#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
#define sensor 9
#define start 12
int delay1();

#include <Servo.h>

Servo myservo;  // create servo object to control a servo
// twelve servo objects can be created on most boards

int pos = 0;    // variable to store the servo position

{
  int i,j;
  unsigned int count=0;
  for(i=0;i<1000;i++)
{
  for(j=0;j<1227;j++)
{
  if(digitalRead(sensor))
{
count++;
  while(digitalRead(sensor));
    }
  }
}
  return count;
}
void setup()
{
  Servo myservo; 
  myservo.attach(6);

  pinMode(sensor, INPUT);
  pinMode(start, INPUT);
  lcd.init();                      
  lcd.backlight();
  lcd.setCursor (0,0);
  lcd.print ("   Activated...    ");
  delay(1000);
  lcd.clear();
  lcd.setCursor (0,0);
  lcd.print ("Initiating...");
  delay (500);
  lcd.setCursor (2,3);
  lcd.print ("119290081");
  delay (700);
  lcd.clear();
  lcd.print("---Tachometer---");
    delay (500);
  lcd.setCursor (1,1);
  lcd.print ("Welcome Taufik");
  delay(1000);
  digitalWrite(start, HIGH);
}
void loop()
{
  unsigned int time=0,RPM=0;
  lcd.clear();
  lcd.print(" Please Press ");
  lcd.setCursor(1,1);
  lcd.print("Button to Start ");
  delay (800);
  while(digitalRead(start));
  lcd.clear();

  for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
    // in steps of 1 degree
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }
  for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
    myservo.write(pos);              // tell servo to go to position in variable 'pos'
    delay(15);                       // waits 15ms for the servo to reach the position
  }

  lcd.print("Reading RPM.....");
  time=delay1();
  lcd.clear();
  lcd.print("Please Wait.....");
  RPM=(time*12)/3;
  delay(2000);
  lcd.clear();
  lcd.print("RPM=");
  lcd.print(RPM);
  delay(5000);
}