Beginner
10 min

Safeguard your RS485 data with ADM2682E and STM32F031K6

Isolate, elevate, communicate: Unleash the power of RS485!

RS485 Isolator Click with Nucleo 32 with STM32F031K6 MCU

Published Oct 01, 2024

Click board™

RS485 Isolator Click

Dev. board

Nucleo 32 with STM32F031K6 MCU

Compiler

NECTO Studio

MCU

STM32F031K6

Our RS485 signal isolator empowers your communication network by providing robust isolation, ensuring reliable data transmission in industrial environments

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Hardware Overview

How does it work?

RS485 Isolator Click is based on the ADM2682E, a signal, and a power-isolated RS-485 transceiver with ESD protection from Analog Devices. The signal isolation is implemented on the logic side of the interface, which is achieved by having a digital isolation section and a transceiver section. The applied data to the RX and DE pins are referenced to a logic ground and coupled across an isolated barrier to appear at the transceiver section referenced to the isolated ground. Similarly, the single-ended receiver output signal, referenced to

isolated ground in the transceiver section, is coupled across the isolation barrier to appear at the RX pin referenced to logic ground. RS485 Isolator Click uses a standard 2-Wire UART interface to communicate with the host MCU. There is driver enable input DE, which enables the driver with logic HIGH. The receiver-enable input RE enables the receiver with a LOW logic state. There is also a TERM jumper, which adds a 120R termination resistor at the receiver side of the bus, which minimizes the reflections. The input/output

terminal is properly labeled A and B for receiver input and Z and Y for driver output. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

RS485 Isolator Click top side image
RS485 Isolator Click bottom side image

Features overview

Development board

Nucleo 32 with STM32F031K6 MCU board provides an affordable and flexible platform for experimenting with STM32 microcontrollers in 32-pin packages. Featuring Arduino™ Nano connectivity, it allows easy expansion with specialized shields, while being mbed-enabled for seamless integration with online resources. The

board includes an on-board ST-LINK/V2-1 debugger/programmer, supporting USB reenumeration with three interfaces: Virtual Com port, mass storage, and debug port. It offers a flexible power supply through either USB VBUS or an external source. Additionally, it includes three LEDs (LD1 for USB communication, LD2 for power,

and LD3 as a user LED) and a reset push button. The STM32 Nucleo-32 board is supported by various Integrated Development Environments (IDEs) such as IAR™, Keil®, and GCC-based IDEs like AC6 SW4STM32, making it a versatile tool for developers.

Nucleo 32 with STM32F031K6 MCU double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

ARM Cortex-M0

MCU Memory (KB)

32

Silicon Vendor

STMicroelectronics

Pin count

32

RAM (Bytes)

4096

You complete me!

Accessories

Click Shield for Nucleo-32 is the perfect way to expand your development board's functionalities with STM32 Nucleo-32 pinout. The Click Shield for Nucleo-32 provides two mikroBUS™ sockets to add any functionality from our ever-growing range of Click boards™. We are fully stocked with everything, from sensors and WiFi transceivers to motor control and audio amplifiers. The Click Shield for Nucleo-32 is compatible with the STM32 Nucleo-32 board, providing an affordable and flexible way for users to try out new ideas and quickly create prototypes with any STM32 microcontrollers, choosing from the various combinations of performance, power consumption, and features. The STM32 Nucleo-32 boards do not require any separate probe as they integrate the ST-LINK/V2-1 debugger/programmer and come with the STM32 comprehensive software HAL library and various packaged software examples. This development platform provides users with an effortless and common way to combine the STM32 Nucleo-32 footprint compatible board with their favorite Click boards™ in their upcoming projects.

Click Shield for Nucleo-32 accessories 1 image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Receiver Enable
PA11
RST
Driver Enable
PA4
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
UART TX
PA10
TX
UART RX
PA9
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

RS485 Isolator Click Schematic schematic

Step by step

Project assembly

Click Shield for Nucleo-144 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo 32 with STM32F031K6 MCU as your development board.

Click Shield for Nucleo-144 front image hardware assembly
Nucleo 144 with STM32L4A6ZG MCU front image hardware assembly
Stepper 22 Click front image hardware assembly
Prog-cut hardware assembly
Stepper 22 Click complete accessories setup image hardware assembly
Nucleo-32 with STM32 MCU Access MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
STM32 M4 Clicker HA MCU/Select Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware assembly

Track your results in real time

Application Output

1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.

2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.

3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.

Software Support

Library Description

This library contains API for RS485 Isolator Click driver.

Key functions:

  • rs485isolator_set_receiver_mode - Set receiver state.

  • rs485isolator_generic_read - Generic read function.

  • rs485isolator_generic_write - Generic write function.

Open Source

Code example

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.

/*!
 * \file 
 * \brief RS485 Isolator Click example
 * 
 * # Description
 * This example reads and processes data from RS485 Isolator clicks.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes driver.
 * 
 * ## Application Task  
 * Depending on the selected mode, it reads all the received data or sends the desired message
 * every 2 seconds.
 * 
 * ## Additional Function
 * - rs485isolator_process ( ) - The general process of collecting the received data.
 * 
 * @note
 * Wire connection guide : Driver(Master)       Slave
 *                                     Y   ->   A
 *                                     Z   ->   B
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "rs485isolator.h"
#include "string.h"

// Comment out the line below in order to switch the application mode to receiver
#define DEMO_APP_TRANSMITTER

#define TEXT_TO_SEND "MIKROE - RS485 Isolator click\r\n"

#define PROCESS_RX_BUFFER_SIZE 100

// ------------------------------------------------------------------ VARIABLES

static rs485isolator_t rs485isolator;
static log_t logger;

// ------------------------------------------------------- ADDITIONAL FUNCTIONS

static void rs485isolator_process ( void )
{
    uint8_t uart_rx_buffer[ PROCESS_RX_BUFFER_SIZE ] = { 0 };
    
    int32_t rsp_size = rs485isolator_generic_read( &rs485isolator, uart_rx_buffer, PROCESS_RX_BUFFER_SIZE );

    if ( rsp_size > 0 )
    {  
        log_printf( &logger, "Received data: " );
        
        for ( uint8_t check_buf_cnt = 0; check_buf_cnt < rsp_size; check_buf_cnt++ )
        {
            log_printf( &logger, "%c", uart_rx_buffer[ check_buf_cnt ] );
        }
        Delay_ms ( 100 );
        rsp_size = rs485isolator_generic_read( &rs485isolator, uart_rx_buffer, PROCESS_RX_BUFFER_SIZE );
        if ( rsp_size > 0 )
        { 
            for ( uint8_t check_buf_cnt = 0; check_buf_cnt < rsp_size; check_buf_cnt++ )
            {
                log_printf( &logger, "%c", uart_rx_buffer[ check_buf_cnt ] );
            }
        }
    }
    Delay_ms( 100 );
}

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    rs485isolator_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.
    rs485isolator_cfg_setup( &cfg );
    RS485ISOLATOR_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    rs485isolator_init( &rs485isolator, &cfg );
    
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
#ifdef DEMO_APP_TRANSMITTER
    rs485isolator_generic_write( &rs485isolator, TEXT_TO_SEND, strlen ( TEXT_TO_SEND ) );
    log_info( &logger, "---- Data sent ----" );
    Delay_ms( 2000 );
#else
    rs485isolator_process( );
#endif    
}

void main ( void )
{
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}

// ------------------------------------------------------------------------ END

Additional Support

Resources

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