c语言的串口数据

① C语言变成实现串口收发数据

#include <reg51.h>

#include <intrins.h>

unsigned char key_s, key_v, tmp;

char code str[] = "welcome!www.willar.com ";

void send_str();

bit scan_key();

void proc_key();

void delayms(unsigned char ms);

void send_char(unsigned char txd);

sbit K1 = P1^4;

main()

{

TMOD = 0x20; // 定时器1工作于8位自动重载模式, 用于产生波特率

TH1 = 0xFD; // 波特率9600

TL1 = 0xFD;

SCON = 0x50; // 设定串行口工作方式

PCON &= 0xef; // 波特率不倍增

TR1 = 1; // 启动定时器1

IE = 0x0; // 禁止任何中断

while(1)

{

if(scan_key()) // 扫描按键

{

delayms(10); // 延时去抖动

if(scan_key()) // 再次扫描

{

key_v = key_s; // 保存键值

proc_key(); // 键处理

}

}

if(RI) // 是否有数据到来

{

RI = 0;

tmp = SBUF; // 暂存接收到的数据

P0 = tmp; // 数据传送到P0口

send_char(tmp); // 回传接收到的数据

}

}

}

bit scan_key()

// 扫描按键

｛

key_s = 0x00;

key_s |= K1;

return(key_s ^ key_v);

}

void proc_key()

// 键处理

{

if((key_v & 0x01) == 0)

{ // K1按下

send_str(); // 传送字串"welcome!...

}

}

void send_char(unsigned char txd)

// 传送一个字符

{

SBUF = txd;

while(!TI); // 等特数据传送

TI = 0; // 清除数据传送标志

}

void send_str()

// 传送字串

{

unsigned char i = 0;

while(str[i] != '')

{

SBUF = str[i];

while(!TI); // 等特数据传送

TI = 0; // 清除数据传送标志

i++; // 下一个字符

}

}

void delayms(unsigned char ms)

// 延时子程序

{

unsigned char i;

while(ms--)

{

for(i = 0; i < 120; i++);

}

}

拓展资料

C语言是一门通用计算机编程语言，应用广泛。C语言的设计目标是提供一种能以简易的方式编译、处理低级存储器、产生少量的机器码以及不需要任何运行环境支持便能运行的编程语言。

尽管C语言提供了许多低级处理的功能，但仍然保持着良好跨平台的特性，以一个标准规格写出的C语言程序可在许多电脑平台上进行编译，甚至包含一些嵌入式处理器（单片机或称MCU）以及超级电脑等作业平台。

二十世纪八十年代，为了避免各开发厂商用的C语言语法产生差异，由美国国家标准局为C语言制定了一套完整的美国国家标准语法，称为ANSI C，作为C语言最初的标准。目前2011年12月8日，国际标准化组织（ISO）和国际电工委员会（IEC）发布的C11标准是C语言的第三个官方标准，也是C语言的最新标准，该标准更好的支持了汉字函数名和汉字标识符，一定程度上实现了汉字编程。

② 用C语言读取串口数据

调用输入输出的函数,它的参数大概是端口地址和缓冲区（好像是哈，TC2.0里是有的，好像是input，其它版本的C也应该有类似的函数）——跟windows里面的deviceiocontrol（）很类似的，
调用它就可以啦
当然你要先把串口设置好，比如波特率之类的

③ 如何用C语言控制计算机串口

基本方法是使用CreateFile来建立一个串口文件，然后用overlap的方式进行读写

#define SERAIL_PORT_BUF_MAX (1024*8)
typedef HRESULT (*PFN_CMD_PARSE_DATA)(HANDLE hParseApp, LPCSTR szRspCmd, int nCmdLen);

class CUsbSrvApp// : public CWinApp
{
public:
CUsbSrvApp();
~CUsbSrvApp();
BOOL OnSendData(const char *szBuf, int nLen);// 发送数据
int ComConnect(CString strPort); // 连接COM口
HANDLE OpenComPort(CString strPort, int nBaudRate, int nDataBits, int nStopBits, int nParity, int nFlowCtrlType); // 打开串口
void Close(); // 关闭串口

