#include <SoftwareSerial.h>

// RS485 pins
#define RS485_RO 10
#define RS485_DI 11
#define RS485_RE 2
#define RS485_DE 3

#define SENSOR_PIN A1

SoftwareSerial rs485(RS485_RO, RS485_DI); // RX, TX

void setup() {
  pinMode(RS485_RE, OUTPUT);
  pinMode(RS485_DE, OUTPUT);

  // Start in transmit mode
  digitalWrite(RS485_RE, HIGH);
  digitalWrite(RS485_DE, HIGH);

  Serial.begin(9600);
  rs485.begin(9600);

  Serial.println("RS485 TX Started");
}

void loop() {
  int sensorValue = analogRead(SENSOR_PIN); // 0–1023

  rs485.print(sensorValue);
  rs485.print('\n');   // newline as packet end

  Serial.print("Sent: ");
  Serial.println(sensorValue);

  delay(200); // send every 200 ms
}
