ofSerial - Windows does not detect disconnections or errors in connection.

If you plug in an Arduino, initialize the serial port, and then go and manually disconnect the Arduino's USB cable, then ofSerial will not detect an error in the connection if you try to read bytes (readByte or readBytes).

This is a known issue: http://stackoverflow.com/questions/20713207/identify-disconnect-event-with-a-windows-usb-virtual-com-port

So, since I'm working on a project in which disconnections are frequent, I coded a little function to know if the connection is healthy, it is only coded for windows, but will do a OSX Linux version now and will do a pull request.

This function needs for baud to be stored as an attribute, so there will be few changes in some other functions and in the header file.

bool ofSerial::getConnectionStatus(){

if(bInited){

COMMCONFIG cfg;
DWORD cfgSize;
char  buf[80];

cfgSize=sizeof(cfg);
GetCommConfig(hComm,&cfg,&cfgSize);

int bps = this->baud;
sprintf(buf,"baud=%d parity=N data=8 stop=1",bps);

#if (_MSC_VER)       // microsoft visual studio
    // msvc doesn't like BuildCommDCB,
    //so we need to use this version: BuildCommDCBA
    if(!BuildCommDCBA(buf,&cfg.dcb)){
        ofLogError("ofSerial") << "setup(): unable to build comm dcb, (" << buf << ")";
    }
#else
    if(!BuildCommDCB(buf,&cfg.dcb)){
        ofLogError("ofSerial") << "setup(): unable to build comm dcb, (" << buf << ")";
    }
#endif

if(!GetCommState(hComm, &cfg.dcb))
    return false;
if(!SetCommState(hComm, &cfg.dcb))
    return false;

//if execution passes both conditions, then the COM port is healthy
return true;

}
else{
    // not initialized so we return false
    return false;
}

}

Start at ofSerial and its header, then trace the readByte and readBytes paths involved after a device is disconnected. Review how the baud value is stored and use the proposed getConnectionStatus behavior as the reference; done means a disconnected Windows serial device is reported as unhealthy without breaking normal reads.