MQ Unit

This is the driver library of MQ Unit, which is used to obtain data from the MQ sensor.

Support the following products:

UiFlow2 Example

get MQ ADC value

Open the mq_core2_example.m5f2 project in UiFlow2.

This example gets the ADC value of the MQ Unit and displays it on the screen.

UiFlow2 Code Block:

Example output:

None

MicroPython Example

get MQ ADC value

This example gets the ADC value of the MQ Unit and displays it on the screen.

MicroPython Code Block:

# SPDX-FileCopyrightText: 2025 M5Stack Technology CO LTD
#
# SPDX-License-Identifier: MIT

import os, sys, io
import M5
from M5 import *
import m5ui
import lvgl as lv
from hardware import I2C
from hardware import Pin
from unit import MQUnit


page0 = None
label0 = None
label1 = None
label2 = None
i2c0 = None
mq_0 = None


valid = None


def setup():
    global page0, label0, label1, label2, i2c0, mq_0, valid

    M5.begin()
    Widgets.setRotation(1)
    m5ui.init()
    page0 = m5ui.M5Page(bg_c=0xFFFFFF)
    label0 = m5ui.M5Label(
        "Valid Flag:",
        x=1,
        y=76,
        text_c=0x000000,
        bg_c=0xFFFFFF,
        bg_opa=0,
        font=lv.font_montserrat_16,
        parent=page0,
    )
    label1 = m5ui.M5Label(
        "ADC 8bits:0",
        x=1,
        y=111,
        text_c=0x000000,
        bg_c=0xFFFFFF,
        bg_opa=0,
        font=lv.font_montserrat_16,
        parent=page0,
    )
    label2 = m5ui.M5Label(
        "ADC 12bits:0",
        x=1,
        y=145,
        text_c=0x000000,
        bg_c=0xFFFFFF,
        bg_opa=0,
        font=lv.font_montserrat_16,
        parent=page0,
    )

    i2c0 = I2C(0, scl=Pin(33), sda=Pin(32), freq=100000)
    mq_0 = MQUnit(i2c0, 0x11)
    mq_0.set_mq_mode(1)
    page0.screen_load()


def loop():
    global page0, label0, label1, label2, i2c0, mq_0, valid
    M5.update()
    valid = mq_0.get_valid_tags()
    if valid:
        label0.set_text(str((str("Valid Flag:") + str(valid))))
        label1.set_text(str((str("ADC 8bits:") + str((mq_0.get_adc_value(0))))))
        label2.set_text(str((str("ADC 12bits:") + str((mq_0.get_adc_value(1))))))
    else:
        label0.set_text(str("Valid Flag: Wait heating"))


if __name__ == "__main__":
    try:
        setup()
        while True:
            loop()
    except (Exception, KeyboardInterrupt) as e:
        try:
            m5ui.deinit()
            from utility import print_error_msg

            print_error_msg(e)
        except ImportError:
            print("please update to latest firmware")

Example output:

None

API

MQUnit

class unit.mq.MQUnit(i2c, address=17)

Bases: object

Create a MQUnit object.

Parameters:

i2c (I2C) – The I2C bus the MQ Unit is connected to.
address (int) – The I2C address of the device. Default is 0x11.

UiFlow2 Code Block:

MicroPython Code Block:

from hardware import I2C
from unit import MQUnit

i2c0 = I2C(0, scl=Pin(1), sda=Pin(2), freq=100000)
tof_0 = MQUnit(i2c0)

set_mq_mode(mode=1)

Set the working mode of the MQ sensor.

Parameters:: mode (int) – Working mode value.

Option:

0 : Measurement off
1 : Continuous heating mode
2 : Pin Level Switching Mode

UiFlow2 Code Block:

MicroPython Code Block:

mq_0.set_mq_mode(1)

get_mq_mode()

Get the current working mode of the MQ sensor.

Returns:: Current working mode value.
Return type:: int

UiFlow2 Code Block:

MicroPython Code Block:

mode = mq_0.get_mq_mode()

set_led_status(status)

Set the LED status.

Parameters:: status (int) – When the LED is set to on, it lights up when a valid tag is detected, and the brightness is proportional to the ADC value, and it turns off when no tag is detected.

MicroPython Code Block:

mq_0.set_led_status(1)

get_led_status()

Get the LED status.

Returns:: True if LED status is on, False otherwise.
Return type:: bool

MicroPython Code Block:

led_on = mq_0.get_led_status()

set_heat_time(high_level_time=30, low_level_time=5)

Set heater high and low level time.

Parameters:

high_level_time (int) – Time for high heating level.
low_level_time (int) – Time for low heating level.

UiFlow2 Code Block:

MicroPython Code Block:

mq_0.set_heat_time(30, 5)

get_heat_time()

Get heater high and low level time.

Returns:: [high_level_time, low_level_time]
Return type:: [int, int]

MicroPython Code Block:

times = mq_0.get_heat_time()

get_adc_value(precision)

Get ADC value.

Parameters:: precision (int) – 0 for 8-bit, 1 for 12-bit.
Returns:: ADC value.
Return type:: int

UiFlow2 Code Block:

MicroPython Code Block:

value = mq_0.get_adc_value(1)

get_valid_tags()

Check if valid tags are detected.

Returns:: True if valid tags detected, False otherwise.
Return type:: bool

UiFlow2 Code Block:

MicroPython Code Block:

valid = mq_0.get_valid_tags()

get_ntc_adc_value(precision)

Get internal NTC ADC value.

Parameters:: precision (int) – 0 for 8-bit, 1 for 12-bit.
Returns:: NTC ADC value.
Return type:: int

MicroPython Code Block:

ntc = mq_0.get_ntc_adc_value(1)

get_ntc_res_value()

Get internal NTC resistance value.

Returns:: Resistance value.
Return type:: int

MicroPython Code Block:

res = mq_0.get_ntc_res_value()

get_voltage(channle)

Get voltage value from a specific channel.

Parameters:: channle (int) – Channel number.
Returns:: Voltage value.
Return type:: int

MicroPython Code Block:

voltage = mq_0.get_voltage(0)

get_firmware_version()

Get firmware version.

Returns:: Firmware version.
Return type:: int

UiFlow2 Code Block:

MicroPython Code Block:

ver = mq_0.get_firmware_version()

get_i2c_address()

Get current I2C address.

Returns:: MQ Unit I2C address, Default is 0x11.
Return type:: int

UiFlow2 Code Block:

MicroPython Code Block:

addr = mq_0.get_i2c_address()

set_i2c_address(addr)

Set new I2C address.

Parameters:: addr (int) – New I2C address (0x08~0x77).

UiFlow2 Code Block:

MicroPython Code Block:

mq_0.set_i2c_address(0x3A)