#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);  // I2C address 0x27 (from DIYables LCD), 16 column and 2 rows
const int Lsensor = 7;               //Sensor Pin
const int Rsensor = 6;               //Sensor Pin
const int ButtonPin = 13;

const unsigned long debounceDelay = 50;  // Debounce time for the button (in milliseconds)
unsigned long lastDebounceTime = 0;      // Variable to store the last button press time

int Sense1;
int Sense2;
unsigned long NowTime;
unsigned long PastTime = 0;
unsigned long Period = 400;

int initial1 = LOW;
int initial2 = LOW;
int count = 0;  // Counter variable

void setup() {
  Serial.begin(9600);

  lcd.init();       // initialize the lcd
  lcd.backlight();  // open the backlight

  pinMode(Lsensor, INPUT);
  pinMode(Rsensor, INPUT);
  pinMode(ButtonPin, INPUT_PULLUP);
}

void loop() {
  Sense1 = digitalRead(Lsensor);
  Sense2 = digitalRead(Rsensor);
  NowTime = millis();
  //Serial.println(digitalRead(Lsensor));
  if (initial1 != Sense1 && (Period <= NowTime - PastTime)) {
    // Serial.print("initial");
    // Serial.println(initial1);
    // Serial.print("sense");
    // Serial.println(Sense1);
    if (Sense1 == HIGH) {
      count++;
      lcd.clear();
      lcd.setCursor(0, 0);  // start to print at the first row
      lcd.print("Count: ");
      lcd.print(count);
      lcd.print("ft");
      initial1 = HIGH;
    }
    if (Sense1 == LOW) {
      initial1 = LOW;
    }
    PastTime = NowTime;
  }
  if (initial2 != Sense2 && (Period <= NowTime - PastTime)) {
    // Serial.print("initial");
    // Serial.println(initial2);
    // Serial.print("sense");
    // Serial.println(Sense2);
    if (Sense2 == HIGH) {
      count--;
      lcd.clear();
      lcd.setCursor(0, 0);  // start to print at the first row
      lcd.print("Count: ");
      lcd.print(count);
      lcd.print("ft");
      initial2 = HIGH;
    }
    if (Sense2 == LOW) {
      initial2 = LOW;
    }
    PastTime = NowTime;
  }

  if (digitalRead(ButtonPin) == LOW && (NowTime - lastDebounceTime >= debounceDelay)) {
    count = 0;
    lcd.clear();
    lcd.setCursor(0, 0);  // start to print at the first row
    lcd.print("Count: ");
    lcd.print(count);
    lcd.print("ft");
    lastDebounceTime = NowTime;
  }
}