Intermediate
30 min
0

Say hello to clean air with ZMOD4510 and ATmega6450

Guardians of Freshness: Our solution, your healthier reality

Air quality 8 Click with UNI-DS v8

Published Aug 30, 2023

Click board™

Air quality 8 Click

Development board

UNI-DS v8

Compiler

NECTO Studio

MCU

ATmega6450

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-DS v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports a wide range of microcontrollers, such as different STM32, Kinetis, TIVA, CEC, MSP, PIC, dsPIC, PIC32, and AVR MCUs regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer over WiFi. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, UNI-DS v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the UNI-DS v8 development board contains the components necessary for the most efficient operation of the same board. An advanced integrated CODEGRIP programmer/debugger module offers many valuable programming/debugging options, including support for JTAG, SWD, and SWO Trace (Single Wire Output)), and seamless integration with the Mikroe software environment. Besides, it also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector. Communication options such as USB-UART, USB

HOST/DEVICE, CAN (on the MCU card, if supported), and Ethernet is also included. In addition, it also has the well-established mikroBUS™ standard, a standardized socket for the MCU card (SiBRAIN standard), and two display options for the TFT board line of products and character-based LCD. UNI-DS v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

UNI-DS v8 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Type

8th Generation

Architecture

AVR

MCU Memory (KB)

64

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

4096

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Reset
PG0
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
PD1
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PE4
SCL
I2C Data
PE5
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

Air quality 8 Click Schematic schematic

Step by step

Project assembly

Fusion for PIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the UNI-DS v8 as your development board.

Fusion for PIC v8 front image hardware assembly
Buck 22 Click front image hardware assembly
SiBRAIN for PIC32MZ1024EFK144 front image hardware assembly
v8 SiBRAIN MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART 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

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