from machine import ADC, Pin
import time

# --- MQ-2 Pins ---
mq2_analog = ADC(26)   # GP26 = AO (analog output)
mq2_digital = Pin(15, Pin.IN)  # GP15 = DO (digital output)

# --- Buzzer Pin ---
buzzer = Pin(14, Pin.OUT)  # GP14 for buzzer

# Function to read analog gas level
def read_gas():
    raw_value = mq2_analog.read_u16()  # 0-65535
    voltage = raw_value * 3.3 / 65535  # Convert to voltage
    return raw_value, voltage

# Main loop
while True:
    raw, volt = read_gas()
    
    # Simple analysis thresholds (adjust as needed)
    if raw < 20000:
        gas_level = "Low"
        buzzer.value(0)  # Turn OFF buzzer
    elif raw < 40000:
        gas_level = "Medium"
        buzzer.value(0)  # Turn OFF buzzer
    else:
        gas_level = "High"
        buzzer.value(1)  # Turn ON buzzer
    
    # Digital alert (optional display)
    alert = "🚨 Gas above threshold!" if mq2_digital.value() == 1 else "Safe"
    
    # Print status
    print(f"Raw: {raw}, Voltage: {volt:.2f} V, Gas Level: {gas_level}, Alert: {alert}")
    
    time.sleep(1)