Win32 API串口编程
通常windows下串口编程大家会选择MFC使用SCOM控件进行串口操作，
方便而且简单，我也是这样的，PC端要进行串口编程就选择MFC做一个
简单的界面，添加SCOM控件。但有时我们需要在Win32下进行串口编程，
根据我在网上查的资料以及编程调试经验做一个简单的例子，需要深入的
可以此为基础。
串口编程的过程基本是这样的：
串口打开、串口读操作、串口写操作、串口关闭
包含头文件：
#include <windows.h>
#include <stdio.h>
一、串口的同步方式(等待操作完成后才能返回)：
1、 打开串口—同步方式
HANDLE Open_driver_T(char *name)
{
//打开串口
HANDLE m_hCom = CreateFile(name,GENERIC_READ | GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, 0, NULL);
if(m_hCom == INVALID_HANDLE_VALUE)
{
printf("Create File faile\n");
return NULL;
}
//设置缓冲区大小
if(!SetupComm(m_hCom,1024,1024))
{
printf("SetupComm fail!\n");
CloseHandle(m_hCom);
return NULL;
}
//设置超时
COMMTIMEOUTS TimeOuts;
memset(&TimeOuts,0,sizeof(TimeOuts));
TimeOuts.ReadIntervalTimeout = 100;
TimeOuts.ReadTotalTimeoutConstant = 1000;
TimeOuts.ReadTotalTimeoutMultiplier = 100;
TimeOuts.WriteTotalTimeoutConstant = 2000;
TimeOuts.WriteTotalTimeoutMultiplier = 50;
SetCommTimeouts(m_hCom,&TimeOuts);
PurgeComm(m_hCom,PURGE_TXCLEAR|PURGE_RXCLEAR);
//设置串口参数
DCB dcb = {0};
if (!GetCommState(m_hCom,&dcb))
{
printf("GetCommState fail\n");
return NULL;
}
dcb.DCBlength = sizeof(dcb);
if (!BuildCommDCB("1228800,n,8,1",&dcb))//填充ＤＣＢ的数据传输率、奇偶校验类型、数据位、停止位
{
printf("BuileCOmmDCB fail\n");
CloseHandle(m_hCom);
return NULL;
}
if(SetCommState(m_hCom,&dcb))
{
printf("SetCommState OK!\n");
}
return m_hCom;
}
2、串口发送(写操作)--同步方式
unsigned char Send_driver_T(HANDLE fd, BYTE *data)
{
DWORD dwError;
DWORD dwExpectSend = 20;
DWORD dwRealSend = 0;
BYTE *pSendBuffer;
pSendBuffer = data;
if(ClearCommError(fd,&dwError,NULL))
{
PurgeComm(fd,PURGE_TXABORT | PURGE_TXCLEAR);
}
if(!WriteFile(fd,pSendBuffer,dwExpectSend ,&dwRealSend,NULL))
{
//写串口失败
printf("发送失败!\n");
return 1;
}
return 0;
}
3、串口读取(读操作)--同步方式
unsigned char Receive_driver_T(HANDLE fd, BYTE *data)
{
DWORD dwError;
DWORD dwWantRead = 20;
DWORD dwRealRead = 0;
BYTE* pReadBuf;
int i;
BYTE crc;
pReadBuf = data;
if (ClearCommError(fd,&dwError,NULL))
{
PurgeComm(fd,PURGE_TXABORT | PURGE_TXCLEAR);
}
if(!ReadFile(fd,pReadBuf,dwWantRead ,&dwRealRead,NULL)) //成功返回非0 //失败返回0
{
return 1;
}
if(dwRealRead>0)
printf("recv_len = %d\n",dwRealRead);
printf("接收数据: ");
for(i=0; i<20; i++)
{
printf("%x ",data[i]);
}
printf("\n");
return 0;
}
4、串口关闭
int Close_driver(void *fd)
{
CloseHandle(fd);
return 0;
}
5、编程应用程序
void main()
{
HANDLE hCom;
BYTE SendData[20] = {0};
BYTE RecvData[100] = {0};
unsigned int SendCnt=0;
unsigned int RecvCnt=0;
int i;
hCom = Open_driver_T("COM3");
if(!hCom)
{
printf("串口端口打开失败\n");
return ;
}
else
printf("串口端口打开成功!\n");
SendCnt=0;
for(i=0; i<5; i++)
{
SendCnt++;
if(Send_driver_T(hCom, SendData))
{
printf("数据(%4d) 发送失败!\n",SendCnt);
}
else
{
printf("数据(%4d) 发送成功!\n",SendCnt);
}
Sleep(1000);
}
printf("\n");
RecvCnt=0;
for(i=0; i<5; i++)
{
if(Receive_driver_T(hCom, RecvData))
{
printf("数据(%4d) 接收失败!\n",RecvCnt);
}
else
{
RecvCnt++;
printf("数据(%4d) 接收成功!\n",RecvCnt);
}
Sleep(1000);
}
}
二、串口的异步方式(操作结束立即返回)
1、打开串口—异步方式
HANDLE Open_driver_Y(char *name)
{
//打开串口
HANDLE m_hCom = CreateFile(name,GENERIC_READ | GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
