//Lab14 Ultrasonic_sensor+LCd
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,20,4);
// set the LCD address to 0x27 for a 16 chars and 2 line display
float cm;
float inches;
long readUltrasoniststance(int triggerPin, int echoPin)
{
  pinMode(triggerPin, OUTPUT); // Clear the trigger
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  // sets the trigger pin HTGH state for 10 microseconds
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  pinMode(echoPin, INPUT);
  //Reads the echo pin, and returns
  // the sound wave travel time in microseconds
  return pulseIn(echoPin, HIGH);
}
void setup() {
  Serial.begin(9600);
  lcd.init(); // initialize the lcd
  // Print a message to the LCD.
  lcd.backlight();
  lcd.print("-->Distance <--");
  delay(3000);
  lcd.clear();
}

void loop() 
{
  cm = 0.0344/2 * readUltrasoniststance(3, 2);
  inches = (cm/2.54);
  /*
  Serial.print("Inches");
  Serial.print(inches,1);
  Serial.print("\t");
  Serial.print("cm");
  Serial.print(cm,1);
  */
  lcd.setCursor(0,0);
  lcd.print("Inches");
  lcd.setCursor(4,0);
  lcd.setCursor(12,0);
  lcd.print("cm");
  lcd.setCursor(1,1);
  lcd.print(inches,1);
  lcd.setCursor(11,1);
  lcd.print(cm,1);
  lcd.setCursor(14,1);
  delay(2000);
  lcd.clear();
}