Fermion: MEMS Gas Sensor - MiCS-5524 -DFRobot Product wiki

Introduction

This is a hydrogen and nitrogen oxide gas concentration sensor launched by DFRobot. The sensor uses MEMS technology to support gas concentration detection of CO, CH4, C2H5OH, C3H8, C4H10, H2, H2S and NH3. The matching sample code integrates the concentration conversion formula of various gas to facilitate the testing and use of sensors. The product supports 5V power supply, analog voltage output, and has power supply enable/disable pins for low power consumption.

Features

Specification

Board Overview

No. Name Function
1 5V +
2 GND -
3 A0 Analog quantity output
4 EN Power Supply diable/enable pin(enable at a low level，disable at a high level)

Tutorial for Arduino use

Download the program to the UNO, open Serial Port Monitor to view the gas concentration, raw data, and other parameters.

Software and hardware preparation

Connection Diagram

Sample 1 - Read the gas concentration(PPM) data calculated by the sensor

Download the sample program to the Arduino UNO, and open Serial Port Monitor for viewing the NO2 gas concentration (PPM) data.

Steps

 /*!
  * @file  getGasPPM.ino
  * @brief Reading Gas concentration, A concentration of one part per million (PPM).
  * @n When using IIC device, select I2C address, set the dialing switch A0, A1 (Address_0 is [0 0]), (Address_1 is [1 0]), (Address_2 is [0 1]), (Address_3 is [1 1]).
  * @n When using the Breakout version, connect the adcPin and PowerPin
  * @copyright   Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
  * @licence     The MIT License (MIT)
  * @author      ZhixinLiu(zhixin.liu@dfrobot.com)
  * @version     V1.1
  * @date        2021-04-19
  * @get         from https://www.dfrobot.com
  * @url         https://github.com/dfrobot/DFRobot_MICS
  */
#include "DFRobot_MICS.h"

#define CALIBRATION_TIME   3                      // Default calibration time is three minutes

// When using the Breakout version, use the following program to construct an object from DFRobot_MICS_ADC
/**!
  adcPin is A0~A5
  powerPin is General IO
*/
#define ADC_PIN   A0
#define POWER_PIN 10
DFRobot_MICS_ADC mics(/*adcPin*/ADC_PIN, /*powerPin*/POWER_PIN);

void setup() 
{
  Serial.begin(115200);
  while(!Serial);
  while(!mics.begin()){
    Serial.println("NO Deivces !");
    delay(1000);
  } Serial.println("Device connected successfully !");

  /**!
    Gets the power mode of the sensor
    The sensor is in sleep mode when power is on,so it needs to wake up the sensor. 
    The data obtained in sleep mode is wrong
   */
  uint8_t mode = mics.getPowerState();
  if(mode == SLEEP_MODE){
    mics.wakeUpMode();
    Serial.println("wake up sensor success!");
  }else{
    Serial.println("The sensor is wake up mode");
  }

  /**!
     Do not touch the sensor probe when preheating the sensor.
     Place the sensor in clean air.
     The default calibration time is 3 minutes.
  */
  while(!mics.warmUpTime(CALIBRATION_TIME)){
    Serial.println("Please wait until the warm-up time is over!");
    delay(1000);
  }
}

void loop() 
{
  /**!
    Gas type:
    MICS-4514 You can get all gas concentration
    MICS-5524 You can get the concentration of CH4, C2H5OH, H2, NH3, CO
    MICS-2714 You can get the concentration of NO2
      Methane          (CH4)    (1000 - 25000)PPM
      Ethanol          (C2H5OH) (10   - 500)PPM
      Hydrogen         (H2)     (1    - 1000)PPM
      Ammonia          (NH3)    (1    - 500)PPM
      Carbon Monoxide  (CO)     (1    - 1000)PPM
      Nitrogen Dioxide (NO2)    (0.1  - 10)PPM
  */
  float gasdata = mics.getGasData(C2H5OH);
  Serial.print(gasdata,1);
  Serial.println(" PPM");
  delay(1000);
  //mics.sleepMode();
}

Result

Open the serial port monitor and warm up for approximately 3 minutes to obtain the alcohol (C2H5OH) gas concentration data.

Notes：

Sample 2 - Detection of Gas Leakage

The MEMS chip MiCS-5524 reacts to the NO2, H2 and NO gas, but the linearity of some gas concentration feedback value is poor. Therefore, the concentration value does not have a reference value, but can be used as the determination basis of the gas leakage.

If you need a leak detection of the relevant gas, you can download the sample program to the Arduino UNO, open Serial Port monitor to see if the set gas is leaking.

Steps

 /*!
  * @file  getGasExist.ino
  * @brief Reading Gas concentration, A concentration of one part per million (PPM).
  * @n When using IIC device, select I2C address, set the dialing switch A0, A1 (Address_0 is [0 0]), (Address_1 is [1 0]), (Address_2 is [0 1]), (Address_3 is [1 1]).
  * @n When using the Breakout version, connect the adcPin and PowerPin
  * @copyright   Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
  * @licence     The MIT License (MIT)
  * @author      ZhixinLiu(zhixin.liu@dfrobot.com)
  * @version     V1.1
  * @date        2021-04-19
  * @get         from https://www.dfrobot.com
  * @url         https://github.com/dfrobot/DFRobot_MICS
  */
#include "DFRobot_MICS.h"
#define CALIBRATION_TIME   3                      // Default calibration time is three minutes
// When using the Breakout version, use the following program to construct an object from DFRobot_MICS_ADC/**!
  adcPin is A0~A5
  powerPin is General IO
*/#define ADC_PIN   A0#define POWER_PIN 10
DFRobot_MICS_ADC mics(/*adcPin*/ADC_PIN, /*powerPin*/POWER_PIN);
void setup() {
  Serial.begin(115200);
  while(!Serial);
  while(!mics.begin()){
    Serial.println("NO Deivces !");
    delay(1000);
  } Serial.println("Device connected successfully !");

