c語言的串口數據

① C語言變成實現串口收發數據

#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; // 定時器1工作於8位自動重載模式, 用於產生波特率

TH1 = 0xFD; // 波特率9600

TL1 = 0xFD;

SCON = 0x50; // 設定串列口工作方式

PCON &= 0xef; // 波特率不倍增

TR1 = 1; // 啟動定時器1

IE = 0x0; // 禁止任何中斷

while(1)

{

if(scan_key()) // 掃描按鍵

{

delayms(10); // 延時去抖動

if(scan_key()) // 再次掃描

{

key_v = key_s; // 保存鍵值

proc_key(); // 鍵處理

}

}

if(RI) // 是否有數據到來

{

RI = 0;

tmp = SBUF; // 暫存接收到的數據

P0 = tmp; // 數據傳送到P0口

send_char(tmp); // 回傳接收到的數據

}

}

}

bit scan_key()

// 掃描按鍵

｛

key_s = 0x00;

key_s |= K1;

return(key_s ^ key_v);

}

void proc_key()

// 鍵處理

{

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

{ // K1按下

send_str(); // 傳送字串"welcome!...

}

}

void send_char(unsigned char txd)

// 傳送一個字元

{

SBUF = txd;

while(!TI); // 等特數據傳送

TI = 0; // 清除數據傳送標志

}

void send_str()

// 傳送字串

{

unsigned char i = 0;

while(str[i] != '')

{

SBUF = str[i];

while(!TI); // 等特數據傳送

TI = 0; // 清除數據傳送標志

i++; // 下一個字元

}

}

void delayms(unsigned char ms)

// 延時子程序

{

unsigned char i;

while(ms--)

{

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

}

}

拓展資料

C語言是一門通用計算機編程語言，應用廣泛。C語言的設計目標是提供一種能以簡易的方式編譯、處理低級存儲器、產生少量的機器碼以及不需要任何運行環境支持便能運行的編程語言。

盡管C語言提供了許多低級處理的功能，但仍然保持著良好跨平台的特性，以一個標准規格寫出的C語言程序可在許多電腦平台上進行編譯，甚至包含一些嵌入式處理器（單片機或稱MCU）以及超級電腦等作業平台。

二十世紀八十年代，為了避免各開發廠商用的C語言語法產生差異，由美國國家標准局為C語言制定了一套完整的美國國家標准語法，稱為ANSI C，作為C語言最初的標准。目前2011年12月8日，國際標准化組織（ISO）和國際電工委員會（IEC）發布的C11標準是C語言的第三個官方標准，也是C語言的最新標准，該標准更好的支持了漢字函數名和漢字標識符，一定程度上實現了漢字編程。

② 用C語言讀取串口數據

調用輸入輸出的函數,它的參數大概是埠地址和緩沖區（好像是哈，TC2.0里是有的，好像是input，其它版本的C也應該有類似的函數）——跟windows裡面的deviceiocontrol（）很類似的，
調用它就可以啦
當然你要先把串口設置好，比如波特率之類的

③ 如何用C語言控制計算機串口

基本方法是使用CreateFile來建立一個串口文件，然後用overlap的方式進行讀寫

#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);// 發送數據
int ComConnect(CString strPort); // 連接COM口
HANDLE OpenComPort(CString strPort, int nBaudRate, int nDataBits, int nStopBits, int nParity, int nFlowCtrlType); // 打開串口
void Close(); // 關閉串口

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

PFN_CMD_PARSE_DATA m_pRspCmdFunc; // 用來處理接受數據的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()
{
}
//打開串口通信，並返回串口句柄
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口的文件名應該是 \\.\COMXX

//打開窗口其實就是創建一個文件
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;

// 設置一些COM口通訊參數和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;
}
}

// 這個線程是監視串口數據，一旦有數據則讀取並調用CALLBACK通知客戶端
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下怎麼用C語言讀取串口裡的數據

Windows下的語言讀取串口的數據，可以通過USB的一些特定連接。

⑤ 怎樣在WINDOWS下用C語言編寫串口接收數據程序

#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，好久沒看了，不知到對不對。
還有下面這段：
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#include
#include
HANDLE
hCom;
int
main(void)
{
hCom=CreateFile(TEXT("COM3"),//COM1口
GENERIC_READ|GENERIC_WRITE,
//允許讀和寫
0,
//獨占方式
NULL,
OPEN_EXISTING,
//打開而不是創建
0,
//同步方式
NULL);
if(hCom==(HANDLE)-1)
{
printf("打開COM失敗!\n");
return
FALSE;
}
else
{
printf("COM打開成功！\n");
}
SetupComm(hCom,1024,1024);
//輸入緩沖區和輸出緩沖區的大小都是1024
COMMTIMEOUTS
TimeOuts;
//設定讀超時
TimeOuts.ReadIntervalTimeout=1000;
TimeOuts.ReadTotalTimeoutMultiplier=500;
TimeOuts.ReadTotalTimeoutConstant=5000;
//設定寫超時
TimeOuts.WriteTotalTimeoutMultiplier=500;
TimeOuts.WriteTotalTimeoutConstant=2000;
SetCommTimeouts(hCom,&TimeOuts);
//設置超時
DCB
dcb;
GetCommState(hCom,&dcb);
dcb.BaudRate=9600;
//波特率為9600
dcb.ByteSize=8;
//每個位元組有8位
dcb.Parity=NOPARITY;
//無奇偶校驗位
dcb.StopBits=ONE5STOPBITS;
//兩個停止位
SetCommState(hCom,&dcb);
DWORD
wCount;//讀取的位元組數
BOOL
bReadStat;
while(1)
{
PurgeComm(hCom,PURGE_TXCLEAR|PURGE_RXCLEAR);
//清空緩沖區
char
str[9]={0};
printf("%s\n",str);
bReadStat=ReadFile(hCom,str,9,&wCount,NULL);
if(!bReadStat)
{
printf("讀串口失敗!");
return
FALSE;
}
else
{
str[8]='\0';
printf("%s\n",str);
}
Sleep(100);
}
}
以上兩段代碼是一年前弄的，我記得可以用，你試試。