HANDLE m_hCom;
BOOL m_bConnected;
OVERLAPPED m_OverlappedRead;
OVERLAPPED m_OverlappedWrite;
CWinThread *m_pThread;

PFN_CMD_PARSE_DATA m_pRspCmdFunc; // 用来处理接受数据的CALLBACK
HANDLE m_hParseApp;
};

CUsbSrvApp::CUsbSrvApp()
{
// TODO: add construction code here,
// Place all significant initialization in InitInstance
m_bConnected = false;
m_hCom = NULL;
m_pRspCmdFunc = NULL;
}

CUsbSrvApp::~CUsbSrvApp()
{
}
//打开串口通信，并返回串口句柄
HANDLE CUsbSrvApp::OpenComPort(CString strPortName,
int nBaudRate,
int nDataBits,
int nStopBits,
int nParity,
int nFlowCtrlType)
{
DCB dcb;
COMMTIMEOUTS CommTimeOuts ;
COMMCONFIG ComConfig;
HANDLE hComPort;

CString strPort;
strPort.Format("\\\\.\\%s",strPortName); // COM口的文件名应该是 \\.\COMXX

//打开窗口其实就是创建一个文件
hComPort = CreateFile(strPort,
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL|FILE_FLAG_OVERLAPPED,
NULL);

if (INVALID_HANDLE_VALUE == hComPort)
return INVALID_HANDLE_VALUE;

// 设置一些COM口通讯参数和OVERLAP
CommTimeOuts.ReadIntervalTimeout = -1;
CommTimeOuts.ReadTotalTimeoutConstant = 0;
CommTimeOuts.ReadTotalTimeoutMultiplier = 0;
CommTimeOuts.WriteTotalTimeoutConstant = 0;
CommTimeOuts.WriteTotalTimeoutMultiplier = 0x1388;
SetCommTimeouts( m_hCom, &CommTimeOuts ) ;

SetDefaultCommConfig(strPortName, &ComConfig, sizeof(COMMCONFIG));
GetCommState(m_hCom, &dcb ) ;

dcb.BaudRate = nBaudRate;
dcb.ByteSize = nDataBits;
dcb.StopBits = nStopBits;
dcb.fParity = (NOPARITY != nParity);
dcb.Parity = nParity;
//set the receive char
dcb.EvtChar = 0x0D;

switch(nFlowCtrlType)
{
case 0: //no flow control
break;

case 1://HARD_FLOW_CTRL:

dcb.fOutxCtsFlow = TRUE;
dcb.fOutxDsrFlow = TRUE;
dcb.fDtrControl = DTR_CONTROL_DISABLE;
dcb.fDsrSensitivity = TRUE;
dcb.fRtsControl = RTS_CONTROL_TOGGLE;
break;

case 2://SOFT_FLOW_CTRL:
dcb.fOutX = TRUE;
dcb.fInX = TRUE;
break;
}
BuildCommDCB(_T("baud=115200 parity=N data=8 stop=1"),&dcb);
SetCommState(hComPort, &dcb ) ;
SetCommMask(hComPort, 0);
SetCommMask(hComPort, EV_RXCHAR|EV_CTS|EV_DSR|EV_RLSD|EV_RING);
SetupComm( hComPort, SERAIL_PORT_BUF_MAX,SERAIL_PORT_BUF_MAX) ;
//clear read and write buffer
PurgeComm( hComPort, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR );

return hComPort;
}

void CUsbSrvApp::Close()
{
if(m_bConnected)
{
m_bConnected = false;
CloseHandle(m_hCom);
m_hCom = NULL;
}
}

// 这个线程是监视串口数据，一旦有数据则读取并调用CALLBACK通知客户端
UINT ReceiveComData(LPVOID pParam)
{
CUsbSrvApp *pUsbSrv = (CUsbSrvApp *)pParam;
HANDLE hComPort = pUsbSrv->m_hCom;

DWORD dwEvtMask=0;
DWORD dwErrorFlags;

