Project 2.7.4: Automatic Barrier Gate

Description	This project uses an ultrasonic sensor to detect objects and controls a servo motor to open a barrier gate when something is within 20cm, closing automatically when clear.
Use case	This project can be used in automation systems, interactive installations, and embedded control applications.

Components (Things You will need)

Building the circuit

Things Needed:

• Arduino Uno = 1
• Arduino USB cable = 1
• Ultrasonic sensor = 1
• Servo motor = 1
• Jumper wires

Mounting the component on the breadboard

Step 1: Place the Ultrasonic sensor on the breadboard.

NB: Make sure all components are securely placed on the breadboard with correct orientation.

WIRING THE CIRCUIT

Step 2: Connect the VCC pin of the sensor to the 5V pin on the Arduino using a male-to-male jumper wire.

Step 3: Connect the GND pin of the sensor to the GND pin on the Arduino using a male-to-male jumper wire.

Step 4: Connect the TRIG pin of the ultrasonic sensor to Digital Pin 9 on the Arduino using a male-to-male jumper wire.

Step 5: Connect the ECHO pin of the ultrasonic sensor to Digital Pin 10 on the Arduino using a male-to-male jumper wire.

Step 6: Connect the Signal(yellow/orange) wire of the servo motor to Digital Pin 6 on the Arduino using a male-to-male jumper wire.

Step 7: Connect the VCC (Red) wire to the positive rail on the Arduino on the breadboard using a male-to-male jumper wire as shown in the image.

Since both components require a 5V supply from the single Arduino Uno, connect them using the positive (+) power rail of the breadboard. Jump 5V from the Arduino to the positive rail, then run a power wire from that rail to the servo motor.

Step 7: Connect the GND (Brown/Black) wire to the GND pin on the Arduino using a male-to-male jumper wire.

Make sure to connect the Arduino USB cable to the Arduino board.

PROGRAMMING

Step 1: Open your Arduino IDE. See how to set up here: Getting Started.

Step 2: Type the following code in your Arduino IDE: #include <Servo.h>, const int trigPin = 9;, const int echoPin = 10;, const int servoPin = 6, Servo gateServo;,long duration;, float distance; as shown in the image below.

Step 3: Type the following code in your Arduino IDE inside the void setup() pinMode(trigPin, OUTPUT);, pinMode(echoPin, INPUT);, gateServo.attach(servoPin);, gateServo.write(0);, Serial.begin(9600); as shown in the image below.

Step 4: Type the following code in your Arduino IDE inside the void loop() digitalWrite(trigPin, LOW);, delay(200);, digitalWrite(trigPin, HIGH);, delay(100);, digitalWrite(trigPin, LOW);, duration = pulseIn(echoPin, HIGH);;, distance = duration * 0.0343 / 2;, Serial.print("Distance: ");, Serial.print(distance);, Serial.println(" cm"); as shown in the image below.

Step 5: Type the following code in your Arduino IDE inside the void loop() if (distance > 0 && distance <= 20) {, gateServo.write(90); }, else {, gateServo.write(0); }, delay(200); as shown in the image below.

Uploading the code

Step 1: Save your code. See the Getting Started section

Step 2: Select the Arduino board and port. See the Getting Started section

Step 3: Upload your code.

CONCLUSION

This project helps learners understand how to combine multiple components with Arduino to create more complex interactive systems and automation solutions.