Beginner
10 min
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Minimize the risk of methane-related accidents with MQ-4 and MK20DX128VFM5

Your shield against hazardous gases in the air

METHANE Click with UNI Clicker

Published Jun 20, 2023

Click board™

METHANE Click

Development board

UNI Clicker

Compiler

NECTO Studio

MCU

MK20DX128VFM5

Accurately identify and monitor the presence of methane gas to prevent potential hazards such as explosions, fires, and environmental damage

A

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Hardware Overview

How does it work?

Methane Click is based on the MQ-4 methane (CH4) sensor from Zhengzhou Winsen Electronics Technology, which detects methane's presence and concentration in the air. The gas sensing layer on the MQ-4 sensor unit is made of Tin dioxide (SnO2), which has lower conductivity in clean air. The conductivity increases as the levels of methane rise. It has a high sensitivity to methane in a wide range suitable for detecting it in concentrations from 200 to 10.000ppm. Besides a binary indication of the presence of methane, the

MQ-4 also provides an analog representation of its concentration in the air sent directly to an analog pin of the mikroBUS™ socket labeled OUT. The analog output voltage the sensor provides varies in proportion to the methane concentration; the higher the methane concentration in the air, the higher the output voltage. Methane Click has a small potentiometer that allows you to adjust the load resistance of the sensor circuit, to calibrate the sensor for the environment in which you'll be using it. For precise calibration, the sensor must preheat

(once powered up, it takes 24h to reach the right temperature). This Click board™ can be operated only with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

METHANE Click hardware overview image

Features overview

Development board

UNI Clicker is a compact development board designed as a complete solution that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It supports a wide range of microcontrollers, such as different ARM, PIC32, dsPIC, PIC, and AVR from various vendors like Microchip, ST, NXP, and TI (regardless of their number of pins), four mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a debugger/programmer connector, and two 26-pin headers for interfacing with external electronics. Thanks to innovative manufacturing technology, it allows you to build

gadgets with unique functionalities and features quickly. Each part of the UNI Clicker development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the UNI Clicker programming method, using a third-party programmer or CODEGRIP/mikroProg connected to onboard JTAG/SWD header, the UNI Clicker board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Type-C (USB-C) connector, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or using a Li-Po/Li

Ion battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board (plus USB HOST/DEVICE), including the well-established mikroBUS™ socket, a standardized socket for the MCU card (SiBRAIN standard), and several user-configurable buttons and LED indicators. UNI Clicker is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

UNI clicker double image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

ARM Cortex-M4

MCU Memory (KB)

160

Silicon Vendor

NXP

Pin count

32

RAM (Bytes)

16384

Used MCU Pins

mikroBUS™ mapper

Analog Output
PD5
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
NC
NC
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

METHANE Click Schematic schematic

Step by step

Project assembly

UNI Clicker front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI Clicker as your development board.

UNI Clicker front image hardware assembly
Thermo 28 Click front image hardware assembly
SiBRAIN for STM32F745VG front image hardware assembly
Prog-cut hardware assembly
UNI Clicker MB 1 - upright/with-background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for Methane Click driver.

Key functions:

  • methane_read_an_pin_value - Methane read AN pin value function.

  • methane_read_an_pin_voltage - Methane read AN pin voltage level function.

Open Source

Code example

This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.

/*!
 * @file main.c
 * @brief Methane Click Example.
 *
 * # Description
 * The demo application shows the reading of the adc 
 * values given by the sensors.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Configuring clicks and log objects.
 * 
 * ## Application Task  
 * Reads the adc value and prints in two forms adc value and voltage.
 *
 * @author Stefan Ilic
 *
 */

#include "board.h"
#include "log.h"
#include "methane.h"

static methane_t methane;   /**< Methane Click driver object. */
static log_t logger;    /**< Logger object. */

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    methane_cfg_t methane_cfg;  /**< Click config object. */

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    log_info( &logger, " Application Init " );

    // Click initialization.

    methane_cfg_setup( &methane_cfg );
    METHANE_MAP_MIKROBUS( methane_cfg, MIKROBUS_1 );
    if ( methane_init( &methane, &methane_cfg ) == ADC_ERROR ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    log_info( &logger, " Application Task " );
}

void application_task ( void ) {
    uint16_t methane_an_value = 0;

    if ( methane_read_an_pin_value ( &methane, &methane_an_value ) != ADC_ERROR ) {
        log_printf( &logger, " ADC Value : %u\r\n", methane_an_value );
    }

    float methane_an_voltage = 0;

    if ( methane_read_an_pin_voltage ( &methane, &methane_an_voltage ) != ADC_ERROR ) {
        log_printf( &logger, " AN Voltage : %.3f[V]\r\n\n", methane_an_voltage );
    }

    Delay_ms( 1000 );
}

void main ( void ) {
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}

// ------------------------------------------------------------------------ END

Additional Support

Resources