Intermediate
30 min
0

Say hello to clean air with ZMOD4510 and STM32F412RE

Guardians of Freshness: Our solution, your healthier reality

Air quality 8 Click with UNI Clicker

Published Aug 30, 2023

Click board™

Air quality 8 Click

Development board

UNI Clicker

Compiler

NECTO Studio

MCU

STM32F412RE

Designed to address the growing concern of air pollution, our monitor solution acts as a guardian, ensuring the air you breathe is of the highest quality

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Hardware Overview

How does it work?

Air quality 8 Click is based on the ZMOD4510, a pre-calibrated digital sensor designed for reliable indoor and outdoor air quality detection from Renesas. This sensor comes with selective ozone measurement capabilities (NO2 and O3) and allows improved energy efficiency with less than 23mW of power consumption in continuous operation without compromising air quality. It also features electrical and gas calibration, proven MOx material, a digital interface, siloxane resistance, high sensitivity, and long-term stability, allowing ppb detection limits. It covers extended operating humidity and temperature ranges from 5 to 90%RH and from -20°C to 50°C with ozone and nitrogen dioxide measurement ranges from 20 to 500ppb. The ZMOD4510 has a gas-sense element consisting of a heater element on a silicon-based MEMS structure, a metal-oxide (MOx) chemiresistor, and a CMOS signal conditioning IC that controls the sensor temperature and

measures the MOx resistance, which is a function of the gas concentration. It has two operational modes. The first mode of operation allows a general measurement of Air Quality, including the non-selective measurement of nitrogen dioxide (NO2) and ozone (O3). The second mode of operation allows the selective measurement of ozone (O3) featuring Ultra-Low Power with an average consumption of 0.2mW during its fast sample rate of 2 seconds. It detects typical gases based on studies and international standards for outdoor air quality and uses a sequence of applied temperatures to sample the air and report an Air Quality Index (AQI). The sensor does not require an active or direct airflow onto the sensor module because diffusion of ambient gas does not limit the sensor response time. The ZMOD4510 can also detect safety-relevant gases; however, the sensor module is not designed to detect these interferants reliably. Therefore, it is not approved

for use in safety-critical or life-protecting applications. Air quality 8 Click communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting Standard Mode operation with a clock frequency of 100kHz and Fast Mode up to 400kHz. In addition, it also possesses other features such as a reset pin routed to the RST pin on the mikroBUS™ socket, which with a low logic level puts the module into a Reset state, an additional interrupt signal routed on the INT pin of the mikroBUS™ socket labeled as INT, indicating the status of measurement process itself. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Air quality 8 Click top side image
Air quality 8 Click bottom side 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)

512

Silicon Vendor

STMicroelectronics

Pin count

64

RAM (Bytes)

262144

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Reset
PC13
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
Interrupt
PB13
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PB6
SCL
I2C Data
PB7
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

Air quality 8 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 Air Quality 8 Click driver.

Key functions:

  • airquality8_calc_oaq - Air Quality 8 calculates AQI function

  • airquality8_read_rmox - Air Quality 8 calculate rmox resistance function

  • airquality8_start_measurement - Air Quality 8 start measurement 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 AirQuality8 Click example
 *
 * # Description
 * This library contains API for Air Quality 8 Click driver.
 * The library initializes and defines the I2C bus drivers 
 * to write and read data from registers. 
 * The library also includes a function for configuring sensor and measurement, 
 * read and calculate mox resistance ( RMOX ) and air quality index ( AQI ), etc.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of I2C module and log UART, and additional pins.
 * After the driver inits and executes a default configuration, 
 * the app read product ID and configuration parameters, 
 * initializes the sensor and measurement.
 *
 * ## Application Task
 * This is an example that demonstrates the use of the Air Quality 8 Click board™.
 * In this example, the app performs the start of the measurement,
 * reads an array of the 15 mox resistances measurements ( RMOX ), 
 * and calculates the air quality index ( AQI ), the app also, displays if an error occurs.
 * Results are being sent to the Usart Terminal where you can track their changes.
 *
 * ## Additional Function
 * - static void display_error ( void )
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "airquality8.h"

static airquality8_t airquality8;
static log_t logger;
static uint16_t mox_lr;
static uint16_t mox_er;
static uint8_t status_flag;

