How can I use QextSerialPort on two different serial ports in the same time?

[inger]

In my program I want to communicate with two different com ports. From one of them I get alarm signals. This works Ok.
But now I try to send and receive data to a GSM terminal for sending SMS messages. I am not able to get response from the terminal to my computer.
Do you know if I can use QextSerialPort to communicate with several serial ports in the same program? I use QWidget as base.

[Lesiok]

Yes, You can create many instances of QExtSerialPort as You need.

[inger]

I still do not get any answer from com port number two(GSMcomm). My code is like:
The constructor:

EikeTesten::EikeTesten(QWidget *parent) :
    QWidget(parent)
{ ....
qDebug("Creating QextSerialPort instance");
    CommPort = new QextSerialPort();
    CommPort->setPortName(QString("/dev/ttyUSB0"));
    CommPort->setDataBits(DATA_8);
    CommPort->setParity(PAR_NONE);
    CommPort->setFlowControl(FLOW_OFF);
    CommPort->setStopBits(STOP_1);
    CommPort->setBaudRate(BAUD300);
    CommPort->open();
QTimer *receiveTimer = new QTimer(this);
    connect(receiveTimer, SIGNAL(timeout()), SLOT(receiveMsg())); // receiveMsg get the message from ttyUSB0 and call saveData();
    receiveTimer->start(0);
..
}

EikeTesten::EikeTesten(QWidget *parent) :
    QWidget(parent)
{ ....
qDebug("Creating QextSerialPort instance");
    CommPort = new QextSerialPort();
    CommPort->setPortName(QString("/dev/ttyUSB0"));
    CommPort->setDataBits(DATA_8);
    CommPort->setParity(PAR_NONE);
    CommPort->setFlowControl(FLOW_OFF);
    CommPort->setStopBits(STOP_1);
    CommPort->setBaudRate(BAUD300);
    CommPort->open();
QTimer *receiveTimer = new QTimer(this);
    connect(receiveTimer, SIGNAL(timeout()), SLOT(receiveMsg())); // receiveMsg get the message from ttyUSB0 and call saveData();
    receiveTimer->start(0);
..
}

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in saveData:

{  ....
GSMcomm = new GSMkommunikasjon();
     GSMcomm -> sendAlarmSMS(text);
....}

{  ....
GSMcomm = new GSMkommunikasjon();
     GSMcomm -> sendAlarmSMS(text);
....}

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in GSMkommunikasjon constructor:

{/*create and init communications port*/
    qDebug("Creating SMSCommPort instance");
    SMSCommPort = new QextSerialPort();
    SMSCommPort->setPortName(QString("/dev/ttyUSB1"));
    SMSCommPort->setDataBits(DATA_8);
    SMSCommPort->setParity(PAR_NONE);
    SMSCommPort->setFlowControl(FLOW_OFF);
    SMSCommPort->setStopBits(STOP_1);
    SMSCommPort->setBaudRate(BAUD19200);
    SMSCommPort->open();
    SMSCommPort->setDtr(0);
    SMSCommPort->setDtr(1);
    //SMSCommPort->close();
    //sendAlarmSMS();
 
    QTimer *receiveTimer2 = new QTimer(this);
    connect(receiveTimer2, SIGNAL(timeout()), SLOT(receiveFromSMS()));
    receiveTimer2->start(0);
}
 
in receiveFromSMS()
{
int numBytes = SMSCommPort->bytesAvailable();
 if(numBytes > 0) 
    {
      if (numBytes > 80) numBytes = 80;      
      char buff[80];
      int i = SMSCommPort->readData(buff, numBytes);
      buff[numBytes] = '\0';   
      QChar byte0 = buff[0];
      QChar byte1 = buff[1];
}}
... // But the program never receive anything
}

{/*create and init communications port*/
    qDebug("Creating SMSCommPort instance");
    SMSCommPort = new QextSerialPort();
    SMSCommPort->setPortName(QString("/dev/ttyUSB1"));
    SMSCommPort->setDataBits(DATA_8);
    SMSCommPort->setParity(PAR_NONE);
    SMSCommPort->setFlowControl(FLOW_OFF);
    SMSCommPort->setStopBits(STOP_1);
    SMSCommPort->setBaudRate(BAUD19200);
    SMSCommPort->open();
    SMSCommPort->setDtr(0);
    SMSCommPort->setDtr(1);
    //SMSCommPort->close();
    //sendAlarmSMS();

    QTimer *receiveTimer2 = new QTimer(this);
    connect(receiveTimer2, SIGNAL(timeout()), SLOT(receiveFromSMS()));
    receiveTimer2->start(0);
}

in receiveFromSMS()
{
int numBytes = SMSCommPort->bytesAvailable();
 if(numBytes > 0) 
    {
      if (numBytes > 80) numBytes = 80;      
      char buff[80];
      int i = SMSCommPort->readData(buff, numBytes);
      buff[numBytes] = '\0';   
      QChar byte0 = buff[0];
      QChar byte1 = buff[1];
}}
... // But the program never receive anything
}

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Can you please help me?

[marcvanriet]

Just the basic checks...
- is the baudrate correct
- if you have a scope or so, do you see the DTR line toggling when you open the port ?
- try to connect something else to that port and see if that works
- put a loopback wire on the port (connect RX and TXT) and then send something in your program. It should be received back

Regards,
Marc

[nix]

Hi,

Maybe it's not the matter, but it seems to me that you start 2 timers with a 0 interval time.
Is it correct? Your CPU should run at full charge, maybe that cause some trouble in the reception? Have you try with a reasonable time interval (250ms for instance)?

Loopback the wire can tell you if you're wrong on the protocol/in the serial configuration or if it's a software problem.

[inger]

Thank you for your feedback. I have tried to change the GSM terminal with something other, and then I got some input. The baudrate is correct. So something in my code is a little tricky.
I will check the timers