Library Description

The library covers all the necessary functions to control Air quality Click board.
Air quality click communicates with the target board via analog ( AN ) pin. 
This library contains drivers for read ADC value of MQ-135 sensor.

Key functions:

• float airquality_getCorrectionFactor(float temperature, float humidity) - Get the correction factor function.
• float airquality_getResistance(uint32_t adcValue) - Get the resistance of the sensor function.
• float airquality_getCorrectedResistance(float temperature, float humidity, uint32_t adcValue) - Get the corrected resistance of the sensor function.

Examples description

The application is composed of the three sections :

• System Initialization - Initializes GPIO and LOG structures, sets AN pin as input.
• Application Initialization - Initialization driver enables GPIO and ADC, also starts write log.
• Application Task - (code snippet) This is a example which demonstrates the use of Air quality Click board. Air quality Click reads ADC value.
  Results are being sent to the Usart Terminal where you can track their changes.
  All data logs on usb uart changes for every 1 sec.

void applicationTask()
{      
    valueADC = airquality_readADC(); 
    Delay_100ms(); 
    
    IntToStr( valueADC, logText );
    mikrobus_logWrite( " ADC value: ", _LOG_TEXT );
    mikrobus_logWrite( logText, _LOG_LINE );
    mikrobus_logWrite( "-------------------", _LOG_LINE );
    Delay_1sec();
}

Additional Functions :

• void airquality_adcInit() - Function ADC initialization.
• uint32_t airquality_readADC() - Function read ADC value.
   

Other mikroE Libraries used in the example:

• ADC
• UART
• Conversions

Additional notes and information

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. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.