from machine import Pin, ADC
import time

# Setup pins
pir = Pin(15, Pin.IN)
fan_led = Pin(2, Pin.OUT)

# MQ-2 connected to ADC GPIO34
mq2 = ADC(Pin(34))
mq2.atten(ADC.ATTN_11DB)  # Full range: 0-3.3V

# Threshold for high gas detection (adjust based on calibration)
GAS_THRESHOLD = 2000  # Example threshold value (ADC units)

while True:
    gas_value = mq2.read()
    person_present = pir.value() == 1
    
    print(f"Gas Level: {gas_value}, Person Present: {person_present}")
    
    if gas_value > GAS_THRESHOLD and person_present:
        fan_led.on()   # Turn fan ON
    else:
        fan_led.off()  # Turn fan OFF
    
    time.sleep(1)