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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.
- Author : Stefan Filipovic
- Date : Jun 2024.
- Type : UART type
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.
This library contains API for RS485 Isolator 4 Click driver.
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 );
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 );
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 :
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 " );
}
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
}
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.