DontForgetTheSoap

//reference: https://itp.nyu.edu/physcomp/labs/motors-and-transistors/using-a-transistor-to-control-high-current-loads-with-an-arduino/
//reference:  http://www.tautvidas.com/blog/2012/08/distance-sensing-with-ultrasonic-sensor-and-arduino/
//reference: https://www.arduino.cc/en/Tutorial/Ping
//reference: http://art-research2010summer.blogspot.com.es/2010/06/tutorial-01-isadora-and-arduino.html


const int trigPin = 12;
const int echoPin = 13;

void setup() {
  Serial.begin (9600);


}

void loop() {
  //trigger/pulse
  long duration, inches, cm;
  pinMode(trigPin, OUTPUT);
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  //read sensor
  pinMode(echoPin, INPUT);
  duration = pulseIn(echoPin, HIGH, 185000);

  //convert time to distance
  inches = microsecondsToInches (duration);
  cm = microsecondsToCentimeters (duration);
  Serial.println(cm);
  delay(100);

  Serial.println(1, DEC);
  Serial.println(cm);
  delay(10);


  long microsecondsToInches (long microseconds) {
    return microseconds / 74 / 2;
  }
  long microsecondsToCentimeters (long microseconds) {
    return microsecond