#define pirPin A2
int calibrationTime = 30;
long unsigned int lowIn;
long unsigned int pause = 50;
boolean lockLow = true;
boolean takeLowTime;
int PIRValue = 0;

#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27,16,2);

void setup() {
   lcd.init();
   Serial.begin(9600);
   pinMode(pirPin, INPUT);
}

void loop() {
  lcd.backlight();
   if(digitalRead(pirPin) == HIGH) {
      if(lockLow) {
         PIRValue = 1;
         lockLow = false;
         Serial.println("Motion detected.");
         lcd.clear();
         lcd.setCursor(0,0);
         lcd.print("Motion detected");
         delay(1);
      }
      takeLowTime = true;
   }
   if(digitalRead(pirPin) == LOW) {
      if(takeLowTime){
         lowIn = millis();takeLowTime = false;
      }
      if(!lockLow && millis() - lowIn > pause) {
         PIRValue = 0;
         lockLow = true;
         Serial.println("Motion ended.");
         lcd.clear();
         lcd.setCursor(0,0);
         lcd.print("Motion ended.");
         delay(1);
      }
   }
}