Volume 2 Click

Volume 2 Click is a compact add-on board that provides the user with complete digital volume control. This board features the NJU72341, a 2-channel I2C configurable electronic volume IC with external mute control from NJRC.

Click Product page

Click library

• Author : Stefan Nikolic
• Date : feb 2021.
• Type : I2C type

Software Support

We provide a library for the Volume2 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 from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on mikroE github account.

Library Description

This library contains API for Volume2 Click driver.

Standard key functions :

• volume2_cfg_setup Config Object Initialization function.

  void volume2_cfg_setup ( volume2_cfg_t *cfg );

• volume2_init Initialization function.

  VOLUME2_RETVAL volume2_init ( volume2_t *ctx, volume2_cfg_t *cfg );

• volume2_default_cfg Click Default Configuration function.

  void volume2_default_cfg ( volume2_t *ctx );

Example key functions :

• volume2_update_vol_data This function updates the volume by using direct defined structure options.

  err_t volume2_update_vol_data ( volume2_t *ctx, volume2_vol_data_t update_data );

• volume2_device_mute This function is used to set mute on or off by controlling the mte pin.

  err_t volume2_device_mute ( volume2_t *ctx, uint8_t mte_state );

• volume2_generic_write This function writes a desired number of data bytes starting from the selected register by using I2C serial interface.

  err_t volume2_generic_write ( volume2_t *ctx, uint8_t reg, uint8_t *tx_buf, uint8_t tx_len );

Example Description

This example shows how Volume 2 Click board can be used for controlling the audio channels. Thanks to this, a simple audio effect is created by switching volume from right to left and vice versa.

The demo application is composed of two sections :

Application Init

UART LOG and I2C drivers are initialized, following the default configuration. By default, both channels are set to 9 dB gain with zero cross detection enabled.

void application_init ( void ) {
    log_cfg_t log_cfg;          /**< Logger config object. */
    volume2_cfg_t volume2_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.

    volume2_cfg_setup( &volume2_cfg );
    VOLUME2_MAP_MIKROBUS( volume2_cfg, MIKROBUS_1 );
    err_t init_flag = volume2_init( &volume2, &volume2_cfg );
    if ( init_flag == I2C_MASTER_ERROR ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    volume2_default_cfg( &volume2 );
    Delay_ms ( 100 );
    log_info( &logger, " Application Task " );
}

Application Task

The task performs and effect of switching the volume from right to left channel and vice versa. Like playing ping-pong with the sound.

void application_task ( void ) {
    for ( rising_vol = 0 ; rising_vol < max_atten ; rising_vol++ ) {
        volume_upd_data.attenuation_ch1 = rising_vol;
        volume_upd_data.attenuation_ch2 = max_atten - rising_vol;
        volume2_update_vol_data( &volume2, volume_upd_data );
        Delay_ms ( 50 );
    }
    Delay_ms ( 1000 );
    for ( rising_vol = 0 ; rising_vol < max_atten ; rising_vol++ ) {
        volume_upd_data.attenuation_ch1 = max_atten - rising_vol;
        volume_upd_data.attenuation_ch2 = rising_vol;
        volume2_update_vol_data( &volume2, volume_upd_data );
        Delay_ms ( 50 );
    }
    Delay_ms ( 1000 );
}

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

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Volume2

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 Mikroelektronika compilers.