C++ Serial Communication Issue

Question

I am trying to make a Console C++ program that will be able to communicate through the serial port with my Arduino microcontroller, however I am having a problem with the ReadFile() function:

This is the ReadFile() function code from my C++ Console Program:

            if(ReadFile(myPortHandle, &szBuf, 1, &dwIncommingReadSize, NULL) != 0)
            {
                cout<<"FOUND IT!"<<endl;
                Sleep(100);
            }
            else
            {
                cout<<".";
                Sleep(100);
            }

The ReadFile function is consistently returning the "False" value, meaning it is not finding anything in the serial port. On the other side of the serial port, I have my Arduino Hooked up with the following code:

int switchPin = 4;                       // Switch connected to pin 4

void setup() {
  pinMode(switchPin, INPUT);             // Set pin 0 as an input
  Serial.begin(9600);                    // Start serial communication at 9600 bps
}

void loop() {
  if (digitalRead(switchPin) == HIGH) {  // If switch is ON,
    Serial.write(1);               // send 1 to Processing
  } else {                               // If the switch is not ON,
    Serial.write(0);               // send 0 to Processing
  }
  delay(100);                            // Wait 100 milliseconds
}

And every time I press a push button, I would send a "1" value to the serial port, and a "0" every time I don't press a push button. Basically, I got the Arduino code from a tutorial I watched on how to do serial communication with the program Processing (which worked perfectly), though I am unable to do the same with a simple Console Application I made with C++ because for some reason the ReadFile() function isn't finding any information in the serial port.

Anyone happen to know why?

PS: The complete code in the C++ Console Program can be found here: https://stackoverflow.com/questions/27844956/c-console-program-serial-communication-arduino

Answer 1

The ReadFile function is consistently returning the "False" value, meaning it is not finding anything

No, that is not what it means. A FALSE return value indicates that it failed . That is never normal, you must implement error reporting code so you can diagnose the reason. And end the program since there is little reason to continue running. Unless you setup the serial port to intentionally fail by setting a read timeout.

Use GetLastError() to obtain the underlying Windows error code.

Answer 2

您希望使用MS Windows，因此请先尝试使用portmon捕获arduino输出，然后再调试C ++代码。