expand3  2.1.0.0
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Expand 3 click

Expand 3 Click is a compact add-on board providing general-purpose I/O expansion. This board features the DS2408, an 8-channel programmable I/O expander from Analog Devices. The DS2408 has a factory-lasered 64-bit registration number, enabling multiple Expand 3 Click boards™ to be connected on the same data line, communicating with the host MCU through a standard Dallas Semiconductor 1-Wire interface (15.3kbps or 100kbps). PIO outputs are configured as open-drain and provide a maximum on-resistance of 100Ω.

click Product page


Click library

  • Author : Stefan Filipovic
  • Date : Feb 2024.
  • Type : One Wire type

Software Support

We provide a library for the Expand 3 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 Expand 3 Click driver.

Standard key functions :

Example key functions :

  • expand3_write_state This function writes data to the PIO output-latch state register which controls the open-drain output transistors of the PIO channels.
    err_t expand3_write_state ( expand3_t *ctx, uint8_t state );
  • expand3_read_last_state This function reads the latest data written to the PIO using
    err_t expand3_read_last_state ( expand3_t *ctx, uint8_t *last_state );
  • expand3_read_current_state This function reads the current logic state of the PIO pins.
    err_t expand3_read_current_state ( expand3_t *ctx, uint8_t *curr_state );

Example Description

This example demonstrates the use of Expand 3 click board by setting and reading the port state.

The demo application is composed of two sections :

Application Init

Initializes the driver and performs the click default configuration.

void application_init ( void )
{
log_cfg_t log_cfg;
expand3_cfg_t expand3_cfg;
LOG_MAP_USB_UART( log_cfg );
log_init( &logger, &log_cfg );
log_info( &logger, " Application Init " );
// Click initialization.
expand3_cfg_setup( &expand3_cfg );
EXPAND3_MAP_MIKROBUS( expand3_cfg, MIKROBUS_1 );
if ( ONE_WIRE_ERROR == expand3_init( &expand3, &expand3_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( EXPAND3_ERROR == expand3_default_cfg ( &expand3 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}

Application Task

Writes a counter data to the port output pins and reads the status of the same port input pins approximately every 500ms. All data are displayed on the USB UART.

void application_task ( void )
{
static uint8_t out_state = 0;
static uint8_t in_state = 0;
if ( ( EXPAND3_OK == expand3_write_state ( &expand3, out_state ) ) &&
( EXPAND3_OK == expand3_read_last_state ( &expand3, &out_state ) ) )
{
log_printf( &logger, " Output state: 0x%.2X\r\n\n", out_state++ );
}
if ( EXPAND3_OK == expand3_read_current_state ( &expand3, &in_state ) )
{
log_printf( &logger, " Input state: 0x%.2X\r\n\n", in_state );
}
Delay_ms ( 500 );
}

Note

The PIO pins are in the open-drain mode, therefore a pull-up resistor must be added to each pin.

This click board can be used in a combination with an EasyLED [MIKROE-571] and EasyPULL [MIKROE-575] boards.

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.Expand3

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.


expand3_cfg_t
Expand 3 Click configuration object.
Definition: expand3.h:200
expand3_cfg_setup
void expand3_cfg_setup(expand3_cfg_t *cfg)
Expand 3 configuration object setup function.
EXPAND3_OK
@ EXPAND3_OK
Definition: expand3.h:218
expand3_t
Expand 3 Click context object.
Definition: expand3.h:183
application_task
void application_task(void)
Definition: main.c:70
expand3_default_cfg
err_t expand3_default_cfg(expand3_t *ctx)
Expand 3 default configuration function.
expand3_read_current_state
err_t expand3_read_current_state(expand3_t *ctx, uint8_t *curr_state)
Expand 3 read current state function.
expand3_init
err_t expand3_init(expand3_t *ctx, expand3_cfg_t *cfg)
Expand 3 initialization function.
EXPAND3_MAP_MIKROBUS
#define EXPAND3_MAP_MIKROBUS(cfg, mikrobus)
MikroBUS pin mapping.
Definition: expand3.h:159
expand3_write_state
err_t expand3_write_state(expand3_t *ctx, uint8_t state)
Expand 3 write state function.
application_init
void application_init(void)
Definition: main.c:34
expand3_read_last_state
err_t expand3_read_last_state(expand3_t *ctx, uint8_t *last_state)
Expand 3 read last state function.
EXPAND3_ERROR
@ EXPAND3_ERROR
Definition: expand3.h:219