Expand 2 click

EXPAND 2 click is an accessory board in mikroBUS form factor. It includes a 16-bit I/O expander MCP23017 with I²C clock speeds up to 10 MHz for higher throughput applications.

click Product page

Click library

• Author : MikroE Team
• Date : May 2020.
• Type : I2C type

Software Support

We provide a library for the Expand2 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 Expand2 Click driver.

Standard key functions :

• Config Object Initialization function.

  void expand2_cfg_setup ( expand2_cfg_t *cfg );

• Initialization function.

  EXPAND2_RETVAL expand2_init ( expand2_t ctx, expand2_cfg_t cfg );

• Click Default Configuration function.

  void expand2_default_cfg ( expand2_t *ctx );

Example key functions :

• Function set bit to 8-bit register address from PORTA of MCP23017 chip.

  void expand2_set_bit_port_a ( expand2_t *ctx, uint8_t module_address, uint8_t bit_mask );

• Function toggle bit from 8-bit register address from PORTA of MCP23017 chip.

  void expand2_toggle_bit_port_a ( expand2_t *ctx, uint8_t module_address, uint8_t bit_mask );

• Function clear bit from 8-bit register address from PORTA of MCP23017 chip.

  void expand2_clear_bit_port_a ( expand2_t *ctx, uint8_t moduleAddress, uint8_t bitMask );

Examples Description

This application demonstrates the use of the Expand 2 click board.

The demo application is composed of two sections :

Application Init

Initializes the driver and logger, and then sets the click default configuration: PORTA as output, PORTB as input with pull-ups on all pins.

void application_init ( void )
{
    log_cfg_t log_cfg;
    expand2_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_info( &logger, "---- Application Init ----" );

    //  Click initialization.

    expand2_cfg_setup( &cfg );
    EXPAND2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    expand2_init( &expand2, &cfg );

    expand2_default_cfg ( &expand2 );

    log_printf( &logger, "----------------\r\n" );
    log_printf( &logger, " Expand 2 Click \r\n" );
    log_printf( &logger, "----------------\r\n" );

    Delay_ms ( 100 );
}

Application Task

Sets other pin of PORTA every 3 seconds, then reads and displays the status of both ports on USB UART.

void application_task ( void )
{
    //  Task implementation.

    uint8_t port_status;
    uint8_t pin_position;

    for ( pin_position = 0; pin_position < 8; pin_position++ )
    {
        expand2_set_port_a( &expand2, EXPAND2_I2C_MODULE_ADDRESS_0, pin_position );

        port_status = expand2_read_port_a( &expand2, EXPAND2_I2C_MODULE_ADDRESS_0 );

        log_printf( &logger, " Status PA (output): %d\r\n", (uint16_t) port_status );

        port_status = expand2_read_port_b( &expand2, EXPAND2_I2C_MODULE_ADDRESS_0 );

        log_printf( &logger, " Status PB (input) : %d  \r\n", (uint16_t) port_status );
        log_printf( &logger, "----------------\r\n" );

        Delay_ms ( 1000 );
        Delay_ms ( 1000 );
        Delay_ms ( 1000 );
    }
}

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.Expand2

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.