Expand 12 Click

Expand 12 Click is a compact add-on board that contains a multi-port I/O expander. This board features the MAX7300, a general-purpose I/O expander providing remote I/O expansion for most MCU’s families from Maxim Integrated, now part of Analog Devices. The MAX7300 comes in a 28-port configuration and allows easy addition of I/O through a standard I2C serial interface. Each port is user-configurable to either a logic input or logic output, capable of sinking 10mA and sourcing 4.5mA.

Click Product page

Click library

• Author : Stefan Filipovic
• Date : Sep 2021.
• Type : I2C type

Software Support

We provide a library for the Expand12 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 Expand12 Click driver.

Standard key functions :

• expand12_cfg_setup Config Object Initialization function.

  void expand12_cfg_setup ( expand12_cfg_t *cfg );

• expand12_init Initialization function.

  err_t expand12_init ( expand12_t *ctx, expand12_cfg_t *cfg );

• expand12_default_cfg Click Default Configuration function.

  err_t expand12_default_cfg ( expand12_t *ctx );

Example key functions :

• expand12_set_pin_direction This function sets the direction of the selected pin.

  err_t expand12_set_pin_direction ( expand12_t *ctx, uint8_t pin, uint8_t direction );

• expand12_set_pin_value This function sets the logic level of the selected pin.

  err_t expand12_set_pin_value ( expand12_t *ctx, uint8_t pin, uint8_t pin_value );

• expand12_read_all_pins_value This function reads all pins logic levels.

  err_t expand12_read_all_pins_value ( expand12_t *ctx, uint32_t *pins_value );

Example Description

This example demonstrates the use of Expand 12 Click board.

The demo application is composed of two sections :

Application Init

Initializes the driver and performs the Click default configuration which sets the first three ports (pins 4-23) as output and the fourth port (pins 24-31) as input with pull-ups.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    expand12_cfg_t expand12_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.
    expand12_cfg_setup( &expand12_cfg );
    EXPAND12_MAP_MIKROBUS( expand12_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == expand12_init( &expand12, &expand12_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

    if ( EXPAND12_ERROR == expand12_default_cfg ( &expand12 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }

    log_info( &logger, " Application Task " );
}

Application Task

Sets the pins of the first three ports and then reads the status of all pins and displays the result on the USB UART approximately every 100 miliseconds.

void application_task ( void )
{
    static uint8_t port_value = 0;
    static uint32_t pins_status = 0;

    expand12_set_port_value( &expand12, EXPAND12_PORT_4_7, EXPAND12_ALL_PINS, port_value );
    expand12_set_port_value( &expand12, EXPAND12_PORT_8_15, EXPAND12_ALL_PINS, port_value );
    expand12_set_port_value( &expand12, EXPAND12_PORT_16_23, EXPAND12_ALL_PINS, port_value++ );

    expand12_read_all_pins_value( &expand12, &pins_status );
    log_printf( &logger, " Pins status (32-bit) : 0x%.8LX\r\n\n", pins_status );
    Delay_ms ( 100 );
}

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.Expand12

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. UART terminal is available in all MikroElektronika compilers.