SetCommMask( hComPort, EV_RXCHAR);
OVERLAPPED osRead;
osRead.hEvent = CreateEvent(NULL,FALSE,FALSE,NULL);
DWORD dwTransfer = 0;
while(pUsbSrv->m_bConnected)
{
if( !WaitCommEvent( hComPort, &dwEvtMask,&osRead))
{
if( GetLastError()== ERROR_IO_PENDING)
{
WaitForSingleObject(osRead.hEvent, INFINITE);
if(dwEvtMask&EV_RXCHAR==EV_RXCHAR)
{
COMSTAT ComStat={0} ;
DWORD dwReadLen = 0;
DWORD dwBytesRead = 0;
DWORD dwTotalLen = 0;
ClearCommError(hComPort, &dwErrorFlags, &ComStat );
dwTotalLen = ComStat.cbInQue;
dwReadLen = (SERAIL_PORT_BUF_MAX > dwTotalLen)?dwTotalLen:SERAIL_PORT_BUF_MAX;

BYTE *pBuf = new BYTE[dwTotalLen+1];
memset(pBuf, 0 , dwTotalLen+1);
DWORD nReadBufLen=0;
while(dwTotalLen>0)
{

if(FALSE == ReadFile( hComPort, pBuf+nReadBufLen,dwReadLen, &dwBytesRead,&pUsbSrv->m_OverlappedRead))
{
if(GetLastError() == ERROR_IO_PENDING)
{
GetOverlappedResult(hComPort,&osRead, &dwTransfer, TRUE );
}
break;
}

nReadBufLen +=dwBytesRead;
dwTotalLen -=dwBytesRead;
dwReadLen -= dwBytesRead;
dwReadLen = (SERAIL_PORT_BUF_MAX>dwReadLen)?dwReadLen:SERAIL_PORT_BUF_MAX;
}
if(pUsbSrv->m_pRspCmdFunc!=NULL&&nReadBufLen!=0)
{
pUsbSrv->m_pRspCmdFunc(pUsbSrv->m_hParseApp, (char*)pBuf,nReadBufLen);
}

delete pBuf;

ClearCommError(hComPort, &dwErrorFlags, &ComStat );
int len =0;//= m_retList.GetSize();
}//endif if(dwEvtMask&EV_RXCHAR==EV_RXCHAR)
}//endif if( GetLastError()== ERROR_IO_PENDING)
}//endif if( !WaitCommEvent( hComPort, &dwEvtMask,&o))
else
{
if(GetLastError() == ERROR_IO_PENDING) {
GetOverlappedResult(hComPort, &osRead, &dwTransfer, TRUE ); // sleep thread
}
}
Sleep(1);
} //endwhile while(m_bConnected)
return 0;
}

int CUsbSrvApp::ComConnect(CString strPort)
{
int nBaudRate = 115200;
int nDataBits = 8;
int nStopBits = 1;
int nParity = 0;
int nFlowCtrl = 1;

if (NULL != m_hCom || m_bConnected)
{
return 0;
}
m_hCom = OpenComPort(strPort,nBaudRate,nDataBits,nStopBits,nParity,nFlowCtrl);
if( INVALID_HANDLE_VALUE == m_hCom)
{
m_hCom = NULL;
return 0;
}
memset( &m_OverlappedRead, 0, sizeof( OVERLAPPED ) );
memset( &m_OverlappedWrite, 0, sizeof( OVERLAPPED ) );
m_OverlappedRead.hEvent = CreateEvent( NULL, TRUE, FALSE, NULL );
m_OverlappedWrite.hEvent = CreateEvent( NULL, TRUE, FALSE, NULL );

m_pThread = AfxBeginThread( ReceiveComData,(void*)this,THREAD_PRIORITY_NORMAL,0,CREATE_SUSPENDED ,NULL );

if( NULL == m_pThread )
{
CloseHandle( m_hCom );
m_hCom = NULL;
return FALSE;
}
else
{
m_bConnected = TRUE;
m_pThread->ResumeThread( );
}

