOTE_GS5 831
#define NOTE_A5  880
#define NOTE_AS5 932
#define NOTE_B5  988
#define NOTE_C6  1047
#define NOTE_CS6 1109
#define NOTE_D6  1175
#define NOTE_DS6 1245
#define NOTE_E6  1319
#define NOTE_F6  1397
#define NOTE_FS6 1480
#define NOTE_G6  1568
#define NOTE_GS6 1661
#define NOTE_A6  1760
#define NOTE_AS6 1865
#define NOTE_B6  1976
#define NOTE_C7  2093
#define NOTE_CS7 2217
#define NOTE_D7  2349
#define NOTE_DS7 2489
#define NOTE_E7  2637
#define NOTE_F7  2794
#define NOTE_FS7 2960
#define NOTE_G7  3136
#define NOTE_GS7 3322
#define NOTE_A7  3520
#define NOTE_AS7 3729
#define NOTE_B7  3951
 
int speakerPin = 9;
int frequency = 261;
int duration = 1000;
 
void setup()
{
  pinMode(speakerPin, OUTPUT);
}
 
void loop()
{
    tone(speakerPin, frequency);
    delay(duration);
    noTone(speakerPin);
    delay(duration);
}

With variable frequency:

int speakerPin = 9;
int frequency = 261;
int duration = 10;
 
void setup()
{
  pinMode(speakerPin, OUTPUT);
}
 
void loop()
{
  for(int i = 100; i<1000; i++)
    {
    tone(speakerPin, i);
    delay(duration);
    noTone(speakerPin);
    delay(duration);
    }
}

Now let’s make our first electronic instrument:

int speakerPin = 9;
int sensorPin = A0;
int frequency = 261;
int duration = 10;
 
void setup()
{
  pinMode(speakerPin, OUTPUT);
  pinMode(sensorPin, INPUT);
  Serial.begin(9600);
}
 
void loop()
{
    //Serial.println(sensorValue, DEC); 
    int sensorValue = analogRead(sensorPin);    
    int value = map(sensorValue, 0, 1024, 100, 5000);
 
    tone(speakerPin, value);
    delay(duration);
    noTone(speakerPin);
    delay(duration);
 
}

Ok that’s getting very annoying let’s use a pushbutton to activate the sound.

int buttonPin = 12;
int speakerPin = 9;
int sensorPin = A0;
int frequency = 261;
int duration = 10;
 
void setup()
{
  pinMode(speakerPin, OUTPUT);
  pinMode(buttonPin, INPUT);
  pinMode(sensorPin, INPUT);
  Serial.begin(9600);
}
 
void loop()
{
    int buttonState = digitalRead(buttonPin);
    Serial.println(buttonState, DEC); 
 
    if(buttonState)
    {
    int sensorValue = analogRead(sensorPin);    
    int value = map(sensorValue, 0, 1024, 100, 5000);
 
    tone(speakerPin, value);
    delay(duration);
    noTone(speakerPin);
    delay(duration);
    }
 
}

Now try the soft pot. And try the flex sensor, pressure sensor and the light sensor (you’ll need a pull down 10K resistor for these, see CIRC-13 on the booklet).