HW-0519 TTL to RS485 Module

// HW-0519 Auto-Flow RS485 Module
// Simple serial pass-through demo for Arduino Uno.
// Upload this sketch, then open Serial Monitor at 9600 baud.
// Type a message and press Enter; it will be sent to the RS485 module.

void setup() {
  Serial.begin(9600);
  while (!Serial) {
    ;
  }

  Serial.println("HW-0519 RS485 module demo");
  Serial.println("Arduino Uno hardware serial on D0/D1");
  Serial.println("Connect your RS485 bus to A+ and B-.");
  Serial.println("Type in Serial Monitor to send data.");
}

void loop() {
  // Send any bytes typed in the USB Serial Monitor out through the RS485 module.
  while (Serial.available() > 0) {
    char c = (char)Serial.read();
    Serial.write(c);
  }
}