from machine import Pin, PWM
import utime
import dht

# Initialize DHT sensor (DHT22 on GP15)
dht_sensor = dht.DHT22(Pin(15))

# Initialize passive buzzer on GP16 with PWM
buzzer = PWM(Pin(16))

# Temperature threshold
TEMP_THRESHOLD = 30

def sound_buzzer(frequency=1000, duration=0.5):
    """Sound the passive buzzer at a given frequency for a set duration (in seconds)."""
    buzzer.freq(frequency)
    buzzer.duty_u16(30000)  # 50% duty cycle approx
    utime.sleep(duration)
    buzzer.duty_u16(0)  # Turn off buzzer

while True:
    try:
        dht_sensor.measure()
        temp = dht_sensor.temperature()
        
        print("Temperature: {:.1f}C".format(temp))
        
        if temp > TEMP_THRESHOLD:
            print("!! Temperature HIGH !! Alarm Triggered")
            sound_buzzer(frequency=2000, duration=0.2)  # Beep at 2kHz for 0.2s
            utime.sleep(0.3)  # Short pause between beeps
        else:
            buzzer.duty_u16(0)  # Ensure buzzer is off

    except OSError as e:
        print("Failed to read from DHT sensor:", e)

    utime.sleep(2)