from machine import Pin, PWM, time_pulse_us
import time

# Define LEDs
RED_LED = Pin(3, Pin.OUT)
YELLOW_LED = Pin(4, Pin.OUT)
GREEN_LED = Pin(5, Pin.OUT)

# Define switches
SW1 = Pin(0, Pin.IN, Pin.PULL_DOWN)
SW2 = Pin(1, Pin.IN, Pin.PULL_UP)
SW3 = Pin(2, Pin.IN, Pin.PULL_UP)

# Define ultrasonic sensor pins
TRIG_PIN = Pin(21, Pin.OUT)
ECHO_PIN = Pin(20, Pin.IN)

# Define buzzer
BUZZER = PWM(Pin(27))

# Initial state
gateOpening = False
gateClosing = False
circuitActive = True

def measure_distance():
    # Trigger high for 10us to initiate the measurement
    TRIG_PIN.off()
    time.sleep_us(2)
    TRIG_PIN.on()
    time.sleep_us(10)
    TRIG_PIN.off()

    # Measure the duration of echo pulse
    duration = time_pulse_us(ECHO_PIN, 1, 30000)  # 30ms timeout
    
    # Calculate distance in cm (duration / 2) / 29.1
    distance = (duration / 2) / 29.1
    return distance

def open_gate():
    global gateOpening, gateClosing
    gateOpening = True
    gateClosing = False
    RED_LED.off()
    YELLOW_LED.off()
    
    # Simulate gate opening
    for i in range(10):
        if measure_distance() < 10:  # 10 cm threshold for obstacle detection
            stop_gate_due_to_obstacle()
            return
        GREEN_LED.on()
        time.sleep(0.5)
        GREEN_LED.off()
        time.sleep(0.5)
    GREEN_LED.on()
    gateOpening = False
    play_buzzer_tone(2000, 0.5)  # Play a tone indicating the gate is fully opened

def close_gate():
    global gateOpening, gateClosing
    gateClosing = True
    gateOpening = False
    GREEN_LED.off()
    YELLOW_LED.off()
    
    # Simulate gate closing
    for i in range(10):
        if measure_distance() < 10:  # 10 cm threshold for obstacle detection
            stop_gate_due_to_obstacle()
            return
        RED_LED.on()
        time.sleep(0.5)
        RED_LED.off()
def main():
    measure_distance()
    open_gate()
    close_gate()

main()