Library Description

The library performs a audio control and works as audio amplifier. Possible commands are to turn ON or OFF the output (speaker) and to set the output volume by selecting the desired channel. For more details check documentation.

Key functions:

• T_AUDIOAMP4_RETVAL audioamp4_setChannel( uint8_t channel ) - Function performs a volume channel selection.
• T_AUDIOAMP4_RETVAL audioamp4_shutdown( uint8_t state ) - Function turns shutdown to ON or OFF state.

Examples description

The application is composed of the three sections :

• System Initialization - Initializes peripherals and pins.
• Application Initialization - Initializes GPIO interface, turns shutdown OFF and performs a volume channel 3 selection.
• Application Task - (code snippet) - Checks which command is sent from uart and performs a determined command. Note : Possible commands are:
  • Shutdown OFF
  • Shutdown ON l Legend 0-7 Volume channel selection

void applicationTask()
{
    rxDat = UART_Rdy_Ptr();

    if (rxDat != _NO_RECEIVED_DATA)
    {
        rxDat = UART_Rd_Ptr();

        if (rxDat == '+')
        {
            audioamp4_shutdown( _AUDIOAMP4_SHUTDOWN_OFF );

            mikrobus_logWrite( "* Shutdown OFF *", _LOG_LINE );
        }
        else if (rxDat == '-')
        {
            audioamp4_shutdown( _AUDIOAMP4_SHUTDOWN_ON );

            mikrobus_logWrite( "* Shutdown ON *", _LOG_LINE );
        }
        else if (rxDat == 'l')
        {
            writeLegend();
        }
        else
        {
            channSel = rxDat - '0';
            responseCheck = audioamp4_setChannel( channSel );

            checkResponse();
        }
    }
}

Additional Functions :

• void checkResponse() - Checks is channel selection parametar valid or not.
• void writeLegend() - Writes the all possible commands on uart.

Other mikroE Libraries used in the example:

• UART

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 clickor 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.