import serial
import time

class co2Sensor:

    def __init__(self):
        self.ser = serial.Serial("/dev/ttyAMA0", baudrate=9600, timeout=1)
        self.ser.flushInput()

    def readCO2Level(self):
        try:
            command = bytes([0xFE, 0x44, 0x00, 0x08, 0x02, 0x9F, 0x25])
            self.ser.write(command)
            time.sleep(0.1)
            resp = self.ser.read(7)
            if len(resp) != 7:
                raise ValueError("Réponse incomplète du capteur")

            high = resp[3]
            low = resp[4]
            co2 = (high << 8) | low
            return co2
        except Exception as e:
            raise RuntimeError(f"Erreur de lecture du capteur CO2: {e}")