[英]writing and reading to/from a serial port with a timeout in c++ and Linux
I'm trying to send some hex string to a serial port, and directly read its answer in c++. 我正在尝试将一些十六进制字符串发送到串行端口,并直接在c ++中读取它的答案。 If there is no answer it should timeout after a given period of time.
如果没有答案,它应该在给定的一段时间后超时。
To be clear: I'm searching for the most simple way to achieve this. 要明确:我正在寻找实现这一目标的最简单方法。
Sorry if my question is dumb, but im new to this topic, thanks in advance! 对不起,如果我的问题是愚蠢的,但我是这个话题的新手,请提前感谢!
EDIT: Sorry that I forgot to mention, it should run on Linux. 编辑:对不起,我忘了提,它应该在Linux上运行。
this should be similar to your declaration: 这应该类似于你的声明:
Setup(CSerial::EBaud9600,CSerial::EData8,CSerial::EParNone,CSerial::EStop1);
Setup(CSerial::EBaudrate(9600),
CSerial::EDataBits(8),
CSerial::EParity(NOPARITY),
CSerial::EStopBits(ONESTOPBIT));
Reading data: 阅读数据:
// Read data, until there is nothing left
DWORD dwBytesRead = 0;
BYTE abBuffer[100];
do
{
// Read data from the COM-port
serial.Read(abBuffer,sizeof(abBuffer),&dwBytesRead);
if (dwBytesRead > 0)
{
// TODO: Process the data
}
}
while (dwBytesRead == sizeof(abBuffer));
More details can be found here on code project: http://www.codeproject.com/Articles/992/Serial-library-for-C 更多细节可以在代码项目中找到: http : //www.codeproject.com/Articles/992/Serial-library-for-C
Please note: I am used to programming serial ports in c#, and so (to the best of my knowledge) believe this would work for you. 请注意:我习惯用c#编写串口,所以(据我所知)相信这对你有用。 (I would also like to point outall serial port communication is send actually through as hex, but may be read via the buffer as a decimal value ( please refer to http://www.asciitable.com/ for converstion, or use something similar to UTF8 encoding)
(我还想指出所有串口通信实际上是以十六进制形式发送的,但可以通过缓冲区读取十进制值(请参考http://www.asciitable.com/进行转换,或者使用类似的东西)到UTF8编码)
EDIT - As per comment; 编辑 - 根据评论;
Please refer to : http://msdn.microsoft.com/en-gb/library/windows/hardware/hh439614(v=vs.85).aspx for details on serial port read/write timeouts 有关串行端口读/写超时的详细信息,请参阅: http : //msdn.microsoft.com/en-gb/library/windows/hardware/hh439614(v = vs.85).aspx
Write timeout will be similar to; 写超时将类似于;
[BrowsableAttribute(true)]
public:
property int WriteTimeout {
int get ();
void set (int value);
}
Which allows you to get or set the timeout attribute 这允许您获取或设置超时属性
Full Program 完整计划
public:
static void Main()
{
String^ name;
String^ message;
StringComparer^ stringComparer = StringComparer::OrdinalIgnoreCase;
Thread^ readThread = gcnew Thread(gcnew ThreadStart(PortChat::Read));
// Create a new SerialPort object with default settings.
_serialPort = gcnew SerialPort();
// Allow the user to set the appropriate properties.
_serialPort->PortName = SetPortName(_serialPort->PortName);
_serialPort->BaudRate = SetPortBaudRate(_serialPort->BaudRate);
_serialPort->Parity = SetPortParity(_serialPort->Parity);
_serialPort->DataBits = SetPortDataBits(_serialPort->DataBits);
_serialPort->StopBits = SetPortStopBits(_serialPort->StopBits);
_serialPort->Handshake = SetPortHandshake(_serialPort->Handshake);
// Set the read/write timeouts
_serialPort->ReadTimeout = 500;
_serialPort->WriteTimeout = 500;
_serialPort->Open();
_continue = true;
readThread->Start();
Console::Write("Name: ");
name = Console::ReadLine();
Console::WriteLine("Type QUIT to exit");
while (_continue)
{
message = Console::ReadLine();
if (stringComparer->Equals("quit", message))
{
_continue = false;
}
else
{
_serialPort->WriteLine(
String::Format("<{0}>: {1}", name, message) );
}
}
readThread->Join();
_serialPort->Close();
}
static void Read()
{
while (_continue)
{
try
{
String^ message = _serialPort->ReadLine();
Console::WriteLine(message);
}
catch (TimeoutException ^) { }
}
}
EDIT 2 编辑2
Please refer to Linux Serial Port: Blocking Read with Timeout where this has been declared in the question and some of the answers may prove useful to you as well! 请参阅Linux Serial Port:Blocking Read with Timeout ,其中已在问题中声明了这一点,并且一些答案也可能对您有用! :)
:)
I recently came for the same issue and I found a good solution using select() Read the documentation here: manpages.courirer-mta.org/htmlman2/select2.html 我最近遇到了同样的问题,我找到了一个很好的解决方案,使用select()阅读这里的文档:manpages.courirer-mta.org/htmlman2/select2.html
In your case you need to setup the timeout, which is the 5th argument of select: 在你的情况下,你需要设置超时,这是选择的第五个参数:
struct timeval timeout;
timeout.tv_sec = 0 ; // seconds
timeout.tv_usec = 1000 ; // microseconds
Hope this helps. 希望这可以帮助。
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