Pitch Follower with Analog in

INPUT: Photocell
OUTPUT: Buzzer

DESCRIPTION: Pitch is changed by lighting, has On/Off switch.

[code lang=”arduino” light=”true”] const int buttonPin = 2; // the number of the pushbutton pin
int buttonState = 0; // variable for reading the pushbutton status

const int numReadings = 10; //average 10 values

int readings[numReadings]; // the readings from the analog input
int index = 0; // the index of the current reading
int total = 0; // the running total
int average = 0; // the average

int inputPin = A6;

void setup() {
// initialize serial communications (for debugging only):
Serial.begin(9600);
pinMode(buttonPin, INPUT_PULLUP);
// initialize all the readings to 0:
for (int thisReading = 0; thisReading < numReadings; thisReading++)
readings[thisReading] = 0;

}

void loop() {
//read the button and store it’s state in new variable
buttonState = digitalRead(buttonPin);

// subtract the last reading:
total= total – readings[index];
// read from the sensor:
readings[index] = analogRead(inputPin);
// add the reading to the total:
total= total + readings[index];
// advance to the next position in the array:
index = index + 1;

// if we’re at the end of the array…
if (index >= numReadings)
// …wrap around to the beginning:
index = 0;

// calculate the average:
average = total / numReadings;
// send it to the computer as ASCII digits
Serial.println(average);

// map the pitch to the range of the analog input.
// change the minimum and maximum input numbers below
// depending on the range your sensor’s giving:
int thisPitch = map(average, 30, 0, 100, 1000);

// if button in pressed do this…
if (buttonState == LOW){

// play the pitch:
tone(7, thisPitch, 10);

delay(1); // delay in between reads for stability
}

}
[/code]