#include <SoftwareSerial.h>

#define SerialControl 7

#define RS485Tx HIGH
#define RS485Rx LOW


SoftwareSerial RS485Serial(11, 12);
uint8_t window[8]; // Initialising window of 8 bytes

byte SendKWh[] = { 0x01, 0x03, 0x40, 0x34, 0x00, 0x02, 0x90, 0x05 };

// 0x01: Meter Address, 0x03: Read Function Code, 0x40: Register Address Variable (Start address high bit)
// 0x34: Register Address Variable (Start address low bit)
// 0x00: Register Quantity (High Bit), 0x02: Register Quantity (Low Bit)
// 0x90: CRC check code (CRC code Low bit)
// 0x05: CRC check code (CRC code High bit)

void dumpWin() {
  for (int i = 0; i < 8; i++) {
    Serial.print(window[i], HEX);
    Serial.print(" ");
  }
Serial.println();
}

void ReadRx() {

  // Sliding Window Implementation for reading data

  if(RS485Serial.available()) {

    uint8_t b = RS485Serial.read();

    dumpWin();


      // Slide the contents of the array down
      for (uint8_t i = 0; i < 7; i++) {
          window[i] = window[i+1];
      }

      window[7] = b; // Next frame inserted at the top of previous

      if ((window[0] == 0x01) && (window[1] == 0x03) &&
          (window[2] == 0x40) && (window[3] == 0x34)) {

            // Doing something with window[4] and window[5] here
     }
    }
  }



void setup() {

  Serial.begin(115200);
  pinMode(SerialControl, OUTPUT);

  RS485Serial.begin(9600);

}

void loop() {

  static uint32_t ts = millis();

  if (millis() - ts >= 2000) {
    ts = millis();
    digitalWrite(SerialControl, RS485Tx);
    RS485Serial.write(SendKWh, sizeof(SendKWh));
    RS485Serial.flush();
    digitalWrite(SerialControl, RS485Rx);
    RS485Serial.listen();
  }

  ReadRx();
}

#include <SoftwareSerial.h>

#define SerialControl 7

#define RS485Tx HIGH
#define RS485Rx LOW


SoftwareSerial RS485Serial(11, 12);

byte SendKWh[] = { 0x01, 0x03, 0x40, 0x34, 0x00, 0x02, 0x90, 0x05 };

// 0x01: Meter Address, 0x03: Read Function Code, 0x40: Register Address Variable (Start address high bit)
// 0x34: Register Address Variable (Start address low bit)
// 0x00: Register Quantity (High Bit), 0x02: Register Quantity (Low Bit)
// 0x90: CRC check code (CRC code Low bit)
// 0x05: CRC check code (CRC code High bit)

uint8_t window[8]; // Initialising window of 8 bytes

void dumpWin() {
  for (int i = 0; i < 8; i++) {
    Serial.print(window[i], HEX);
    Serial.print(" ");
  }
  Serial.println();
}

void ReadRx() {
  if(RS485Serial.available()) {
    uint8_t b = RS485Serial.read();
    dumpWin();
    // Slide the contents of the array down
    for (uint8_t i = 0; i < 7; i++) {
      window[i] = window[i+1];
    }

    window[7] = b; // Next frame inserted at the top of previous

    if ((window[0] == 0x01) && (window[1] == 0x03) &&
        (window[2] == 0x40) && (window[3] == 0x34)) {
          // Doing something with window[4] and window[5] here
    }
  }
}



void setup() {
  Serial.begin(115200);
  pinMode(SerialControl, OUTPUT);
  digitalWrite(SerialControl, RS485Rx);
  RS485Serial.begin(9600);

}

void loop() {
  static uint32_t ts = millis();

  if (millis() - ts >= 2000) {
      ts = millis();
      digitalWrite(SerialControl, RS485Tx);
      RS485Serial.write(SendKWh, sizeof(SendKWh));
      RS485Serial.flush();
      digitalWrite(SerialControl, RS485Rx);
      RS485Serial.listen();
  }

  ReadRx();
}