VU Meter 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.

• Author : Stefan Filipovic
• Date : Sep 2021.
• Type : SPI type

This example demonstrates the use of VU Meter Click board.

• MikroSDK.Board
• MikroSDK.Log
• Click.VUMeter

• vumeter_cfg_setup Config Object Initialization function.

void vumeter_cfg_setup ( vumeter_cfg_t *cfg );

• vumeter_init Initialization function.

err_t vumeter_init ( vumeter_t *ctx, vumeter_cfg_t *cfg );

• vumeter_read_an_pin_voltage This function reads results of AD conversion of the AN pin and converts them to proportional voltage level.

err_t vumeter_read_an_pin_voltage ( vumeter_t *ctx, float *data_out );

• vumeter_set_gain_level This function sets the input signal gain level (the microphone sensitivity).

err_t vumeter_set_gain_level ( vumeter_t *ctx, uint8_t gain_lvl );

• vumeter_calculate_vu_level This function calculates VU level from the analog voltage input.

float vumeter_calculate_vu_level ( vumeter_t *ctx, uint16_t sample_rate_ms );

Initializes the driver and sets the gain level (the microphone sensitivity) to maximum.

void application_init ( void )
{
    log_cfg_t log_cfg;          /**< Logger config object. */
    vumeter_cfg_t vumeter_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.

    vumeter_cfg_setup( &vumeter_cfg );
    VUMETER_MAP_MIKROBUS( vumeter_cfg, MIKROBUS_1 );
    err_t init_flag  = vumeter_init( &vumeter, &vumeter_cfg );
    if ( SPI_MASTER_ERROR == init_flag )
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    
    vumeter_set_gain_level ( &vumeter, VUMETER_GAIN_LEVEL_MAX );
    log_info( &logger, " Application Task " );
}

Calculates VU level from the analog voltage read from AN pin, and displays the results on the USB UART approximately every 100ms.

void application_task ( void )
{
    log_printf( &logger, " VU level: %.3f VU\r\n", vumeter_calculate_vu_level ( &vumeter, 100 ) );
}

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.

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.