  /**!
    Gets the power mode of the sensor
    The sensor is in sleep mode when power is on,so it needs to wake up the sensor. 
    The data obtained in sleep mode is wrong
   */
  uint8_t mode = mics.getPowerState();
  if(mode == SLEEP_MODE){
    mics.wakeUpMode();
    Serial.println("wake up sensor success!");
  }else{
    Serial.println("The sensor is wake up mode");
  }

  /**!
     Do not touch the sensor probe when preheating the sensor.
     Place the sensor in clean air.
     The default calibration time is 3 minutes.
  */
  while(!mics.warmUpTime(CALIBRATION_TIME)){
    Serial.println("Please wait until the warm-up time is over!");
    delay(1000);
  }}
void loop() {
  /**!
    Type of detection gas
    MICS-4514 You can get all gas state
    MICS-5524 You can get the state of CO, CH4, C2H5OH, C3H8, C4H10, H2, H2S, NH3
    MICS-2714 You can get the state of NO2, H2 ,NO
      CO       = 0x01  (Carbon Monoxide)
      CH4      = 0x02  (Methane)
      C2H5OH   = 0x03  (Ethanol)
      C3H8     = 0x04  (Propane)
      C4H10    = 0x05  (Iso Butane)
      H2       = 0x06  (Hydrogen)
      H2S      = 0x07  (Hydrothion)
      NH3      = 0x08  (Ammonia)
      NO       = 0x09  (Nitric Oxide)
      NO2      = 0x0A  (Nitrogen Dioxide)
  */
  int8_t gasFlag = mics.getGasExist(CH4);
  if(gasFlag == EXIST){
    Serial.println("The gas exists!");
  }else{
    Serial.println("The gas does not exist!");
  }
  delay(1000);
  //mics.sleepMode();}

Result

Open the serial port monitor and warm up for about 3 minutes, you can detect methane (CH4) leakage in real time.

Notes：

Sample 3 - Obtain Sensor Analog Value

If you want to obtain the original sensor data, calculate the gas concentration or add your own temperature compensation functions, you can download the sample program to the Arduino UNO, open serial port monitor to view the original voltage output of the MEMS chip MiCS-5524.

Steps

 /*!
  * @file  getADCData.ino
  * @brief Reading MICS sensor ADC original value
  * @n When using IIC device, select I2C address, set the dialing switch A0, A1 (Address_0 is [0 0]), (Address_1 is [1 0]), (Address_2 is [0 1]), (Address_3 is [1 1]).
  * @n When using the Breakout version, connect the adcPin and PowerPin
  * @copyright   Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
  * @licence     The MIT License (MIT)
  * @author      ZhixinLiu(zhixin.liu@dfrobot.com)
  * @version     V1.1
  * @date        2021-04-19
  * @get         from https://www.dfrobot.com
  * @url         https://github.com/dfrobot/DFRobot_MICS
  */
#include "DFRobot_MICS.h"
// When using the Breakout version, use the following program to construct an object from DFRobot_MICS_ADC/**!
  adcPin is A0~A5
  powerPin is General IO
*/#define ADC_PIN   A0#define POWER_PIN 10
DFRobot_MICS_ADC mics(/*adcPin*/ADC_PIN, /*powerPin*/POWER_PIN);
void setup() {
  Serial.begin(115200);
  while(!Serial);
  while(!mics.begin()){
    Serial.println("NO Deivces !");
    delay(1000);
  } Serial.println("Device connected successfully !");

  /**!
    Gets the power mode of the sensor
    The sensor is in sleep mode when power is on,so it needs to wake up the sensor. 
    The data obtained in sleep mode is wrong
   */
  uint8_t mode = mics.getPowerState();
  if(mode == SLEEP_MODE){
    mics.wakeUpMode();
    Serial.println("wake up sensor success!");
  }else{
    Serial.println("The sensor is wake up mode");
  }}
void loop() {
  int16_t ox_data  = 0;
  int16_t red_data = 0;
  /**!
    MICS-5524 Only OX_MODE ADC data can be obtained
    MICS-2714 Only RED_MODE ADC data can be obtained
    MICS-4514 Gravity can obtain AllMode ADC data
  */
  ox_data  = mics.getADCData(OX_MODE);
  //red_data = mics.getADCData(RED_MODE);
  Serial.print("ox  data = ");
  Serial.println(ox_data);
  //Serial.print("red data = ");
  //Serial.println(red_data);
  delay(1000);}

Results

Open the serial port monitor and warm up for about 3 minutes, you can obtain the MiCS-5524 raw data of MEMS chip.

Notes：

Precautions for use

Sensor Data Curve

The MiCS-5524 contains a CO detection unit for detecting the gas concentration data or gas presence of CO, CH4, C2H5OH, C3H8, C4H10, H2, H2S and NH3, with the reference curve as shown in the figure below.

image-20210526151930409

FAQ

For any questions, advice or cool ideas to share, please visit the DFRobot Forum.

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