[arduino code examples for A6v3]-04 RS485 communication test

Code:
/*

 * Made by KinCony IoT: https://www.kincony.com

 *

 * RS485 Communication Test with Echo

 *

 * This program tests RS485 communication using ESP32-S3.

 * It sends a message over RS485, reads incoming messages, and echoes them back.

 * The TXD pin is defined as GPIO 9 and RXD pin is defined as GPIO 8.

 */



#include <HardwareSerial.h>



// Define RS485 pins

#define RS485_RXD 18

#define RS485_TXD 17



// Create a hardware serial object

HardwareSerial rs485Serial(1);



void setup() {

  // Start serial communication for debugging

  Serial.begin(115200);

  while (!Serial);



  // Initialize RS485 Serial communication

  rs485Serial.begin(9600, SERIAL_8N1, RS485_RXD, RS485_TXD);

  

  Serial.println("RS485 Test Start");

}



void loop() {

  // Send a test message periodically

 // rs485Serial.println("Hello from KinCony A32 Pro!");



  // Wait for a short period

  delay(100);



  // Check if data is available to read from RS485

  if (rs485Serial.available()) {

    String receivedMessage = "";

    while (rs485Serial.available()) {

      char c = rs485Serial.read();

      receivedMessage += c;

    }

    

    // Print the received message to the serial monitor

    Serial.print("Received: ");

    Serial.println(receivedMessage);

    

    // Echo the received message back over RS485

    rs485Serial.print("Echo: ");

    rs485Serial.println(receivedMessage);

  }



  // Wait before sending the next message

  delay(2000);

}