print("Project: Goal 9 (Industries, Inovation & Infrastructure)")
print("Dateline: 22/11/2024")
print("Created By: Jd")



#Import Libraries

from machine import Pin, PWM
from time import sleep



#Pin Declaration

ir_sensor_approach = Pin(15, Pin.IN)  # IR sensor to detect approaching train (orange)
ir_sensor_depart = Pin(16, Pin.IN)   # IR sensor to detect departing train (yellow)
servo_pin = PWM(Pin(4))              # Servo motor control pin
red_led = Pin(18, Pin.OUT)           # Red LED for closed gate
green_led = Pin(19, Pin.OUT)         # Green LED for open gate
buzzer = PWM(Pin(21))                # Buzzer configured as PWM



# Servo motor configuration

servo_pin.freq(50)

def set_servo_angle(angle):
    """Set servo motor to a specific angle."""
    duty = int((angle / 180.0 * 102) + 26)  # Map angle to duty cycle (26-128)
    servo_pin.duty(duty)



# Buzzer functions

def buzzer_on():
    """Turn the buzzer on by setting a duty cycle."""
    buzzer.freq(1000)  # Set the buzzer frequency (e.g., 1 kHz)
    buzzer.duty(512)   # 50% duty cycle for sound

def buzzer_off():
    """Turn the buzzer off by setting the duty cycle to zero."""
    buzzer.duty(0)



#Main Program

set_servo_angle(90)  # Open gate
red_led.off()
green_led.on()
print("System ready. Gate is open.")

try:
    while True:
        # Check if train is approaching
        if ir_sensor_approach.value() == 0:  # IR sensor detects train
            print("Train approaching! Closing gate.")
            green_led.off()
            red_led.on()
            
            # Warning sound
            for _ in range(5):
                buzzer_on()
                sleep(0.2)
                buzzer_off()
                sleep(0.2)
            
            # Close the gate
            set_servo_angle(0)  # Gate closed
            print("Gate is closed.")

        # Check if train has departed
        if ir_sensor_depart.value() == 0:  # IR sensor detects train departure
            print("Train departed. Opening gate.")
            red_led.off()
            green_led.on()
            
            # Open the gate
            set_servo_angle(90)  # Gate open
            print("Gate is open.")
        
        sleep(0.1)  # Short delay to prevent rapid polling

except KeyboardInterrupt:
    print("System shutting down.")
    # Reset state
    set_servo_angle(90)  # Ensure gate is open
    red_led.off()
    green_led.on()
    buzzer_off()