RS485 simple

RS485_simple.ino

#include <SoftwareSerial.h>

const byte receivePin = 8;         // green cable (RO)
const byte transmitPin = 9;        // orange cable (DI)
const byte receiveEnablePin = 2;   // blue cable (RE)

const byte RECEIVER_ENABLED = 0;
const byte RECEIVER_DISABLED = 1;

const byte LED_PIN = 13;

SoftwareSerial rs485(receivePin, transmitPin);  // receive pin, transmit pin

void fWrite( const byte * what, byte len )
{
  int i;
  for(i=0;i<len;i++)
  {
    rs485.write(what[i]);
  }
}

void fWrite( const byte what )
{
  rs485.write(what);
}

int fAvailable()
{
  return rs485.available();
}

int fRead()
{
  return rs485.read();
}

void setup() {
  Serial.begin( 9600 );
  rs485.begin( 9600 );
  pinMode( LED_PIN, OUTPUT );  // built-in LED
  pinMode( transmitPin, OUTPUT );
  pinMode( receivePin, INPUT );
  pinMode( receiveEnablePin, OUTPUT);

  readMode();
}

void loop() {
  while( fAvailable() ){
    char c = fRead();
    Serial.print( c );
  }
  
  if( Serial.available() ){
    write();
  }
}
void write()
{
  writeMode();
  //delay(1);
  while( Serial.available() ){
    char ch = Serial.read();
    Serial.print(ch);
    fWrite(ch);
  }
  //delay(1);
  readMode();
}
void readMode()
{
  digitalWrite(receiveEnablePin, RECEIVER_ENABLED);    // RE = 0
}

void writeMode()
{
  digitalWrite(receiveEnablePin, RECEIVER_DISABLED);  // RE = 1
}