RS485 Isolator 4 Click

RS485 Isolator 4 Click is a compact add-on board designed for robust RS-485 and RS-422 half-duplex communication with galvanic isolation. This board features the ISO1450, a 5kVRMS isolated RS-485 transceiver from Texas Instruments. The ISO1450 supports data rates up to 50Mbps and features advanced protection against electrostatic discharge (ESD) and electrical fast transients (EFT), ensuring reliable long-distance communication in industrial environments. It operates over a wide supply voltage range (3V to 5.5V), offering failsafe protection against open, short, and idle bus states.

Click Product page

Click library

• Author : Stefan Filipovic
• Date : Jun 2024.
• Type : UART type

Software Support

We provide a library for the RS485 Isolator 4 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 RS485 Isolator 4 Click driver.

Standard key functions :

• rs485isolator4_cfg_setup Config Object Initialization function.

  void rs485isolator4_cfg_setup ( rs485isolator4_cfg_t *cfg );

• rs485isolator4_init Initialization function.

  err_t rs485isolator4_init ( rs485isolator4_t *ctx, rs485isolator4_cfg_t *cfg );

Example key functions :

• rs485isolator4_generic_write This function writes a desired number of data bytes by using UART serial interface.

  err_t rs485isolator4_generic_write ( rs485isolator4_t *ctx, uint8_t *data_in, uint16_t len );

• rs485isolator4_generic_read This function reads a desired number of data bytes by using UART serial interface.

  err_t rs485isolator4_generic_read ( rs485isolator4_t *ctx, uint8_t *data_out, uint16_t len );

• rs485isolator4_driver_enable This function enables the driver input by setting the DE pin to high logic state.

  void rs485isolator4_driver_enable ( rs485isolator4_t *ctx );

Example Description

This example demonstrates the use of an RS485 Isolator 4 Click board by showing the communication between the two Click board configured as a receiver and transmitter.

The demo application is composed of two sections :

Application Init

Initializes the driver and logger and displays the selected application mode.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    rs485isolator4_cfg_t rs485isolator4_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.
    rs485isolator4_cfg_setup( &rs485isolator4_cfg );
    RS485ISOLATOR4_MAP_MIKROBUS( rs485isolator4_cfg, MIKROBUS_1 );
    if ( UART_ERROR == rs485isolator4_init( &rs485isolator4, &rs485isolator4_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }

#ifdef DEMO_APP_TRANSMITTER
    rs485isolator4_driver_enable ( &rs485isolator4 );
    rs485isolator4_receiver_disable ( &rs485isolator4 );
    log_printf( &logger, " Application Mode: Transmitter\r\n" );
#else
    rs485isolator4_driver_disable ( &rs485isolator4 );
    rs485isolator4_receiver_enable ( &rs485isolator4 );
    log_printf( &logger, " Application Mode: Receiver\r\n" );
#endif
    log_info( &logger, " Application Task " );
}

Application Task

Depending on the selected mode, it reads all the received data or sends the desired message every 2 seconds.

void application_task ( void )
{
#ifdef DEMO_APP_TRANSMITTER
    rs485isolator4_generic_write( &rs485isolator4, DEMO_TEXT_MESSAGE, strlen( DEMO_TEXT_MESSAGE ) );
    log_printf( &logger, "%s", ( char * ) DEMO_TEXT_MESSAGE );
    Delay_ms( 1000 );
    Delay_ms( 1000 );
#else
    uint8_t rx_data = 0;
    if ( rs485isolator4_generic_read( &rs485isolator4, &rx_data, 1 ) > 0 )
    {
        log_printf( &logger, "%c", rx_data );
    }
#endif
}

Note

Make sure to provide a power supply voltage to isolated VCC_EXT and GND pins in a range from 3V to 5.5V.

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.RS485Isolator4

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.