ماژول مبدل TTL به RS485 دو طرفه

Master RS-485 Device Software

/*
 * SCM TTL To RS485 Master Software
 * Exercise the SCM TTL to RS485 Module.  This code runs on the first (Master)device.
 * Use the SCM_RS485_Slave_Test software for the second (Slave) device
 * This uses the SoftSerial.h library which comes with the Arduino IDE
 * Pins used for the soft serial port are fairly arbitrary and can be changed
 * as needed.  Just redefine them below.
 */
#include <SoftwareSerial.h>
const int SSERIAL_RX_PIN = 10;  //Soft Serial Receive pin
const int SSERIAL_TX_PIN = 11;  //Soft Serial Transmit pin

// Create Soft Serial Port object and define pins to use
SoftwareSerial RS485Serial(SSERIAL_RX_PIN, SSERIAL_TX_PIN); // RX, TX

int byteReceived;
//===============================================================================
//  Initialization
//===============================================================================
void setup()
{
  Serial.begin(9600);           // Start the built-in serial port
  Serial.println("Master Device");
  Serial.println("Type in upper window, press ENTER");
   
  RS485Serial.begin(9600);   // Start the RS485 soft serial port 
}
//===============================================================================
//  Main
//===============================================================================
void loop() 
{
  if (Serial.available())         // A char(byte) has been entered in the Serial Monitor
  {
    byteReceived = Serial.read();                   // Read the byte
    RS485Serial.write(byteReceived);                 // Send byte to Remote Arduino 
  }
  
  if (RS485Serial.available())            //Data from the Slave is available
   {
    byteReceived = RS485Serial.read();    // Read received byte
    Serial.write(byteReceived);           // Show on Serial Monitor
   }  
}

Slave RS-485 Device Software

/*
 * SCM TTL to RS485 Slave Software
 * Exercise the SCM TTL to RS485 Module.  This code runs on the second (slave)device.
 * Use the SCM_RS485_Master_Test software for the first (Master) device
 * This uses the SoftSerial.h library which comes with the Arduino IDE
 * Pins used for the soft serial port are fairly arbitrary and can be changed
 * as needed.  Just redefine them below.
 */
#include <SoftwareSerial.h>

const int SSERIAL_RX_PIN = 10;  //Soft Serial Receive pin
const int SSERIAL_TX_PIN = 11;  //Soft Serial Transmit pin

// Create Soft Serial Port object and define pins to use
SoftwareSerial RS485Serial(SSERIAL_RX_PIN, SSERIAL_TX_PIN);

int byteReceived;
int byteSent;
//===============================================================================
//  Initialization
//===============================================================================
void setup() 
{
  Serial.begin(9600);         // Start the built-in hardware serial port
  Serial.println("Slave Device");  
   
  RS485Serial.begin(9600);   // Start the RS485 soft serial port 
}
//===============================================================================
//  Main
//===============================================================================
void loop() 
{
  // Watch for data coming in on the soft serial port.  If found, send a copy to the 
  // hardware port to display on the local serial terminal and also echo a copy back out 
  // the soft serial port to the Master device  
  if (RS485Serial.available())        // If data has come in from Master
  {
    byteSent = RS485Serial.read();    // Read the byte 
    Serial.write(byteSent);           // Show on local Serial Monitor window
    delay(10);              
 
    RS485Serial.write(byteSent);                     // Send the byte back to Master
  }  
}