from machine import Pin, ADC, PWM
import time

gas = ADC(Pin(26))      # Sensor on GP26
buzzer = PWM(Pin(15))   # Buzzer on GP15

while True:
    val = gas.read_u16()
    print("Level:", val)

    if val > 20000:     # If gas is detected
        buzzer.freq(1000)
        buzzer.duty_u16(32768)
        time.sleep(0.1)
        buzzer.duty_u16(0)
    else:
        buzzer.duty_u16(0)

    time.sleep(0.5)