Pollution click

Pollution click carries the VOC gas sensor and has high sensitivity to organic gases such as methanal (also known as formaldehyde), benzene, alcohol, toluene, etc.

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Click library

• Author : Mihajlo Djordjevic
• Date : Dec 2019.
• Type : ADC type

Software Support

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

Package can be downloaded/installed directly form compilers IDE(recommended way), or downloaded from our LibStock, or found on mikroE github account.

Library Description

This library contains API for Pollution Click driver.

Standard key functions :

• Config Object Initialization function.

  void pollution_cfg_setup ( pollution_cfg_t *cfg );

• Initialization function.

  POLLUTION_RETVAL pollution_init ( pollution_t ctx, pollution_cfg_t cfg );

• Click Default Configuration function.

  void pollution_default_cfg ( pollution_t *ctx );

Example key functions :

• This function read ADC data.

  pollution_data_t pollution_generic_read ( pollution_t *ctx );

• This function gets load voltage from read ADC value.

  float pollution_measure_load_voltage ( pollution_t *ctx, uint16_t adc_value );

• This function gets the corrected resistance of the sensor.

  float pollution_get_corrected_resistance ( pollution_t *ctx, uint16_t adc_value );

Examples Description

Example code reads ADC value and measures quantity of organic gases in the air.

The demo application is composed of two sections :

Application Init

Application Init performs Logger and Click initialization.

void application_init ( void )
{
    log_cfg_t log_cfg;
    pollution_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_printf( &logger, "---------------------------------------------\r\n" );
    log_printf( &logger, "------------  Application  Init ------------\r\n" );
    Delay_ms ( 1000 );

    //  Click initialization.

    pollution_cfg_setup( &cfg );
    POLLUTION_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    pollution_init( &pollution, &cfg );

    log_printf( &logger, "---------------------------------------------\r\n" );
    log_printf( &logger, "-------------- Pollution Click --------------\r\n" );
    log_printf( &logger, "---------------------------------------------\r\n" );
    Delay_ms ( 1000 );

    pollution_default_cfg( &pollution );
    Delay_ms ( 1000 );

    log_printf( &logger, "------------ ADC Initializated ------------\r\n" );
    log_printf( &logger, "---------------------------------------------\r\n" );
    Delay_ms ( 1000 );
}

Application Task

This is an example which demonstrates the usage of Pollution Click board. Pollution Click reads ADC value, load voltage from ADC value, and reads
corrected resistance of the sensor where results are being sent to the UART terminal where you can track changes.

void application_task ( void )
{
    pollution_data_t tmp;

    tmp = pollution_generic_read( &pollution );
    log_printf( &logger, " ADC value : %d ppm\r\n\n", tmp );
    Delay_ms ( 1000 );

    value_volt = pollution_measure_load_voltage( &pollution, tmp );
    log_printf( &logger, " Load voltage : %0.2f V\r\n\n", value_volt );
    Delay_ms ( 1000 );

    value_res = pollution_get_corrected_resistance( &pollution, tmp );
    log_printf( &logger, " Corrected resistance : %0.2f kOhm\r\n\n", value_res );
    log_printf( &logger, "---------------------------------------------\r\n\n" );
    Delay_ms ( 1000 );
}  

The full application code, and ready to use projects can be installed directly form compilers IDE(recommneded) or found on LibStock page or mikroE GitHub accaunt.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Pollution

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