Intermediate
30 min

Ensure the air you breathe is of the highest quality using SGP30 and MK64FN1M0VDC12

See the unseen, breathe the pure

Air quality 4 Click with Clicker 2 for Kinetis

Published Aug 29, 2023

Click board™

Air quality 4 Click

Dev. board

Clicker 2 for Kinetis

Compiler

NECTO Studio

MCU

MK64FN1M0VDC12

From homes to workplaces, our air quality monitor solution seamlessly integrates into any environment, providing real-time insights for a safer, cleaner lifestyle

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Hardware Overview

How does it work?

Air Quality 4 Click is based on the SGP30 from Sensirion, a multi-pixel gas sensor for indoor applications. This sensor is a system of several metal-oxide sensing elements on a chip (pixels), used to measure and process readings of various gasses in the air and output them in the form of two complementary air quality readings - Total Volatile Organic Compounds (TVOC) [ppb] and CO2 equivalent signal [ppm]. The traditional metal-oxide (MOX) sensors suffer from sensitivity and responsiveness degradation after siloxane exposure. Siloxanes are compounds commonly found in the air, negatively affecting the MOX sensors. To overcome this problem, the SGP30 sensors use the advanced MOXSens® Technology, which provides unmatched robustness against siloxane contamination. This results in unprecedented long-term stability and accuracy. The SGP30 uses a dynamic baseline compensation algorithm and calibration parameters to record TVOC and CO2eq properties accurately. These baseline values of the compensation algorithm

can be stored externally and read back into the device with the appropriate I2C commands and can be used in the event of power down or restart. For the first 15 seconds after the I2C initialization command, the sensor is in an initialization phase of collecting sensor measurements and baseline compensation data. When the measurement command is attempted, it will return fixed values of 400 ppm CO2eq and 0 ppb TVOC. The device also allows air humidity corrections over the results for both the compensated and raw values. However, an absolute humidity sensor should be used for obtaining the humidity reading. Readings from SHT click or similar humidity-measuring devices can be used for this purpose. The appropriate I2C command will store the value in the on-chip memory and perform the corrections accordingly. Additional components on Air Quality 4 clicks are used to provide necessary voltage levels for the SGP30 sensor IC. This sensor has a common voltage level of 1.8V, so to provide proper communication with 3.3V and 5V capable MCUs, a

small LDO voltage regulator has to be used, along with the level shifter, which provides the required logic voltage levels. The SPX3819M5, a small 500mA LDO voltage regulator, provides a power supply of 1.8V for the SGP30. The PCA9306 dual bidirectional I2C bus and SMBus voltage level shifter are used for the level shifting. This level shifter IC allows shifting (converting) the I2C signal levels to the voltage level selected by the VCC SEL onboard SMD jumper. This allows 3.3V and 5V capable MCUs to be interfaced with the Air quality 4 Click. More detailed information about all the available I2C commands can be found in the SGP30 datasheet. However, all the functions and commands necessary to perform air quality readings and functions used to calculate H2 and Ethanol concentration levels are contained within the Air Quality 4 click libraries provided with this click board™. Their usage is demonstrated in the included example application, which can be used as a reference for a custom application design.

Air quality 4 Click top side image
Air quality 4 Click bottom side image

Features overview

Development board

Clicker 2 for Kinetis is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit ARM Cortex-M4F microcontroller, the MK64FN1M0VDC12 from NXP Semiconductors, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a JTAG programmer connector, and two 26-pin headers for interfacing with external electronics. Its compact design with clear and easily recognizable silkscreen markings allows you to build gadgets with unique functionalities and

features quickly. Each part of the Clicker 2 for Kinetis development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the Clicker 2 for Kinetis programming method, using a USB HID mikroBootloader or an external mikroProg connector for Kinetis programmer, the Clicker 2 board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Micro-B cable, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or

using a Li-Polymer battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several user-configurable buttons and LED indicators. Clicker 2 for Kinetis 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.

Clicker 2 for Kinetis dimensions image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M4

MCU Memory (KB)

1024

Silicon Vendor

NXP

Pin count

121

RAM (Bytes)

262144

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PD8
SCL
I2C Data
PD9
SDA
Power Supply
5V
5V
Ground
GND
GND
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Take a closer look

Click board™ Schematic

Air quality 4 Click Schematic schematic

Step by step

Project assembly

Clicker 2 for PIC32MZ front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Clicker 2 for Kinetis as your development board.

Clicker 2 for PIC32MZ front image hardware assembly
GNSS2 Click front image hardware assembly
Prog-cut hardware assembly
Board mapper by product7 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
Flip&Click PIC32MZ MCU step 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

Software Support

Library Description

This library contains API for Air Quality 4 Click driver.

Key functions:

  • air_quality4_soft_reset - This function calls general reset witch resets all states on the chip

  • air_quality4_get_co2_and_tvoc - This function writes 2 bytes CO2 data and 2 bytes TVOC data without CRC data

  • air_quality4_get_h2_and_ehtoh - This function writes 2 bytes H2 data and 2 bytes EthOH data without CRC data

Open Source

Code example

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.

/*!
 * \file 
 * \brief AirQuality4 Click example
 * 
 * # Description
 * This application measures the amount of substances in air and air quality and logs the results.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * nitializes Click driver and gets ID data.
 * 
 * ## Application Task  
 * Performs measurements of air concentracion for H2, EthOH, CO2 and TVOC data.
 * Results of measurement shows on USBUART.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "airquality4.h"

// ------------------------------------------------------------------ VARIABLES

static airquality4_t airquality4;
static log_t logger;
static uint8_t buffer_data[ 6 ];
static uint16_t data_buffer[ 2 ];

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    airquality4_cfg_t cfg;

    /** 
     * 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.

    airquality4_cfg_setup( &cfg );
    AIRQUALITY4_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    airquality4_init( &airquality4, &cfg );
    airquality4_default_cfg( &airquality4 );
}

void application_task ( void )
{
    air_quality4_get_h2_and_ethon( &airquality4, data_buffer);

    log_printf( &logger, "H2 value is: %u\n", data_buffer[ 0 ] );
    log_printf( &logger, "EthOH value is:  %u\n", data_buffer[ 1 ] );

    air_quality4_set_baseline( &airquality4 );
    air_quality4_get_co2_and_tvoc( &airquality4, &data_buffer[ 0 ] );
    
    log_printf( &logger, "CO2 value is: %u\n", data_buffer[ 0 ] );
    log_printf( &logger, "TVOC value is: %u\n\n", data_buffer[ 1 ] );

    Delay_ms ( 1000 );
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}


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

Additional Support

Resources

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