from machine import Pin
import time

# Initialize the PIR sensor, LED, buzzer, and pushbutton
pir_sensor = Pin(16, Pin.IN)       # PIR output pin
led = Pin(17, Pin.OUT)             # LED output pin
buzzer = Pin(18, Pin.OUT)          # Buzzer output pin
pushbutton = Pin(19, Pin.IN, Pin.PULL_DOWN)  # Pushbutton pin with pull-down resistor

# Variables to track alarm state and button press
alarm_state = False
button_last_state = False
button_debounce_time = 0.2  # Debounce delay in seconds

# Function to flash LED and turn on the buzzer
def alarm(intensity=0.2):
    led.toggle()                        # Toggle LED state (on/off)
    buzzer.on()                         # Turn on buzzer
    time.sleep(intensity)               # LED blink delay
    led.toggle()                        # Toggle LED back (off)
    buzzer.off()                        # Turn off buzzer briefly
    time.sleep(intensity)               # Pause between flashes

# Main loop to monitor PIR sensor and pushbutton
while True:
    # Check if button is pressed (with debouncing)
    if pushbutton.value() == 1 and not button_last_state:
        alarm_state = False  # Stop the alarm
        print("Alarm OFF (Button Pressed)")
        time.sleep(button_debounce_time)  # Debounce delay
        button_last_state = True

    # Reset button state after release
    if pushbutton.value() == 0:
        button_last_state = False

    # If the alarm is on (motion detected), activate the alarm function
    if alarm_state:
        alarm()  # Call the alarm function to flash the LED and sound the buzzer

    # Check if motion is detected
    if pir_sensor.value() == 1 and not alarm_state:
        alarm_state = True  # Start the alarm
        print("Motion Detected! Alarm ON")

    time.sleep(0.1)  # Small delay to avoid excessive checks