8x8 B Click

8x8 B Click is a 64 LED matrix display Click board™, composed of SMD LEDs organized in 8 rows by 8 columns. It has a digital brightness control in 16 steps, it can control every LED in the display matrix independently, it blanks the display on power up to eliminate glitches and it requires a single resistor to control the current through all the LEDs at once, which simplifies the design. 8x8 B Click uses a fast SPI communication protocol, allowing fast display response and no lag.

Click Product page

Click library

• Author : Stefan Ilic
• Date : Jun 2021.
• Type : SPI type

Software Support

We provide a library for the 8X8B 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 8X8B Click driver.

Standard key functions :

• c8x8b_cfg_setup Config Object Initialization function.

  void c8x8b_cfg_setup ( c8x8b_cfg_t *cfg );

• c8x8b_init Initialization function.

  err_t c8x8b_init ( c8x8b_t *ctx, c8x8b_cfg_t *cfg );

• c8x8b_default_cfg Click Default Configuration function.

  void c8x8b_default_cfg ( c8x8b_t *ctx );

Example key functions :

• c8x8b_write_cmd This function writes a desired number of data bytes starting from the selected register by using SPI serial interface.

  void c8x8b_write_cmd ( c8x8b_t *ctx, uint8_t cmd, uint8_t tx_data  );

• c8x8b_display_refresh The function switches off all LEDs.

  void c8x8b_display_refresh ( c8x8b_t *ctx );

• c8x8b_display_byte This function displayes one character to the display.

  void c8x8b_display_byte ( c8x8b_t *ctx, char tx_byte );

Example Description

This demo example shows a drawing of Image, new create string and character on the screen.

The demo application is composed of two sections :

Application Init

Configuring clicks and log objects. Settings the Click in the default configuration.

void application_init ( void ) {
    log_cfg_t log_cfg;  /**< Logger config object. */
    c8x8b_cfg_t c8x8b_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.

    c8x8b_cfg_setup( &c8x8b_cfg );
    C8X8B_MAP_MIKROBUS( c8x8b_cfg, MIKROBUS_1 );
    err_t init_flag  = c8x8b_init( &c8x8b, &c8x8b_cfg );
    if ( init_flag == SPI_MASTER_ERROR ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    c8x8b_default_cfg ( &c8x8b );
    log_info( &logger, " Application Task " );
    Delay_1sec( );
}

Application Task

Shows one byte, then scrolls the string and image, every 1 sec.

void application_task ( void ) {
    c8x8b_display_byte( &c8x8b, demo_char );
    Delay_ms ( 1000 );

    c8x8b_display_string( &c8x8b, &demo_string[ 0 ] );
    Delay_ms ( 1000 );

    c8x8b_display_image( &c8x8b, &demo_img_on[ 0 ] );
    Delay_ms ( 500 );

    c8x8b_display_image( &c8x8b, &demo_img_off[ 0 ] );
    Delay_ms ( 1000 );
}

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.8X8B

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.