C++ отправка команд на ардуино через com порт посредством библиотеки windows.h

#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <cstdio>
#include <vector>
#include <set>
#include <queue>
#include <map>
#include <string>
#include <cmath>
#include <functional>
#include <algorithm>
#include <utility>
#include <stack>
#include <unordered_map>
#include <iterator>
#include <fstream>
#include <iomanip>
#include <windows.h>
 
using namespace std;
 
#define X real()
#define Y imag()
#define timer fghge
#define y1 yjyjyju
#define all(X) (X).begin(), (X).end()
#define int long long
#define double long double
 
signed main() {
    HANDLE hSerial;
    LPCTSTR sPortName = L"COM5";
    hSerial = ::CreateFile(sPortName, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
    if (hSerial == INVALID_HANDLE_VALUE){
        if (GetLastError() == ERROR_FILE_NOT_FOUND)
            cout << "serial port does not exist.\n";
        cout << "some other error occurred.\n";
    }
    DCB dcbSerialParams = { 0 };
    dcbSerialParams.DCBlength = sizeof(dcbSerialParams);
    if (!GetCommState(hSerial, &dcbSerialParams))
        cout << "getting state error\n";
    dcbSerialParams.BaudRate = CBR_9600;
    dcbSerialParams.ByteSize = 8;
    dcbSerialParams.StopBits = ONESTOPBIT;
    dcbSerialParams.Parity = NOPARITY;
    if (!SetCommState(hSerial, &dcbSerialParams))
        cout << "error setting serial port state\n";
   
    char data[] = "a";  // строка для передачи
    DWORD dwSize = sizeof(data);   // размер этой строки
    DWORD dwBytesWritten;    // тут будет количество собственно переданных байт
 
    BOOL iRet = WriteFile(hSerial, data, dwSize, &dwBytesWritten, NULL);
 
    cout << dwSize << " Bytes in string. " << dwBytesWritten << " Bytes sended. " << endl;
    CloseHandle(hSerial);
    return 0;
}

void setup() {
        Serial.begin(9600); // устанавливаем последовательное соединение
        pinMode(13, OUTPUT);
    }
 
 
    void loop() {
        if (Serial.available() > 0) {  //если есть доступные данные
            digitalWrite(13, HIGH);
        }
    }

#define _CRT_SECURE_NO_WARNINGS
#define _USE_MATH_DEFINES
#include <iostream>
#include <cstdio>
#include <vector>
#include <set>
#include <queue>
#include <map>
#include <string>
#include <cmath>
#include <functional>
#include <algorithm>
#include <utility>
#include <stack>
#include <unordered_map>
#include <iterator>
#include <fstream>
#include <iomanip>
#include <windows.h>
 
using namespace std;
 
#define X real()
#define Y imag()
#define timer fghge
#define y1 yjyjyju
#define all(X) (X).begin(), (X).end()
#define int long long
#define double long double
 
signed main() {
 
    HANDLE hComm;
    LPCTSTR sPortName = L"COM3";
    hComm = CreateFile(sPortName, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL); 
 
    if (hComm == INVALID_HANDLE_VALUE)
        printf("Error in opening serial port");
    else
        printf("opening serial port successful");
 
    DCB dcbSerialParams = { 0 }; // Initializing DCB structure
    dcbSerialParams.DCBlength = sizeof(dcbSerialParams);
 
    dcbSerialParams.BaudRate = CBR_9600;  // Setting BaudRate = 9600
    dcbSerialParams.ByteSize = 8;         // Setting ByteSize = 8
    dcbSerialParams.StopBits = ONESTOPBIT;// Setting StopBits = 1
    dcbSerialParams.Parity = NOPARITY;  // Setting Parity = None
 
    char lpBuffer[] = "A";
    DWORD dNoOFBytestoWrite;         // No of bytes to write into the port
    DWORD dNoOfBytesWritten = 0;     // No of bytes written to the port
    dNoOFBytestoWrite = sizeof(lpBuffer);
    Sleep(2000);
    WriteFile(hComm, lpBuffer, dNoOFBytestoWrite, &dNoOfBytesWritten, NULL);
    
    CloseHandle(hComm);
    return 0;
}