我想从 115200,n,8,1 处的 COM1 读取(最好是阻塞调用,但我可以添加它。而且我不需要线程)。
我能找到的唯一代码是在 this question 中的 Stack Overflow 上(微软也有 some useful info )。
作者说他的代码有效,我不怀疑他,但是当我运行代码时我没有收到任何字符,即使端口正确打开(如果我用终端程序检查,数据是正在发送)。
有人可以发布一些示例 C 代码的 URL 吗?谢谢。
FWIW,这是我的代码:
// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
E_boolean OpenCom1(void)
{
COMMTIMEOUTS timeouts;
comPorthandle = CreateFile("COM1", // Specify port device: default "COM1"
GENERIC_READ | GENERIC_WRITE, // Specify mode that open device.
0, // the device isn't shared.
NULL, // the object gets a default security.
OPEN_EXISTING, // Specify which action to take on file.
0, // default (not overlapped i/o).
NULL); // default (hTemplate must be NULL for COM devices).
if (comPorthandle == INVALID_HANDLE_VALUE)
return False;
deviceControlBlock.DCBlength = sizeof(deviceControlBlock);
if((GetCommState(comPorthandle, &deviceControlBlock) == 0))
{
// CodeMe: do what?
return False;
}
deviceControlBlock.BaudRate = CBR_115200;
deviceControlBlock.StopBits = ONESTOPBIT;
deviceControlBlock.Parity = NOPARITY;
deviceControlBlock.ByteSize = DATABITS_8;
deviceControlBlock.fRtsControl = 0;
if (!SetCommState(comPorthandle, &deviceControlBlock))
{
// CodeMe: do what?
return False;
}
#if 0
// alternative to GetCommState() and SetCommState()
// both versions succeed
if (!BuildCommDCB("115200,n,8,1", &deviceControlBlock))
{
// CodeMe: do what?
return False;
}
#endif
// set short timeouts on the comm port.
timeouts.ReadIntervalTimeout = 0;
timeouts.ReadTotalTimeoutMultiplier = 1;
timeouts.ReadTotalTimeoutConstant = 1;
timeouts.WriteTotalTimeoutMultiplier = 1;
timeouts.WriteTotalTimeoutConstant = 1;
if (!SetCommTimeouts(comPorthandle, &timeouts))
{
// CodeMe: do what?
return False;
}
return True;
}//OpenCom1()
// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
void ReadCharacterFromCom1(INPUT char *theCharacter)
{
DWORD numBytesRead;
numBytesRead = 0;
while (numBytesRead == 0)
{
ReadFile(comPorthandle, // handle of file to read
theCharacter, // store read data here
sizeof(theCharacter), // number of bytes to read
&numBytesRead, // pointer to number of bytes actually read
NULL);
}
return;
}//ReadCharacterFromCom1()
最佳答案
我在这段代码中看到一个问题:
sizeof(theCharacter),
替换为
sizeof(char),
因为你要读取一个字节,而sizeof(char*)是4或8。可能还有别的东西,但你需要显示更多代码。
此外,使用 Portmon 程序 http://technet.microsoft.com/en-us/sysinternals/bb896644.aspx查看是否收到数据 - 您可以将其与您的程序一起运行。
关于c - 求串口读取例子,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15082447/