#include <LiquidCrystal.h>
#include <Servo.h>

#define ECHO_PIN 2
#define TRIG_PIN 3

LiquidCrystal lcd(12, 11, 10, 9, 8, 7);

Servo servo1;
float pos = 180.0;
float step = 1.0;

void setup() {
Serial.begin(115200);
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  lcd.begin(16, 2);
  lcd.print("Starting up");
  delay(2000);
  servo1.attach(5);
  servo1.write(pos);

}

float readDistanceCM() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  int duration = pulseIn(ECHO_PIN, HIGH);
  return duration * 0.034 / 2;
}

void loop() {
  int option = 3;
  float distance = readDistanceCM();

  // bool isNearby = distance < 150;
  // digitalWrite(LED_BUILTIN, isNearby);

  Serial.print("Measured distance: ");
  Serial.println(readDistanceCM());

  if (distance < 150){
    while (pos >= 90){
      lcd.clear();
      lcd.print("Opening");
      digitalWrite(LED_BUILTIN, HIGH);
      servo1.write(pos);
      pos-=step;
      delay(40);
    }
    lcd.clear();
    digitalWrite(LED_BUILTIN, LOW);
    lcd.print("Opened");
    delay(150);
  }
  else{
    while (pos <= 180){
      lcd.clear();
      lcd.print("Closing");
      digitalWrite(LED_BUILTIN, HIGH);
      servo1.write(pos);
      pos+=step;
      delay(40);
    }
    lcd.clear();
    digitalWrite(LED_BUILTIN, LOW);
    lcd.print("Closed");
    delay(150);
  }
}