#include <SoftwareSerial.h>

SoftwareSerial RS485Serial(2, 3); // RX, TX

void setup() {
  pinMode(4, OUTPUT); // Control the DE/RE pin
  digitalWrite(4, HIGH); // Set to transmit mode
  RS485Serial.begin(9600);
}

void loop() {
  RS485Serial.println("Hello from Arduino!");
  delay(1000);
}