/*

Voltaat learn (http://learn.voltaat.com)

Link for full tutorial:

Tutorial: How_to_make_an_automatic_opening_gate_for_a_car_garage!

The purpose of this sketch is to How to build a garage gate that

opens and closes automatically when a car passes in front of it

using an Arduino board..

Connections from the Arduino to the breadboard:

• Arduino GND pin → Breadboard ground line

• Arduino 5V pin → Breadboard 5V line

Connection from the LCD:

• VCC pin → breadboard 5v line

• GND pin→ breadboard GND line

• SDA pin→ Arduino analog pin A4

• SCL pin → Arduino analog pin A5

Connections from the ultrasonic sensor:

• ultrasonic sensor VCC pin → Breadboard 5V line

• ultrasonic sensor GND pin → Breadboard ground line

• ultrasonic sensor Trig pin → Arduino pin 2

• ultrasonic sensor Echo pin → Arduino pin 3

Connections from the servo motor:

• Servo GND pin → Breadboard ground line

• Servo VCC pin → Breadboard 5V line

• Servo signal pin → Arduino pin 5

*/

#include "Servo.h"

#include "LiquidCrystal_I2C.h"

Servo servo;

int trigPin = 2;

int echoPin = 3;

// defines variables

long duration;

int distance;

// Initialize the LCD with I2C address 0x27 (common for many LCDs) and 16x2 size

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup()

{

  servo.attach(5);

  servo.write(180);

  delay(2000);

  // Sets the trigPin as an Output

  pinMode(trigPin, OUTPUT);

  // Sets the echoPin as an Input

  pinMode(echoPin, INPUT);

  // Initialize the LCD

  lcd.begin(16,2);

  lcd.backlight();

  lcd.setCursor(0, 0);

  lcd.print("  System Ready");

  delay(2000);

}

void loop()

{

  // Clears the trigPin

  digitalWrite(trigPin, LOW);

  delayMicroseconds(2);

  // Sets the trigPin on HIGH state for 10 microseconds

  digitalWrite(trigPin, HIGH);

  delayMicroseconds(10);

  digitalWrite(trigPin, LOW);

  // Reads the echoPin, returns the sound wave travel time in microseconds

  duration = pulseIn(echoPin, HIGH);

  // Calculating the distance

  distance = duration * 0.034 / 2;

  // Prints the distance on the LCD

  if (distance <= 25)  // Change distance according to Ultrasonic Sensor Placement

  {

    servo.write(180);  // Open the gate

    lcd.setCursor(0, 0);

    lcd.print(" Gate is opened");

    delay(3000);

  }

  else

  {

    // Gradually close the gate slowly

    servo.write(90);

    lcd.setCursor(0, 0);

    lcd.print(" Gate is closed ");

  }

}

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