//RANGE FINDER

#include "U8glib.h"

#define trig 2
#define echo 3

U8GLIB_SSD1306_128X64 u8g(U8G_I2C_OPT_DEV_0 | U8G_I2C_OPT_NO_ACK | U8G_I2C_OPT_FAST); // Fast I2C / TWI

void setup(){}

void loop() 
{
  float distanceIN = getDistance();
  if (distanceIN > 12)
  {
    float distanceFT = distanceIN / 12.0;
    float remainder = (int)distanceIN % 12;
    u8g.firstPage();
    do {
      char buf [10];
      String rangeStr = String(distanceFT) + "ft " + String(remainder) + "in        ";
      rangeStr.toCharArray(buf, rangeStr.length());
      u8g.drawStr(28, 28, buf);
    } while ( u8g.nextPage() );
  }
  else
  {
    u8g.firstPage();
    do {
      char buf [10];
      String rangeStr = String(distanceIN) + "in            ";
      rangeStr.toCharArray(buf, rangeStr.length());
      u8g.drawStr(28, 28, buf);
    } while ( u8g.nextPage() );
  }
}

float getDistance()
{
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);

  float duration = pulseIn(echo, HIGH);
  float distanceCM = 0.017 * duration;
  return distanceCM * 0.3937008;
}