Expand 8 click

Expand 8 Click is a compact add-on board that contains a multi-port I/O expander with bi-directional input/outputs. This board features the MAX7317, 10-Port SPI-interfaced I/O expander with overvoltage and hot-insertion protection from Maxim Integrated.

click Product page

Click library

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

Software Support

We provide a library for the Expand8 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 Expand8 Click driver.

Standard key functions :

• expand8_cfg_setup Config Object Initialization function.

  void expand8_cfg_setup ( expand8_cfg_t *cfg );

• expand8_init Initialization function.

  err_t expand8_init ( expand8_t *ctx, expand8_cfg_t *cfg );

Example key functions :

• expand8_write_data Generic write data function.

  void expand8_write_data ( expand8_t *ctx, uint8_t addr, uint8_t tx_data );

• expand8_read_data Generic read data function.

  uint8_t expand8_read_data ( expand8_t *ctx, uint8_t addr );

• expand8_set_port Set port function.

  err_t expand8_set_port ( expand8_t *ctx, uint8_t sel_port, uint8_t sel_imped );

Example Description

This is an example that demonstrates the use of the Expand 8 click board.

The demo application is composed of two sections :

Application Init

Initialization driver enables - SPI, also write log.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    expand8_cfg_t expand8_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.

    expand8_cfg_setup( &expand8_cfg );
    EXPAND8_MAP_MIKROBUS( expand8_cfg, MIKROBUS_1 );
    err_t init_flag  = expand8_init( &expand8, &expand8_cfg );
    if ( SPI_MASTER_ERROR == init_flag ) {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    log_info( &logger, " Application Task " );
    select_port = EXPAND8_ADDR_OUT_LVL_PORT_P0;
    Delay_ms ( 100 );
}

Application Task

This example is working by toggling each of 10 available ports every 1 second. Results are being sent to the Uart Terminal where you can track their changes.

void application_task ( void )
{
    expand8_set_port( &expand8, select_port, EXPAND8_SET_LOW_IMPEDANCE );

    log_printf( &logger, "     Port P%d - ON\r\n", ( uint16_t ) select_port );
    log_printf( &logger, "- - - - - - - - - - -\r\n" );
    Delay_ms ( 1000 );

    expand8_set_port( &expand8, select_port, EXPAND8_SET_HIGH_IMPEDANCE );

    log_printf( &logger, "     Port P%d - OFF\r\n", ( uint16_t ) select_port );
    log_printf( &logger, "---------------------\r\n" );
    Delay_ms ( 1000 );

    select_port++;

    if ( select_port > EXPAND8_ADDR_OUT_LVL_PORT_P9 ) {
        select_port = EXPAND8_ADDR_OUT_LVL_PORT_P0;
    }
}

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.Expand8

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.