Air quality 2 Click

How does it work?

Air Quality 2 Click is based on the iAQ-Core, an indoor air quality sensor module from Scio Sense. It uses MEMS metal oxide sensing technology and can be used in a 5 to 95% relative humidity range. The sensor itself is protected by a plastic cap and a filter membrane, which shouldn’t be removed. The first functional reading after start-up appears after 5 minutes. The sensor has Automatic Baseline Correctio (ABC), meaning you don’t need to do further calibration.

The term CO2 equivalent, or CO2e, represents a unit of measurement for the amount of carbon dioxide gas present in some “greenhouse gases”. The “greenhouse gas” is any gas in the atmosphere that absorbs and re-emits heat, thus making a planet warmer than it otherwise would be. Volatile organic compounds (VOC) are organic chemicals with very high vapor pressure at room temperature, and some can harm human health. These chemicals are carbon-based (formaldehyde, toluene, benzene, and more) and are called “volatile” because they become gases at room temperature. They are emitted from various products, like hairspray, household cleaning products, paint, or air freshener, that we use daily.

Air Quality 2 Click uses a standard 2-Wire I2C interface to communicate with the host MCU, supporting clock speeds up to 100KHz. As the sensor is a 3.3V-only device, this Click board™ features the PCA9306, a dual bidirectional I2C Bus and SMBus voltage level translator from Texas Instruments.

This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the PWR SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

Specifications

Pinout diagram

This table shows how the pinout on Air quality 2 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	NC
	NC	2	RST	INT	15	NC
	NC	3	CS	TX	14	NC
	NC	4	SCK	RX	13	NC
	NC	5	MISO	SCL	12	SCL	I2C clock
	NC	6	MOSI	SDA	11	SDA	I2C data
Power supply	3.3V	7	3.3V	5V	10	5V	Power supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Air quality 2 Click electrical specifications

Software Support

We provide a library for the Air quality 2 Click as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Air quality 2 Click driver.

Key functions

• This function reads data.

• Reads all data information about the indoor air quality.

Example Description

This app measure indoor air quality.

 void application_task ( void ) 
 { 
     uint8_t status_info; 
     uint16_t value_co2; 
     uint16_t value_tvoc; 
     int32_t resistance; 

     status_info = airquality2_get_all_data( &airquality2, &value_co2, &value_tvoc, &resistance ); 
     Delay_100ms( ); 

     if ( status_info == AIRQUALITY2_STATUS_OK ) 
     { 
         log_printf( &logger, "       | Status : OK     |rn" ); 
     } 
     if ( status_info == AIRQUALITY2_STATUS_BUSY ) 
     { 
         log_printf( &logger, "       | Status : BUSY   |rn" ); 
     } 
     if ( status_info == AIRQUALITY2_STATUS_ERROR ) 
     { 
         log_printf( &logger, "       | Status : ERROR  |rn" ); 
     } 
     if ( status_info == AIRQUALITY2_STATUS_RUNIN ) 
     { 
         log_printf( &logger, "       | Status : RUNIN  |rn" ); 
     } 

     log_printf( &logger, "----------------------------------rn" ); 

     log_printf( &logger, " CO2        : %u [ ppm ] rn", value_co2 ); 

     log_printf( &logger, " TVOC       : %u [ ppb ] rn", value_tvoc ); 

     log_printf( &logger, " Resistance : %ld [ Ohm ] rn", resistance ); 

     log_printf( &logger, "----------------------------------rn" ); 

     Delay_1sec( ); 
     Delay_1sec( ); 
     Delay_1sec( ); 
     Delay_1sec( ); 
     Delay_1sec( ); 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Airquality2

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MIKROE Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.