rs4857

\mainpage Main Page

---

RS485 7 Click

RS485 7 Click is a compact add-on board that enables communication over an RS485 network. This board features the THVD1424, a full duplex RS485 transceiver with a selectable data rate from Texas Instruments. The THVD1424 offers several pin-controlled features, including an on-chip 120Ω termination resistor, slew rate control, and the ability to switch between half and full duplex mode. With its high immunity to IEC Contact Discharge ESD events, the bus pins require no additional system-level protection components. Additionally, the chip is known for its low power consumption and glitch-free power-up/power-down functionality, which enables hot plug-in capability.

Click Product page

---

Click library

• Author : Nenad Filipovic
• Date : Mar 2023.
• Type : UART type

Software Support

We provide a library for the RS485 7 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 7 Click driver.

Standard key functions :

• rs4857_cfg_setup Config Object Initialization function.

void rs4857_cfg_setup ( rs4857_cfg_t *cfg );

• rs4857_init Initialization function.

err_t rs4857_init ( rs4857_t *ctx, rs4857_cfg_t *cfg );

Example key functions :

• rs4857_receiver_enable RS485 7 enables the receiver function.

void rs4857_receiver_enable ( rs4857_t *ctx );

• rs4857_driver_enable RS485 7 enables the driver function.

void rs4857_driver_enable ( rs4857_t *ctx );

Example Description

This example reads and processes data from RS485 7 clicks. The library also includes a function for enabling/disabling the receiver or driver and data writing or reading.

The demo application is composed of two sections :

Application Init

Initializes driver performs wake-up module and enables the selected mode.

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    rs4857_cfg_t rs4857_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.
    rs4857_cfg_setup( &rs4857_cfg );
    RS4857_MAP_MIKROBUS( rs4857_cfg, MIKROBUS_1 );
    if ( UART_ERROR == rs4857_init( &rs4857, &rs4857_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
    app_buf_len = 0;
    
    rs4857_termination_xy_enable( &rs4857 );
    rs4857_termination_ab_enable( &rs4857 );
    
    rs4857_receiver_enable( &rs4857 );
    rs4857_driver_enable( &rs4857 );
    Delay_ms ( 100 );
}

Application Task

This example demonstrates the use of the RS485 7 Click board™. The app sends a "MikroE" message, reads the received data and parses it. Results are being sent to the UART Terminal, where you can track their changes.

void application_task ( void ) 
{  
    if ( rs4857_generic_write( &rs4857, DEMO_MESSAGE, 10 ) )
    {
        rs4857_process( );
        if ( app_buf_len > 0 )
        {
            log_printf( &logger, "%s", app_buf );
            rs4857_clear_app_buf( );
        }
    }
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

Note

Operation Mode: Full duplex. Transmitter: Y and Z. Receiver: A and B. Wire connection: Y-A, Z-B.

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.RS4857

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.

---