dht222

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DHT22 2 Click

DHT22 2 Click demo application is developed using the NECTO Studio, ensuring compatibility with mikroSDK's open-source libraries and tools. Designed for plug-and-play implementation and testing, the demo is fully compatible with all development, starter, and mikromedia boards featuring a mikroBUS™ socket.

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Click Library

• Author : MikroE Team
• Date : maj 2020.
• Type : I2C type

Software Support

Example Description

This example demonstrates the use of DHT22 2 Click board by reading the temperature and humidity data.

Example Libraries

• MikroSDK.Board
• MikroSDK.Log
• Click.Dht222

Example Key Functions

• dht222_cfg_setup Config Object Initialization function.

void dht222_cfg_setup ( dht222_cfg_t *cfg ); 

• dht222_init Initialization function.

err_t dht222_init ( dht222_t *ctx, dht222_cfg_t *cfg );

• dht222_read_reg This function reads data from the desired register.

err_t dht222_read_reg ( dht222_t *ctx, uint8_t address, uint8_t *data_out, uint8_t len );

• dht222_write_reg This function writes data to the desired register.

err_t dht222_write_reg ( dht222_t *ctx, uint8_t address, uint8_t *data_in, uint8_t len );

• dht222_get_temp_hum The function reads the temperature and humidity data from the sensor AM2322 on the DHT22 2 Click.

err_t dht222_get_temp_hum ( dht222_t *ctx, uint16_t *temperature, uint16_t *humidity );

Application Init

Initializes the driver and logger.

void application_init ( void )
{
    log_cfg_t log_cfg;
    dht222_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_info( &logger, "---- Application Init ----" );

    //  Click initialization.
    dht222_cfg_setup( &cfg );
    DHT222_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    dht222_init( &dht222, &cfg );
    Delay_ms ( 500 );
}

Application Task

Reads the temperature (degrees C) and the relative humidity (%RH) data and displays the results on the USB UART approximately once per second.

void application_task ( void )
{
    uint16_t temperature = 0;
    uint16_t humidity = 0;
    if ( DHT222_OK == dht222_get_temp_hum ( &dht222, &temperature, &humidity ) )
    {
        log_printf( &logger, " Humidity   : %.1f %%\r\n", ( float ) humidity / 10 );
        log_printf( &logger, " Temperature: %.1f C \r\n", ( float ) temperature / 10 );
        log_printf( &logger, "---------------------\r\n" );
        Delay_ms ( 1000 );
    }
}

Application Output

This Click board can be interfaced and monitored in two ways:

• Application Output - Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.
• UART Terminal - Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.

Additional Notes and Information

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.

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