Grove - Multichannel Gas Sensor


Grove – Multichannel Gas sensor is a environment detecting sensor with a built in MiCS-6814 which can detect many unhealthful gases, and three gases can be measured simultaneously due to its multi channels, so it can help you to monitor the concentration which more than one gas.

This sensor belongs to Grove system, and you can plug it onto the Base shield and work with Arduino directly without any jumper wires. The interface of it is I2C, so plug it onto the I2C port of Base shield, then you can start to work it.

The sensor value only reflects the approximated trend of gas concentration in a permissible error range, it DOES NOT represent the exact gas concentration. The detection of certain components in the air usually requires a more precise and costly instrument, which cannot be done with a single gas sensor. If your project is aimed at obtaining the gas concentration at a very precise level, then we do not recommend this gas sensor.

Before usage
Related Reading

We suggest you to read those knowledge before using the Gas sensor, it’ll help you to learn more about Arduino and our products, and also it’ll let you to use open souse hardware more easier.

After reading that you will know how to use Base shield with Grove products to work well with Arduino. Let’s start it !

To be prepared
This tutorial will include some necessary products:

  • Arduino UNO R3 or Seeeduino v4
  • Base Shield
  • Grove - Multichannel Gas Sensor

Hardware Overview


Four pins are pointed out from the figure above

Pin Label Description
GND Connect to ground
VCC Power supply: 3.3V - 5V
SDA I2C data
SCL I2C clock

The power supply is between 3.3V and 5V, so this sensor can be compatible with a micro-controller whose output voltage is 3.3V.


  • Three fully independent sensing elements on one package
  • Built with ATmega168PA
  • I2C interface with programmable address
  • Heating power can be shut down for low power
  • Detectable gases
    Carbon monoxide CO 1 – 1000ppm
    Nitrogen dioxide NO2 0.05 – 10ppm
    Ethanol C2H6OH 10 – 500ppm
    Hydrogen H2 1 – 1000ppm
    Ammonia NH3 1 – 500ppm
    Methane CH4 >1000ppm
    Propane C3H8 >1000ppm
    Iso-butane C4H10 >1000ppm

Block Diagram


Platforms Supported

Raspberry Pi
LinkIt ONE

The platforms mentioned above as supported is/are an indication of the module's hardware or theoritical compatibility. We only provide software library or code examples for Arduino platform in most cases. It is not possible to provide software library / demo code for all possible MCU platforms. Hence, users have to write their own software library.

Electrical Characteristics

Item Condition Min. Typ. Max. Unit
Voltage - 3.1 3.3 5.25 V
Ripple @Max Power - 80 100 mV
Heating Power - - - 88 mW
Max Power - - - 150 mW
ADC Precision - - 10 - Bits
I2C Rate - - 100 400 kHz
VIL @I2C -0.5 - 0.99 V
VIH @I2C 2.31 - 5.25 V

Performance RED sensor

Characteristic RED sensor Symbol Typ Min Max Unit
Sensing resistance in air R0 - 100 1500
Typical CO detection range FS - 1 1000 ppm
Sensitivity factor SR - 1.2 50 -


Performance OX sensor

Characteristic OX sensor Symbol Typ Min Max Unit
Sensing resistance in air R0 - 0.8 20
Typical NO2 detection range FS - 0.05 10 ppm
Sensitivity factor SR - 2 - -


Performance NH3 sensor

Characteristic NH3 sensor Symbol Typ Min Max Unit
Sensing resistance in air R0 - 10 1500
Typical NH3 detection range FS - 1 300 ppm
Sensitivity factor SR - 1.5 15 -


Getting Started

Hardware Installation:
1.Connect Grove - Multichannel Gas Sensor to Seeeduino.


Upload Code:
2.Download Arduino Library & Grove/Xadow firmware and install it to Arduino Library.
3.Open the code directly by the path:File -> Example -> Mutichannel_Gas_Sensor-> ReadSensorValue_Grove.

The code of ReadSensorValue_Grove is given below.

// Read Data from Grove - Multichannel Gas Sensor
#include <Wire.h>
#include "MutichannelGasSensor.h"

void setup()
    Serial.begin(115200);  // start serial for output
    Serial.println("power on!");
    gas.begin(0x04);//the default I2C address of the slave is 0x04
    Serial.print("Firmware Version = ");

void loop()
    float c;

    c = gas.measure_NH3();
    Serial.print("The concentration of NH3 is ");
    if(c>=0) Serial.print(c);
    else Serial.print("invalid");
    Serial.println(" ppm");

    c = gas.measure_CO();
    Serial.print("The concentration of CO is ");
    if(c>=0) Serial.print(c);
    else Serial.print("invalid");
    Serial.println(" ppm");

    c = gas.measure_NO2();
    Serial.print("The concentration of NO2 is ");
    if(c>=0) Serial.print(c);
    else Serial.print("invalid");
    Serial.println(" ppm");

    c = gas.measure_C3H8();
    Serial.print("The concentration of C3H8 is ");
    if(c>=0) Serial.print(c);
    else Serial.print("invalid");
    Serial.println(" ppm");

    c = gas.measure_C4H10();
    Serial.print("The concentration of C4H10 is ");
    if(c>=0) Serial.print(c);
    else Serial.print("invalid");
    Serial.println(" ppm");

    c = gas.measure_CH4();
    Serial.print("The concentration of CH4 is ");
    if(c>=0) Serial.print(c);
    else Serial.print("invalid");
    Serial.println(" ppm");

    c = gas.measure_H2();
    Serial.print("The concentration of H2 is ");
    if(c>=0) Serial.print(c);
    else Serial.print("invalid");
    Serial.println(" ppm");

    c = gas.measure_C2H5OH();
    Serial.print("The concentration of C2H5OH is ");
    if(c>=0) Serial.print(c);
    else Serial.print("invalid");
    Serial.println(" ppm");


4.Upload the code. Remember to select Seeeduino Uno from the Tools | Board menu of the Arduino environment, and select the correct serial port Arduino is using.

By opening the serial monitor, you can see the raw data read from sensor.

Update Firmware

This grove module has an ATmega168 MCU which is flashed with a factory firmware. The version had been updated to V2 at Nov11/2016. Upload below code to detect the versin of your sensor.

// Get firmware version of Grove Multichannel Gas Sensor
#include <Wire.h>
#include "MutichannelGasSensor.h"

#define SENSOR_ADDR     0X04        // default to 0x04

void setup()

    unsigned char version = gas.getVersion();
    Serial.print("Version = ");

void loop()
    // nothing to do

If the version of your sensor is V1, we advise you to upgrade it to V2 to get a better performance.

To update the firmware, you need,

  • An Arduino UNO/Seeeduino V3/
  • 6 dupont wire
  • Soldering Iron

There’s a ICSP pad on the back of the board, you need connect those pads to an Arduino board.

Sensor Arduino


Then open the example UpdateFrimware to your Arduino, open Serial monitor and you will get some info printed. Input a ‘g’ to start.


If you always get an unauthentic value, please try to calibrate the sensor. Open the example calibration and upload to your Arduino, open Serial monitor to get info when it’s calibrating.

The calibration has been done before the modules leave the factory. If you want to recalibrate, please do make sure that the air condition is fresh. And the calibration may need munutes to half an hour.


Mrunali Bawankar

Mrunali Bawankar