Headphone AMP 2 Click

Headphone AMP 2 Click is a compact add-on board that contains a stereo headphone amplifier. This board features the MAX9723, a stereo DirectDrive headphone amplifier with BassMax, volume control, and I2C from Analog Devices. The amplifier delivers 62mW into a 16Ω load, and features a high 90dB PSRR at 1KHz and a low 0.006% THD+N. It also features an integrated 32-level volume control, Click-and-pop suppression, ±8kV HBM ESD-protected headphone outputs, short-circuit and thermal-overload protection, and more.

Click Product page

Click library

• Author : Nenad Filipovic
• Date : Jun 2023.
• Type : I2C type

Software Support

We provide a library for the Headphone AMP 2 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 Headphone AMP 2 Click driver.

Standard key functions :

• headphoneamp2_cfg_setup Config Object Initialization function.

  void headphoneamp2_cfg_setup ( headphoneamp2_cfg_t *cfg );

• headphoneamp2_init Initialization function.

  err_t headphoneamp2_init ( headphoneamp2_t *ctx, headphoneamp2_cfg_t *cfg );

• headphoneamp2_default_cfg Click Default Configuration function.

  err_t headphoneamp2_default_cfg ( headphoneamp2_t *ctx );

Example key functions :

• headphoneamp2_set_command Headphone AMP 2 set the command function.

  err_t headphoneamp2_set_command ( headphoneamp2_t *ctx, headphoneamp2_cmd_t cmd_ctrl );

• headphoneamp2_enable Headphone AMP 2 enable the device function.

  void headphoneamp2_enable ( headphoneamp2_t *ctx );

• headphoneamp2_disable Headphone AMP 2 disable the device function.

  void headphoneamp2_disable ( headphoneamp2_t *ctx );

Example Description

This example demonstrates the use of the Headphone AMP 2 Click board™, the headphone amplifier with BassMax and volume control.

The demo application is composed of two sections :

Application Init

The initialization of I2C module and log UART. After driver initialization, the app sets the default configuration.

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    headphoneamp2_cfg_t headphoneamp2_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.
    headphoneamp2_cfg_setup( &headphoneamp2_cfg );
    HEADPHONEAMP2_MAP_MIKROBUS( headphoneamp2_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == headphoneamp2_init( &headphoneamp2, &headphoneamp2_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    if ( HEADPHONEAMP2_ERROR == headphoneamp2_default_cfg ( &headphoneamp2 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

    log_info( &logger, " Application Task " );
    log_printf( &logger, "-------------------------\r\n" );
    Delay_ms ( 100 );
}

Application Task

This example demonstrates the use of the Headphone AMP 2 Click board™. The application wakes up the device, enables BassMax and Maximum Gain modes, and switches the sound volume from level 1 to the max level. Results are being sent to the UART Terminal, where you can track their changes.

void application_task ( void ) 
{
    static headphoneamp2_cmd_t cmd_ctrl;
    cmd_ctrl.wakes_up = HEADPHONEAMP2_CMD_ENABLE;
    cmd_ctrl.bass_max = HEADPHONEAMP2_CMD_ENABLE;
    cmd_ctrl.gain_max = HEADPHONEAMP2_CMD_ENABLE;
    cmd_ctrl.volume   = HEADPHONEAMP2_VOL_MUTE;

    log_printf( &logger, " Volume : " );
    for ( uint8_t volume = HEADPHONEAMP2_VOL_LVL_1; volume <= HEADPHONEAMP2_VOL_LVL_MAX; volume++ )
    {
        cmd_ctrl.volume = volume;
        if ( HEADPHONEAMP2_OK == headphoneamp2_set_command( &headphoneamp2, cmd_ctrl ) )
        {
            log_printf( &logger, "|" );
        }
        Delay_ms ( 1000 );
    }
    log_printf( &logger, "\r\n-------------------------\r\n" );
}

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.HeadphoneAMP2

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.