# Import necessary libraries
import time  # Import the time module for sleep functionality
from machine import Pin  # Import Pin class from machine module for GPIO control
import dht  # Import DHT sensor library
import utime  # Import utime module for precise timing

# Set up GPIO pins
PIR_PIN = 17  # Motion sensor pin
DHT_PIN = 4  # DHT22 sensor pin
TRIG_PIN = 20  # Ultrasonic sensor trigger pin
ECHO_PIN = 12  # Ultrasonic sensor echo pin

# Initialize the motion sensor
pir = Pin(PIR_PIN, Pin.IN, Pin.PULL_DOWN)

# Initialize the DHT22 sensor
dht_sensor = dht.DHT22(Pin(DHT_PIN))

# Initialize the ultrasonic sensor
trig = Pin(TRIG_PIN, Pin.OUT)
echo = Pin(ECHO_PIN, Pin.IN)

print("Starting the program...")

# Function to get distance from ultrasonic sensor
def get_distance():
    # Send a 10us pulse to trigger
    trig.low()
    utime.sleep_us(2)
    trig.high()
    utime.sleep_us(10)
    trig.low()

    # Measure the duration of the echo pulse
    while echo.value() == 0:
        pass
    pulse_start = utime.ticks_us()

    while echo.value() == 1:
        pass
    pulse_end = utime.ticks_us()

    pulse_duration = utime.ticks_diff(pulse_end, pulse_start)
    distance = (pulse_duration / 2) / 29.1  # Divide by 29.1 for distance in cm

    return distance

try:
    # Main program loop
    while True:
        # Read PIR motion sensor
        if pir.value():
            print("Motion detected!")
        else:
            print("No motion.")

        # Read DHT22 sensor
        try:
            dht_sensor.measure()
            temperature = dht_sensor.temperature()
            humidity = dht_sensor.humidity()
            print(f"Temperature: {temperature:.1f}°C, Humidity: {humidity:.1f}%")
        except OSError as e:
            print("Failed to read from DHT sensor.")

        # Read ultrasonic sensor
        try:
            distance = get_distance()
            print(f"Distance: {distance:.2f} cm")
        except OSError as e:
            print("Failed to read from ultrasonic sensor.")

        # Wait 2 seconds before repeating
        time.sleep(2)

except KeyboardInterrupt:
    print("Program stopped.")