The Wave Switch

CIRCUIT

CODE

// The Wave Switch

const int trigPin = 2;

const int echoPin = 4;

int redPin = 6;

void setup() 

{

  Serial.begin(9600);

}

void loop()

{

  long duration, inches, cm;

  pinMode(trigPin, OUTPUT);

  digitalWrite(trigPin, LOW);

  delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);

  delayMicroseconds(10);

  digitalWrite(trigPin, LOW);

  pinMode(echoPin, INPUT);

  pinMode(redPin, OUTPUT);

  

  duration = pulseIn(echoPin, HIGH);

  inches = microsecondsToInches(duration);

  cm = microsecondsToCentimeters(duration);

  

  if (cm > 40 && cm < 80){

    digitalWrite(redPin, HIGH);}

    

  if (cm < 40){

    digitalWrite(redPin, LOW);}

   

  Serial.print(inches);

  Serial.print("in, ");

  Serial.print(cm);

  Serial.print("cm");

  Serial.println();

  

  delay(100);

}

long microsecondsToInches(long microseconds){

  return microseconds / 74 / 2;

}

long microsecondsToCentimeters(long microseconds){

  return microseconds / 29 / 2;

}