fm

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FM Click

FM 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 : Jan 2020.
• Type : I2C type

Software Support

Example Description

This Click represent FM radio tuner which supports worldwide FM band (76 – 108 MHz) and has a set of features such as automatic frequency and gain control, seek tuning and volume control.

Example Libraries

• MikroSDK.Board
• MikroSDK.Log
• Click.Fm

Example Key Functions

• fm_cfg_setup Config Object Initialization function.

void fm_cfg_setup ( fm_cfg_t *cfg );

• fm_init Initialization function.

err_t fm_init ( fm_t *ctx, fm_cfg_t *cfg );

• fm_default_cfg Click Default Configuration function.

void fm_default_cfg ( fm_t *ctx );

• fm_get_received_signal_strength_indicator This function reads recived signal strength indicatior.

uint8_t fm_get_received_signal_strength_indicator ( fm_t *ctx );

• fm_get_channel_frequency This function calculates current channel frequency based on band and space settings.

float fm_get_channel_frequency ( fm_t *ctx );

• fm_get_channel This function reads CHANNEL bits from READCHAN register.

uint16_t fm_get_channel ( fm_t *ctx );

Application Init

Initializing I2C driver, powering up device, setting basic settings for Europe, setting values of seek threshold, volume, snr threshold and impulse detection threshold. Seek and memorize 5 radio stations with a signal strength above the set limit.

void application_init ( void )
{
    log_cfg_t log_cfg;
    fm_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.

    fm_cfg_setup( &cfg );
    FM_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    fm_init( &fm, &cfg );
    
    Delay_ms ( 500 );
    fm_default_cfg( &fm );

    memory = 0;
    mute = 0;
    fm_case_mute( &fm );
     
    for ( cnt = 0; cnt < 5;  )
    {
        log_printf( &logger, "seeking...\r\n" );
        do 
        {
            received_signal_strength_indicator = 0;
            fm_case_seek( &fm );
        }
        while ( received_signal_strength_indicator < SIGNAL_STRENGTH_LOWER_LIMIT ); //rssi value
        
        log_printf( &logger, "station found\r\n" );
        log_printf( &logger, "rssi: %u dBuV\r\n", received_signal_strength_indicator );
        log_printf( &logger, "channel frequency: %.2f MHz\r\n", channel_frequency );
        fm_case_memorize( );
        log_printf( &logger, "-----------------------\r\n" );
        Delay_ms ( 100 );
        cnt++;
    }  
    
    mute = 1;
    fm_case_mute( &fm );
    log_printf( &logger, "playing memorized stations...\r\n\r\n" );
}

Application Task

Tunes all memorized stations. Switches the stations each 10 seconds.

void application_task ( void )
{ 
    fm_case_station_1( &fm );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
       
    fm_case_station_2( &fm );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    
    fm_case_station_3( &fm );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    
    fm_case_station_4( &fm );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    
    fm_case_station_5( &fm );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
    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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