Week 6 - Journal

Used various electrical components:

• 2x - 330 ohm resistor - Limit current across LED

• 1x - IR Sensor - Detects objects in-front of it

• DC 9 Volt power supply - Power up everything

• Jumper wires - Connect components on the breadboard

• 1x - Small breadboard - Acts as the common connection between components

• 2x - LEDs - Output to indicate the device is working

• 1x - Stepper Motor - Open and close the gate

• 1x - 5V Buzzer

• 1x HC-SR04 ultrasonic - Check if a car is waiting in-front of the gate

• Arduino Uno - Main brain of the circuit

Circuit Documentation

This project uses a IR sensor, an ultrasonic sensor, and a servo motor to make an automatic gate system. The servo acts as the gate, and it opens or closes depending on the sensor readings.

The ultrasonic sensor measures distance. If something is closer than 15 cm, the servo turns to open the gate by rotating the servo from 100 degrees to 180 degrees. At the same time, the green LED turns ON and the buzzer goes off to indicate that the gate is open.

Once the car goes in The IR sensor checks for movement when the car reaches the sensor the gate closes and stays closed till the car starts leaving and the red LED is ON. When motion is detected of the car leaving the gate opens for 5 seconds, then closes again and waits 3 seconds before checking for new cars.

Components Used

• 1 × Ultrasonic Sensor – measures distance of objects (like cars) near the gate to open it.

• 1 × IR Sensor – detects motion to decide when the gate should open or close.

• 1 × Servo Motor – acts as the gate, moving between open and closed positions.

• 1 × LEDs – green LEDs that turn ON when the gate is open.

• 1 × LED – red LED that lights up when the gate is closed.

• 1 × Arduino Board – controls the whole system.

Code Blocks Explaination

1. forever loop keeps program running

2. pir sensor on pin 3 reads if motion is detected or not

3. ultrasonic sensor on trigger pin 7 and echo pin 6 measures distance in cm if object is 15 cm or less it rotates servo to 180 and sets pin 10 and 11 high and pin 8 low

4. if pir sensor equals 1 then servo rotates to 100 degrees gate opens it keeps checking until pir sensor goes back to 0 during this time pin 10 and 11 are set low and pin 8 high

5. after motion detected gate stays open for 5 seconds servo goes to 180 then gate closes servo back to 100 waits 3 seconds before checking again

6. on start servo is set to 100 degrees as default closed position