4x4 Key Click

4x4 Key Click carries a 16 button keypad. The design of the board — inputs are read by a pair of connected 8-bit parallel-in serial-out shift registers — allows for multiple key presses at the same time.

Click Product page

Click library

• Author : Nenad Filipovic
• Date : Nov 2019.
• Type : SPI type

Software Support

We provide a library for the 4x4Key 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 form compilers IDE(recommended way), or downloaded from our LibStock, or found on mikroE github account.

Library Description

This library contains API for 4x4Key Click driver.

Standard key functions :

• Config Object Initialization function.

  void c4x4key_cfg_setup ( c4x4key_cfg_t *cfg );

• Initialization function.

  C4X4KEY_RETVAL c4x4key_init ( c4x4key_t ctx, c4x4key_cfg_t cfg );

• Click Default Configuration function.

  void c4x4key_default_cfg ( c4x4key_t *ctx );

Example key functions :

• Get 16-bit data function.

  uint16_t c4x4key_get_data ( c4x4key_t *ctx );

• Get position pressed button function.

  uint8_t c4x4key_get_btn_position ( c4x4key_t *ctx );

Examples Description

This is a example which demonstrates the use of 4x4 Key Click board. Detects and logs whether any of the buttons is pressed.

The demo application is composed of two sections :

Application Init

Configuring clicks and log objects.

void application_init ( void )
{
    log_cfg_t log_cfg;
    c4x4key_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_printf( &logger, "- Application Init -\r\n" );
    log_printf( &logger, "--------------------\r\n" );

    //  Click initialization.

    c4x4key_cfg_setup( &cfg );
    C4X4KEY_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    c4x4key_init( &c4x4key, &cfg );

    btn_data_old = 0;

    log_printf( &logger, "   4x4 Key Click\r\n" );
    log_printf( &logger, "--------------------\r\n" );
    log_printf( &logger, "  Press any button\r\n" );
    log_printf( &logger, "--------------------\r\n" );
}

Application Task

This is a example which demonstrates the use of 4x4 Key Click board. Detects and logs whether any of the buttons is pressed. Results are being sent to the Usart Terminal where you can track their changes. All data logs on usb uart when the button is triggered.

void application_task ( void )
{
    uint16_t btn_data;

    btn_data = c4x4key_get_data( &c4x4key );

    if ( btn_data_old != btn_data )
    {
        if ( btn_data == C4X4KEY_BUTTON_0 )
        {
            log_printf( &logger, "         0\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_1 )
        {
            log_printf( &logger, "         1\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_2 )
        {
            log_printf( &logger, "         2\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_3 )
        {
            log_printf( &logger, "         3\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_4 )
        {
            log_printf( &logger, "         4\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_5 )
        {
            log_printf( &logger, "         5\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_6 )
        {
            log_printf( &logger, "         6\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_7 )
        {
            log_printf( &logger, "         7\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_8 )
        {
            log_printf( &logger, "         8\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_9 )
        {
            log_printf( &logger, "         9\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_A )
        {
            log_printf( &logger, "         A\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_B )
        {
            log_printf( &logger, "         B\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_C )
        {
            log_printf( &logger, "         C\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_D )
        {
            log_printf( &logger, "         D\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_STAR )
        {
            log_printf( &logger, "         *\r\n" );
        }

        if ( btn_data == C4X4KEY_BUTTON_HASH )
        {
            log_printf( &logger, "         #\r\n" );
        }

        btn_data_old = btn_data;
    }
} 

The full application code, and ready to use projects can be installed directly form compilers IDE(recommneded) or found on LibStock page or mikroE GitHub accaunt.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.4x4Key

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. The terminal available in all Mikroelektronika compilers, or any other terminal application of your choice, can be used to read the message.