ArdunioRs485.ino

/*-----( Import needed libraries )-----*/
#include <SoftwareSerial.h>

/*-----( Declare Constants and Pin Numbers )-----*/
#define SSerialRX        10  //Serial Receive  pin RO   (receive out)
#define SSerialTX        11  //Serial Transmit pin DI   (data in)

#define SSerialTxControl 3   //RS485 Direction control (DE&RE jump together to pin3)

#define RS485Transmit    HIGH  //  status ： send data via 485
#define RS485Receive     LOW   //   status： Rcv data via 485

#define Pin13LED         13  

/*-----( Declare objects )-----*/
SoftwareSerial RS485Serial(SSerialRX, SSerialTX); // RX, TX 

/*-----( Declare Variables )-----*/
char rcvData;
char sendData;

void setup()   /****** SETUP: RUNS ONCE ******/
{
  // Start the built-in serial port, probably to Serial Monitor
  Serial.begin(9600);
  Serial.println("SerialRemote");  // Can be ignored
  
  pinMode(Pin13LED, OUTPUT);   
  pinMode(SSerialTxControl, OUTPUT);  
  
  digitalWrite(SSerialTxControl, RS485Receive);  // Init Transceiver
  
  // Start the software serial port, to another device
  RS485Serial.begin(4800);   // set the data rate 
}//--(end setup )---


void loop()   /****** LOOP: RUNS CONSTANTLY ******/
{
  //digitalWrite(Pin13LED, HIGH);  // Show activity
  //Copy input data to output  
//  digitalWrite(SSerialTxControl, RS485Transmit); 
  
  if (RS485Serial.available()>0) 
  {
    digitalWrite(Pin13LED, HIGH);
    rcvData = RS485Serial.read();   // Read the byte 
    Serial.println("inbyteReceived:");
    Serial.println(rcvData);      
    //digitalWrite(Pin13LED, LOW); 
    delay(1000); 

    digitalWrite(SSerialTxControl, RS485Transmit);  
    RS485Serial.write(rcvData); 
    digitalWrite(SSerialTxControl, RS485Receive); 
     
    
 
  }// End If RS485SerialAvailable
 
}//--(end main loop )---