Nano_Modbus_Pyranometer_Baud

#include <SoftwareSerial.h>
#include <ModbusMaster.h>

#define RX_PIN 2
#define TX_PIN 3

#define CURRENT_SLAVE_ID 2    // Now communicating with ID 2
#define CURRENT_BAUD_RATE 4800

#define RENKE_REG_BAUD 0x07D1 // Baud rate EEPROM register
#define BAUD_CODE_9600 2      // 0=2400, 1=4800, 2=9600

SoftwareSerial modbusSerial(RX_PIN, TX_PIN);
ModbusMaster node;

void setup()
{
  Serial.begin(9600);
  while (!Serial);
  delay(1000);

  Serial.println("Renke Baud Rate Updater (Targeting ID 2)");
  Serial.println("----------------------------------------");

  modbusSerial.begin(CURRENT_BAUD_RATE);
  node.begin(CURRENT_SLAVE_ID, modbusSerial);

  delay(500);

  Serial.print("Writing Baud 9600 (Value: 2) to register 0x07D1... ");
  uint8_t result = node.writeSingleRegister(RENKE_REG_BAUD, BAUD_CODE_9600);

  if (result == node.ku8MBSuccess) {
    Serial.println("SUCCESS!");
  } else {
    // If the sensor switches its UART speed immediately, a timeout response is expected
    Serial.print("Response Code: 0x");
    Serial.print(result, HEX);
    Serial.println(" (Timeout is normal if UART switched instantly)");
  }

  Serial.println("----------------------------------------");
  Serial.println("Power cycle the 12V supply to finalize the 9600 baud setting.");
}

void loop() {}