mh_z19.py

# mh_z19.py

import struct
import utime
from machine import UART

class MHZ19:
    """
    MH-Z19C CO2 Sensor Driver

    Args:
        uart_id (int): UART identifier (e.g., 1 for UART1)
        uart (UART): UART object
    """

    def __init__(self, uart_id=1, uart=None):
        self.uart = uart or UART(uart_id, baudrate=9600, tx=4, rx=5)
        utime.sleep(1)  # Allow sensor to initialize

    def read(self):
        # Example implementation; modify based on your sensor's protocol
        self.uart.write(b'\xff\x01\x86\x00\x00\x00\x00\x00\x79')
        utime.sleep(0.1)
        response = self.uart.read()
        if response and len(response) >= 9:
            co2 = response[2] * 256 + response[3]
            temp = response[4] - 40
            return {'co2': co2, 'temperature': temp}
        return {'co2': None, 'temperature': None}