ME007

gistfile1.ino

#include <LiquidCrystal.h>
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);
const int pingPin = 9;
const int ledPin=13;

void setup() {
  // initialize serial communication:
  Serial.begin(9600);
  lcd.begin(16, 2);
  
}

void loop()
{
 
  long duration, inches, cm;
  pinMode(pingPin, OUTPUT);
  pinMode(ledPin, OUTPUT);
  digitalWrite(ledPin, LOW);
  digitalWrite(pingPin, LOW);
  delayMicroseconds(2);
  digitalWrite(pingPin, HIGH);
  delayMicroseconds(5);
  digitalWrite(pingPin, LOW);

  pinMode(pingPin, INPUT);
  duration = pulseIn(pingPin, HIGH);

  inches = microsecondsToInches(duration);
  cm = microsecondsToCentimeters(duration);
  

  delay(500);
  Serial.print("in, ");
  Serial.print(cm);
  Serial.print("cm");
  Serial.println();
  if(inches<=20)
  {
  digitalWrite(ledPin, HIGH);
 lcd.clear();
  lcd.print("Distance:");
  lcd.print(inches);
  lcd.setCursor(0,1);
  
  lcd.print("Sensor Activated");
  Serial.print("Sensor activated");
  Serial.print(inches);
  delay(500);
  }
  else
  {
    lcd.clear();
  lcd.setCursor(0,1);
  
  lcd.print("Sensor OFF");
  Serial.println("Sensor OFF");
  
  }
  delay(100);
}

long microsecondsToInches(long microseconds)
{
  
  // According to Parallax's datasheet for the PING))), there are
  // 73.746 microseconds per inch (i.e. sound travels at 1130 feet per
  // second).  This gives the distance travelled by the ping, outbound
  // and return, so we divide by 2 to get the distance of the obstacle.
  // See: http://www.parallax.com/dl/docs/prod/acc/28015-PING-v1.3.pdf
  return microseconds / 74 / 2;
}

long microsecondsToCentimeters(long microseconds)
{
  // The speed of sound is 340 m/s or 29 microseconds per centimeter.
  // The ping travels out and back, so to find the distance of the
  // object we take half of the distance travelled.
  return microseconds / 29 / 2;
}