/*

  Microphone Light On/Off Example

  

  This is an example that show how a light can be turned on and off by a high sound.

  The light stays in its state unil a new high sound arrives.

  

  Circuit

    - Electret microphone

    - 220 ohm resistor

    - LED

  

  Created by Inge Edward Halsaunet, 2015

  Released into the public domain

*/







const int micIn = 2;    // Digital pin the microphone is connected to

const int ledOut = 3;   // Digital pin the led is connected to




int previousSensorReading = 0;  // Remember the previous reading of our microphone

int state = LOW;                // Current led state (HIGH or LOW)




void setup() {

  // Start serial communication with console

  Serial.begin(9600);

  // Initialize inputs and outputs

  pinMode(micIn, INPUT);

  pinMode(ledOut, OUTPUT);

}




void loop() {

  // Read the current microphone level

  int sensorRead = digitalRead(micIn);

  // See if reading has changed since last time

  if (previousSensorReading != sensorRead) {

    // Remember to update previous reading

    previousSensorReading = sensorRead;

    Serial.print("Changed, now: ");

    

    // When senosor is in high state, only notify user.

    if (sensorRead == HIGH) {

      Serial.println("High");

    } else {

      // When sensor changes to low state, we change the state of our output light.

      // This prevents the light from just giva a short flash, but instead remain on or off.

      Serial.println("Low");

      if (state == HIGH) {

        state = LOW;

      } else {

        state = HIGH;

      }

    }

  }

  // Update output light value

  digitalWrite(ledOut, state);

  // Short delay to ensure sensor stability

  delay(1);

}