带有Arduino的C ++中的串行通信超时

Question

The code below is what I am using to send and receive information from my Arduino. My problem is when the Arduino is first plugged in. Reading from it hangs because the command doesn't return anything because there is nothing there yet so my whole program crashes. How can I add a time-out to the read function, which is arduino->ReadLine(); , that causes the issue? That way will it keep going after a second?

#include "stdafx.h"
#include <iostream>

using namespace System;
using namespace System::IO::Ports;

int main(int argc, char* argv[])
{
    using namespace std;

    String^ portName;
    int baudRate=9600;

    portName="COM4";
    // Arduino settings.
    SerialPort^ arduino;

    arduino = gcnew SerialPort(portName, baudRate);
    // Open port.
    try
    {
        arduino->Open();
        {
            if (strcmp(argv[1],"-send")==0) {
                String^ command = gcnew String(reinterpret_cast<const char*>(argv[2]));
                if (String::Compare(command,"int6")==0) {
                    arduino->Write("^");
                }
                else
                    arduino->Write(command);
            }
            if(strcmp(argv[1],"-get")==0) {
                String^ command = gcnew String(reinterpret_cast<const char*>(argv[2]));
                arduino->WriteLine(command);
                String^ result = arduino->ReadLine();
                Console::Write(result);
            }
        }

Answer 1

设置arduino->ReadTimeout = duration_in_ms ，然后捕获TimeoutException 。

Answer 2

In addition to the timeout your code should loop until the BytesToRead property of the SerialPort is greater than zero

while (arduino->BytesToRead==0) {}

You could keep track of how long you have looped and exit gracefully with a user message if there is nothing received from the arduino within the expected time frame.