ibutton

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iButton Click

iButton 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 : Stefan Filipovic
• Date : Feb 2024.
• Type : One Wire type

Software Support

Example Description

This example demonstrates the use of the iButton Click boards by registering a DS1990A Serial Number iButton key and then waiting until a key is detected on the reader and identifying if the key matches one of those stored in RAM.

Example Libraries

• MikroSDK.Board
• MikroSDK.Log
• Click.iButton

Example Key Functions

• ibutton_cfg_setup Config Object Initialization function.

void ibutton_cfg_setup ( ibutton_cfg_t *cfg );

• ibutton_init Initialization function.

err_t ibutton_init ( ibutton_t *ctx, ibutton_cfg_t *cfg );

• ibutton_add_key This function reads the ROM address from a DS1990A Serial Number iButton and stores it in the ctx->key_rom buffer.

err_t ibutton_add_key ( ibutton_t *ctx );

• ibutton_remove_keys This function removes all stored keys by clearing the ctx->key_rom buffer.

void ibutton_remove_keys ( ibutton_t *ctx );

• ibutton_check_key This function reads the ROM address from a DS1990A Serial Number iButton and checks if it is already stored in the ctx->key_rom buffer.

err_t ibutton_check_key ( ibutton_t *ctx );

Application Init

Initializes the driver and registers a new DS1990A Serial Number iButton key and stores it in RAM.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    ibutton_cfg_t ibutton_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.
    ibutton_cfg_setup( &ibutton_cfg );
    IBUTTON_MAP_MIKROBUS( ibutton_cfg, MIKROBUS_1 );
    if ( ONE_WIRE_ERROR == ibutton_init( &ibutton, &ibutton_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    ibutton_register_keys ( &ibutton, NUMBER_OF_KEYS );
    
    log_info( &logger, " Application Task " );
}

Application Task

Waits until a key is detected on the reader, and checks if there's a key found in the library that matches the one it has just read. All data is being logged on the USB UART where you can track the program flow.

void application_task ( void )
{
    err_t error_flag = IBUTTON_OK;
    ibutton_led_indication ( &ibutton, IBUTTON_LED_DISABLE );
    log_printf( &logger, " >>> Waiting for a key <<<\r\n" );
    do
    {
        ibutton_led_indication ( &ibutton, IBUTTON_LED_WAIT_KEY );
        error_flag = ibutton_check_key ( &ibutton );
    }
    while ( IBUTTON_ERROR == error_flag );

    ibutton_led_indication ( &ibutton, IBUTTON_LED_DISABLE );
    if ( IBUTTON_OK == error_flag )
    {
        log_printf( &logger, " MATCH, access allowed!\r\n" );
        ibutton_led_indication ( &ibutton, IBUTTON_LED_SUCCESS );
    }
    else if ( IBUTTON_KEY_NO_MATCH == error_flag )
    {
        log_printf( &logger, " NO MATCH, access denied!\r\n" );
        ibutton_led_indication ( &ibutton, IBUTTON_LED_WRONG_KEY );
    }
    ibutton_led_indication ( &ibutton, IBUTTON_LED_DISABLE );
    log_printf( &logger, "--------------------------------\r\n\n" );
    Delay_ms ( 500 );
}

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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