c – 使用WriteFile / ReadFile的Serial Comm

COMMTIMEOUTS timeouts;

timeouts.ReadIntervalTimeout = 1;
timeouts.Read@R_487_10586@lTimeoutMultiplier = 1;
timeouts.Read@R_487_10586@lTimeoutConstant = 1;
timeouts.Write@R_487_10586@lTimeoutMultiplier = 1;
timeouts.Write@R_487_10586@lTimeoutConstant = 1;
if (!SetCommTimeouts(m_hCommPort,&timeouts))
    // setTing timeouts Failed.

编辑：也许更容易从一些有效的代码开始,并使它做你想做的,而不是试图让你的代码工作.这是一个简单的终端程序.它极端极简,但确实有效(至少足以让我看到GPS的输出,例如).从任何人(最不重要的是我)称之为复杂的方面来说,这是一个漫长的道路,但至少应该给出一些如何开始的想法.

#include <stdio.h>
#include <conio.h>
#include <String.h>

#define StriCT
#define WIN32_LEAN_AND_MEAN
#include <windows.h>

void system_error(char *Name) {
// Retrieve,format,and print out a message from the last error.  The 
// `name' that's passed should be in the form of a present tense noun 
// (phrasE) such as "opening file".
//
    char *ptr = NULL;
    Formatmessage(
        FORMAT_messaGE_ALLOCATE_BUFFER |
        FORMAT_messaGE_FROM_SYstem,GetLastError(),(char *)&ptr,1024,null);

    fprintf(stderr,"\nError %s: %s\n",name,ptr);
    LocalFree(ptr);
}

int main(int argc,char **argv) {

    int ch;
    char buffer[1];
    HANDLE file;
    COMMTIMEOUTS timeouts;
    DWORD read,written;
    DCB port;
    HANDLE keyboard = GetStdHandle(STD_INPUT_HANDLE);
    HANDLE screen = GetStdHandle(STD_OUTPUT_HANDLE);
    DWORD mode;
    char port_name[128] = "\\\\.\\COM3";
    char init[] = ""; // e.g.,"ATZ" to completely reset a modem.

    if ( argc > 2 )
        sprintf(port_name,"\\\\.\\COM%c",argv[1][0]);

    // open the comm port.
    file = CreateFile(port_name,GENERIC_READ | GENERIC_WRITE,NULL,OPEN_EXISTinG,null);

    if ( INVALID_HANDLE_VALUE == filE) {
        system_error("opening file");
        return 1;
    }

    // get the current DCB,and adjust a few bits to our liking.
    memset(&port,sizeof(port));
    port.DCBlength = sizeof(port);
    if ( !GetCommState(file,&port))
        system_error("getTing comm state");
    if (!BuildCommDCB("baud=19200 parity=n data=8 stop=1",&port))
        system_error("building comm DCB");
    if (!SetCommState(file,&port))
        system_error("adjusTing port setTings");

    // set short timeouts on the comm port.
    timeouts.ReadIntervalTimeout = 1;
    timeouts.Read@R_487_10586@lTimeoutMultiplier = 1;
    timeouts.Read@R_487_10586@lTimeoutConstant = 1;
    timeouts.Write@R_487_10586@lTimeoutMultiplier = 1;
    timeouts.Write@R_487_10586@lTimeoutConstant = 1;
    if (!SetCommTimeouts(file,&timeouts))
        system_error("setTing port time-outs.");

    // set keyboard to raw reading.
    if (!GetConsoleMode(keyboard,&modE))
        system_error("getTing keyboard mode");
    mode &= ~ ENABLE_PROCESSED_INPUT;
    if (!SetConsoleMode(keyboard,modE))
        system_error("setTing keyboard mode");

    if (!EscapeCommFunction(file,CLRDTR))
        system_error("clearing DTR");
    Sleep(200);
    if (!EscapeCommFunction(file,SETDTR))
        system_error("setTing DTR");

    if ( !WriteFile(file,init,sizeof(init),&written,NULL))
        system_error("wriTing data to port");

    if (written != sizeof(init))
        system_error("not all data written to port");

    // basic terminal loop:
    do {
        // check for data on port and display it on screen.
        ReadFile(file,buffer,sizeof(buffer),&read,null);
        if ( read )
            WriteFile(screen,read,null);

        // check for keypress,and write any out the port.
        if ( kbhit() ) {
            ch = getch();
            WriteFile(file,&ch,1,null);
        }
    // until user hits ctrl-BACkspace.
    } while ( ch != 127);

    // close up and go home.
    CloseHandle(keyboard);
    CloseHandle(filE);
    return 0;
}