if(m_hCom == INVALID_HANDLE_VALUE)
{
printf("Create File faile\n");
return NULL;
}
//设置缓冲区大小
if(!SetupComm(m_hCom,1024,1024))
{
printf("SetupComm fail!\n");
CloseHandle(m_hCom);
return NULL;
}
//设置超时
COMMTIMEOUTS TimeOuts;
memset(&TimeOuts,0,sizeof(TimeOuts));
TimeOuts.ReadIntervalTimeout = 100;
TimeOuts.ReadTotalTimeoutConstant = 1000;
TimeOuts.ReadTotalTimeoutMultiplier = 100;
TimeOuts.WriteTotalTimeoutConstant = 2000;
TimeOuts.WriteTotalTimeoutMultiplier = 50;
SetCommTimeouts(m_hCom,&TimeOuts);
PurgeComm(m_hCom,PURGE_TXCLEAR|PURGE_RXCLEAR);
//设置串口参数
DCB dcb = {0};
if (!GetCommState(m_hCom,&dcb))
{
printf("GetCommState fail\n");
return NULL;
}
dcb.DCBlength = sizeof(dcb);
if (!BuildCommDCB("1228800,n,8,1",&dcb))//填充ＤＣＢ的数据传输率、奇偶校验类型、数据位、停止位
{
printf("BuileCOmmDCB fail\n");
CloseHandle(m_hCom);
return NULL;
}
if(SetCommState(m_hCom,&dcb))
{
printf("SetCommState OK!\n");
}
//建立并初始化重叠结构
ZeroMemory(&wrOverlapped,sizeof(wrOverlapped));
if (wrOverlapped.hEvent != NULL)
{
ResetEvent(wrOverlapped.hEvent);
wrOverlapped.hEvent = CreateEvent(NULL,TRUE,FALSE,NULL);
}
return m_hCom;
}
2、 串口发送(写操作)—异步方式
unsigned char Send_driver_Y(HANDLE fd, BYTE *data)
{
DWORD dwError;
DWORD dwExpectSend = 20;
DWORD dwRealSend = 0;
BYTE *pSendBuffer;
pSendBuffer = data;
if(ClearCommError(fd,&dwError,NULL))
{
PurgeComm(fd,PURGE_TXABORT | PURGE_TXCLEAR);
}
if(!WriteFile(fd,pSendBuffer,dwExpectSend ,&dwRealSend,&wrOverlapped))
{
if(GetLastError() == ERROR_IO_PENDING)
{
while(!GetOverlappedResult(fd,&wrOverlapped,&dwRealSend,FALSE))
//成功返回非0，失败返回0
{
if(GetLastError() == ERROR_IO_INCOMPLETE)
{
continue;
}
else
{
printf("发送失败!\n");
ClearCommError(fd,&dwError,NULL);
break;
return 1;
}
}
}
}
return 0;
}
3、 串口接收(读操作)--异步方式
unsigned char Receive_driver_Y(HANDLE fd, BYTE *data)
{
DWORD dwError;
DWORD dwWantRead = 20;
DWORD dwRealRead = 0;
BYTE* pReadBuf;
int i;
BYTE crc;
pReadBuf = data;
if (ClearCommError(fd,&dwError,NULL))
{
PurgeComm(fd,PURGE_TXABORT | PURGE_TXCLEAR);
}
if(!ReadFile(fd,pReadBuf,dwWantRead,&dwRealRead,&wrOverlapped))
{
dwError=GetLastError();
if(dwError == ERROR_IO_PENDING)
{
while(!GetOverlappedResult(fd,&wrOverlapped,&dwRealRead,TRUE))
//成功返回非0, 失败返回0
{
return 1;
}
}
}
if(dwRealRead>0)
printf("recv_len = %d\n",dwRealRead);
printf("接收数据\n");
for(i=0; i<20; i++)
{
printf("%x ",data[i]);
}
return 0;
}
4、 关闭串口
int Close_driver(void *fd)
{
CloseHandle(fd);
return 0;
}
5、 编程应用程序--异步方式
OVERLAPPED wrOverlapped;
void main()
{
HANDLE hCom;
BYTE SendData[20] = {0};
BYTE RecvData[100] = {0};
unsigned int SendCnt=0;
unsigned int RecvCnt=0;
int i;
hCom = Open_driver_Y("COM3");
if(!hCom)
{
printf("串口端口打开失败\n");
return ;
}
else
printf("串口端口打开成功!\n");
SendCnt=0;
for(i=0; i<5; i++)
{
SendCnt++;
if(Send_driver_Y(hCom, SendData))
{
printf("数据(%4d) 发送失败!\n",SendCnt);
}
else
{
printf("数据(%4d) 发送成功!\n",SendCnt);
}
Sleep(1000);
}
printf("\n");
RecvCnt=0;
for(i=0; i<5; i++)
{
if(Receive_driver_Y(hCom, RecvData))
{
printf("数据(%4d) 接收失败!\n",RecvCnt);
}
else
{
RecvCnt++;
printf("数据(%4d) 接收成功!\n",RecvCnt);
}
Sleep(1000);
}
}
相关函数原型以及参数定义请参考MSDN