This code connects to COM 3 which has a broadband card and sends a command that returns the RSSI value. I use this program to see patterns in signal strength in certain areas.#include <Windows.h>#include <iostream>#include <string>int main(){    HANDLE hSerial = CreateFile(COM3,GENERIC_READ | GENERIC_WRITE,0,0,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0);    if(hSerial==INVALID_HANDLE_VALUE)        std::cout << Insert error message;    DCB dcbSerialParams = {0};    dcbSerialParams.DCBlength=sizeof(dcbSerialParams);    if (!GetCommState(hSerial, &dcbSerialParams))         std::cout << Insert error message;    dcbSerialParams.BaudRate=CBR_9600;    dcbSerialParams.ByteSize=8;    dcbSerialParams.StopBits=ONESTOPBIT;    dcbSerialParams.Parity=NOPARITY;    if (!SetCommState(hSerial,&dcbSerialParams))        std::cout << Insert error message;    COMMTIMEOUTS timeouts={0};    timeouts.ReadIntervalTimeout=50;    timeouts.ReadTotalTimeoutConstant=50;    timeouts.ReadTotalTimeoutMultiplier=10;    timeouts.WriteTotalTimeoutConstant=50;    timeouts.WriteTotalTimeoutMultiplier=10;    if(!SetCommTimeouts(hSerial, &timeouts))        std::cout << Insert error message;    while(1)    {        char szBuff[50+1] = {0};        char wzBuff[14] = {AT+CSQ\r};        DWORD dZBytesRead = 0;        DWORD dwBytesRead = 0;        if(!WriteFile(hSerial, wzBuff, 7, &dZBytesRead, NULL))            std::cout << Write error;        if(!ReadFile(hSerial, szBuff, 50, &dwBytesRead, NULL))            std::cout << Read Error;        std::string subString = std::string(szBuff).substr(8,3);        std::cout << subString;        Sleep(500);    }    return 0;}
Serial port communication app
c++;windows;serial port