static void display_error ( void )
{
    if ( status_flag == AIRQUALITY8_ERROR_INIT_OUT_OF_RANGE )
    {
        log_printf( &logger, " The initialize value is out of range.\r\n" );
    }
    
    if ( status_flag == AIRQUALITY8_ERROR_GAS_TIMEOUT )
    {
        log_printf( &logger, " The operation took too long.\r\n" );
    }
    
    if ( status_flag == AIRQUALITY8_ERROR_I2C )
    {
        log_printf( &logger, " Failure in i2c communication.\r\n" );
    }
    
    if ( status_flag == AIRQUALITY8_ERROR_SENSOR_UNSUPPORTED )
    {
        log_printf( &logger, " Sensor is not supported with this firmware.\r\n" );
    }
    
    if ( status_flag == AIRQUALITY8_ERROR_CONFIG_MISSING )
    {
        log_printf( &logger, " There is no pointer to a valid configuration.\r\n" );
    }
    
    if ( status_flag == AIRQUALITY8_ERROR_SENSOR )
    {
        log_printf( &logger, " Sensor malfunction.\r\n" );
    }
}

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    airquality8_cfg_t airquality8_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.
    airquality8_cfg_setup( &airquality8_cfg );
    AIRQUALITY8_MAP_MIKROBUS( airquality8_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == airquality8_init( &airquality8, &airquality8_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( AIRQUALITY8_ERROR == airquality8_default_cfg ( &airquality8 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    Delay_ms( 100 );
    
    static uint8_t cfg_data[ 6 ];
    static uint8_t prod_data[ 5 ];
    static uint16_t pid;
    
    airquality8_get_sensor_info( &airquality8, &cfg_data[ 0 ], &prod_data[ 0 ], &pid );
    
    if ( pid != AIRQUALITY8_PRODUCT_ID )
    {
        status_flag = AIRQUALITY8_ERROR_I2C;
        display_error( );
        for ( ; ; );
    }
    Delay_ms( 100 );
    
    log_printf( &logger, "---------------------------\r\n" );
    log_printf( &logger, " Product ID : 0x%.2X  \r\n", pid );
    Delay_ms( 100 );
    
    airquality8_init_sensor( &airquality8, &mox_lr, &mox_er );
    Delay_ms( 10 );
    
    airquality8_init_measurement( &airquality8 );
    Delay_ms( 10 );
    
    log_printf( &logger, "---------------------------\r\n" );
    log_info( &logger, " Application Task " );
    log_printf( &logger, "---------------------------\r\n" );
    log_printf( &logger, "      Air Quality Index\r\n" );
    log_printf( &logger, "- - - - - - - - - - - - - -\r\n" );
    Delay_ms( 100 );
}

void application_task ( void ) 
{   
    static uint8_t status_data;
    static float rmox;
    static float rmox_seq[ 15 ];
    static float aqi;
    
    status_flag = airquality8_start_measurement( &airquality8 );

    airquality8_get_status( &airquality8, &status_data );
    Delay_ms( 10 );
    
    while ( ( status_data & AIRQUALITY8_STATUS_LAST_SEQ_STEP_MASK ) != AIRQUALITY8_OK )
    {
        airquality8_get_status( &airquality8, &status_data );
        Delay_ms( 10 );
    }

    for ( uint8_t n_cnt = 0; n_cnt < 15; n_cnt++ )
    {        
        status_flag = airquality8_read_rmox( &airquality8, &rmox, mox_lr, mox_er );
        rmox_seq[ n_cnt ] = rmox;
        Delay_ms( 100 ); 
        
        if ( status_flag != AIRQUALITY8_OK )
        {
            display_error( );
        }
    }       
    
    aqi = airquality8_calc_oaq( rmox_seq, AIRQUALITY8_RCDA_STRATEGY_ADJ, AIRQUALITY8_GAS_DETECTION_STRATEGY_AUTO );
    log_printf( &logger, " \tAQI : %.3f \r\n", aqi );
    log_printf( &logger, "---------------------------\r\n" );
    Delay_ms( 1000 );
}

void main ( void ) 
{
    application_init( );

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

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

Additional Support

Resources