Ultrasonic Sensor with LED's bar graph and buzzer, you can see the full project at my website http://randomnerdtutorials.wordpress.com

Ultrasonic Sensor with LED's bar graph and buzzer

/*
 * created by Rui Santos, http://randomnerdtutorials.wordpress.com
 * Ultrasonic Sensor with LED's bar graph and buzzer 
 * 2013
 */
int tonePin = 4;    //Tone - Red Jumper
int trigPin = 9;    //Trig - violet Jumper
int echoPin = 10;   //Echo - yellow Jumper
int clockPin = 11;  //IC Pin 11 - white Jumper
int latchPin = 12;  //IC Pin 12 - Blue Jumper
int dataPin = 13;   //IC Pin 14 - Green Jumper

byte possible_patterns[9] = {
B00000000, 
B00000001,
B00000011,
B00000111,
B00001111,
B00011111,
B00111111, 
B01111111, 
B11111111,
};
int proximity=0;
int duration;
int distance;

void setup() {
  //Serial Port
  Serial.begin (9600);
  
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
  pinMode(tonePin, OUTPUT);
}

void loop() {
  digitalWrite(latchPin, LOW);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(1000);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = (duration/2) / 29.1;
  
  /*if (distance >= 45 || distance <= 0){
    Serial.println("Out of range");
  }
  else {
    Serial.print(distance);
    Serial.println(" cm");
  }*/
  
  proximity=map(distance, 0, 45, 8, 0);
  //Serial.println(proximity);
  
  if (proximity <= 0){
    proximity=0;
  }
  else if (proximity >= 3 && proximity <= 4){
    tone(tonePin, 200000, 200);
  }
  else if (proximity >= 5 && proximity <= 6){
     tone(tonePin,5000, 200);
  }
  else if (proximity >= 7 && proximity <= 8){
    tone(tonePin, 1000, 200);
  }
  shiftOut(dataPin, clockPin, MSBFIRST, possible_patterns[proximity]);
  digitalWrite(latchPin, HIGH);

  
  delay(600);
  noTone(tonePin);
}