return TRUE;
}

int CUsbSrvApp::OnSendData(const char *szBuf, int nLen)
{
BOOL bWriteStat;
BOOL bWrite = TRUE;
DWORD dwBytesWrite = 0;
DWORD dwBytesWritten = 0;
int dwByteswrittenTotal = 0;

if (NULL == m_hCom)
return 0;

int nSentTimes=0;

while(dwByteswrittenTotal<nLen&&nSentTimes<10)
{
nSentTimes++;
dwBytesWrite = nLen-dwByteswrittenTotal;
bWriteStat = WriteFile( m_hCom, szBuf+dwByteswrittenTotal, dwBytesWrite, &dwBytesWritten, &m_OverlappedWrite );

if( !bWriteStat)
{
if ( GetLastError() == ERROR_IO_PENDING )
{
dwBytesWritten = 0;
bWrite = FALSE;
}
}
if (!bWrite)
{
bWrite = TRUE;

bWriteStat = GetOverlappedResult(m_hCom, // Handle to COMM port
&m_OverlappedWrite, // Overlapped structure
&dwBytesWritten, // Stores number of bytes sent
TRUE); // Wait flag
//deal with the error code
}
dwByteswrittenTotal += dwBytesWritten;
}
if(dwByteswrittenTotal<nLen)
return 0;
else
return 1;
}

④ windows下怎么用C语言读取串口里的数据

Windows下的语言读取串口的数据，可以通过USB的一些特定连接。

⑤ 怎样在WINDOWS下用C语言编写串口接收数据程序

#include
#include
int
main(void)
{
FILE
*fp;
char
temp;
char
buf[100];
if((fp
=
fopen("com3","r"))
==
NULL)
puts("this
way
doesn't
work!\n");
else
puts("this
way
works!\n");
while(1)
{
temp
=
0;
fscanf(fp,"%c",&temp);
if(temp
!=
0)
putchar(temp);
else
Sleep(100);
}
fclose(fp);
return
0;
}
以前弄的，好久没看了，不知到对不对。
还有下面这段：
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#include
#include
HANDLE
hCom;
int
main(void)
{
hCom=CreateFile(TEXT("COM3"),//COM1口
GENERIC_READ|GENERIC_WRITE,
//允许读和写
0,
//独占方式
NULL,
OPEN_EXISTING,
//打开而不是创建
0,
//同步方式
NULL);
if(hCom==(HANDLE)-1)
{
printf("打开COM失败!\n");
return
FALSE;
}
else
{
printf("COM打开成功！\n");
}
SetupComm(hCom,1024,1024);
//输入缓冲区和输出缓冲区的大小都是1024
COMMTIMEOUTS
TimeOuts;
//设定读超时
TimeOuts.ReadIntervalTimeout=1000;
TimeOuts.ReadTotalTimeoutMultiplier=500;
TimeOuts.ReadTotalTimeoutConstant=5000;
//设定写超时
TimeOuts.WriteTotalTimeoutMultiplier=500;
TimeOuts.WriteTotalTimeoutConstant=2000;
SetCommTimeouts(hCom,&TimeOuts);
//设置超时
DCB
dcb;
GetCommState(hCom,&dcb);
dcb.BaudRate=9600;
//波特率为9600
dcb.ByteSize=8;
//每个字节有8位
dcb.Parity=NOPARITY;
//无奇偶校验位
dcb.StopBits=ONE5STOPBITS;
//两个停止位
SetCommState(hCom,&dcb);
DWORD
wCount;//读取的字节数
BOOL
bReadStat;
while(1)
{
PurgeComm(hCom,PURGE_TXCLEAR|PURGE_RXCLEAR);
//清空缓冲区
char
str[9]={0};
printf("%s\n",str);
bReadStat=ReadFile(hCom,str,9,&wCount,NULL);
if(!bReadStat)
{
printf("读串口失败!");
return
FALSE;
}
else
{
str[8]='\0';
printf("%s\n",str);
}
Sleep(100);
}
}
以上两段代码是一年前弄的，我记得可以用，你试试。