Grove - Multichannel Gas Sensor

Introduction

3.3V 5.0V I2C

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.

Caution

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

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:

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.

Features

  • 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

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

Warning

Then sensor need to preheat at least 10 minutes before getting a stable data.

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
    gas.powerOn();
    Serial.print("Firmware Version = ");
    Serial.println(gas.getVersion());
}

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");

    delay(1000);
}

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.

Tip

More details about Grove modules please refer to Grove System

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()
{
    Serial.begin(115200);
    gas.begin(SENSOR_ADDR);

    unsigned char version = gas.getVersion();
    Serial.print("Version = ");
    Serial.println(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
MISO D12
SCK D13
NRST D10
GND GND
MOSI D11
VCC 5V

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

calibration

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.

Note

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.

Resources

FAQ

  • Q1. How to change I2C address of the module

    • A1. Open the I2C_Address example and run it.
  • Q2. I change the I2C address and unlucky that I forget what is it.

    • A2. Don’t worry about it, run factory_setting example to make it default. Please note that the calibration data will factory setting as well.

Tip

If you need futhur support, please feel free to contact techsupport@seeed.cc


ArduinoWioBeagleBoneRaspberry PiLinkIt ONE

Caution

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.

Techsupport

For any technical issue, you are most welcome to contact techsupport@seeed.cc, our techsupport engineers will help you. Thank you!

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