Serial port

shirisha

hi sir,

int nreturn=0,len;
char buf[5];
QString str,s;

QChar ch;

while (TRUE)
{

nreturn = read(fd,&buf,1);

str =buf[i];

len = str.length();

qDebug () << "no of bytes:" << len;

for( i=0;i<len;i++)
{

ch = str.at(i);

n+=ch.unicode();

s = QString::number(n,16);

}
qDebug () << "Data:" << s;

}

Am able to display hex value, when data is only one byte and other problem is when continusly data is read only first byte is getting correct remaing am geting addition of the previous data . if i read 5 bytes of data am getting junk data .Please help me

KushalAusula

use this

@QString a="a";
QByteArray BA1=a.toUtf8();
QByteArray BA2=BA1.toHex();
const char* chArr1=BA2.constData();
qDebug()<<QString::fromUtf8(chArr1);@

McLion

Is your fd the serialport?
Again, as asked before, why are you not using QSerialPort?
What is your target, the task you need to get done?

KushalAusula

Basic serial port usage as I have worked on is

@ serial=new QSerialPort(this);

serial->setPortName("/dev/ttyS0");
serial->setBaudRate(9600);
serial->setDataBits(QSerialPort::Data8);
serial->setParity(QSerialPort::NoParity);
serial->setFlowControl(QSerialPort::NoFlowControl);


serial->open(QIODevice::ReadWrite);

serial->write("Hello World");

connect(serial,SIGNAL(readyRead()),this,SLOT(readSerialData()));@

McLion

.. and the readSerialData() ... (pseudo code)
@
void QTGUI_MainWindow::readSerialData()
{
while((iBytesAvailable = serial->bytesAvailable()))
{
QByteArray RawPortData = serial->read(iBytesAvailable);
...

@

shirisha

int main(int argc, char *argv[])
{

QCoreApplication a(argc, argv);
fd = open(MODEMDEVICE,O_RDWR|O_NOCTTY);

While(true)

{
Buffer.clear();
nreturn = read(fd,&chBuf,1);
if(nreturn > 0)
{
for(i=0;i<nreturn;i++)
{
Buffer.append(chBuf[i]);

if(chBuf[0] == 0xc9) nReadIndex = 0;

pData[nReadIndex++] = chBuf[i];

qDebug() << "data" << Buffer.toHex();
}
if(chBuf[0] == 0xcf)
{

if(nReadIndex >= 10)

//Display of Gui opreration //

nReadIndex = 0;

}

For this how can i use timers instead of while loop, where should i start timer , i tried but am geting segmentation problem.Please help me

McLion

Your issue seems not to be about the serial port. Please open a new thread for a new topic.

btw: You seem to be very reluctant in using QSerialPort.

shirisha

k .

shirisha

Hi sir,

How to flush the data in serial port without using qextserialport

Please help me sir...

shirisha

hi sir...,
When i use Baud rate B115200...am getting segmentation fault ..in qt...How would i solve the problem..Please help me...

shirisha

hi sir...,
When i use Baud rate B115200...am getting segmentation fault ..in qt...How would i solve the problem..Please help me...

SGaist

Without any proper code, I can't.

SGaist

Without any proper code, I can't.

shirisha

#define BAUDRATE B9600

shirisha

#define BAUDRATE B9600

SGaist

That won't really help debugging but from the looks of it, you are using the linux platform API, so please ask this on a linux dedicated forum.

There's also this "how to":http://www.tldp.org/HOWTO/Serial-Programming-HOWTO/x115.html that should give you some hints and this "stack overflow post":http://stackoverflow.com/questions/6947413/how-to-open-read-and-write-from-serial-port-in-c

SGaist

That won't really help debugging but from the looks of it, you are using the linux platform API, so please ask this on a linux dedicated forum.

There's also this "how to":http://www.tldp.org/HOWTO/Serial-Programming-HOWTO/x115.html that should give you some hints and this "stack overflow post":http://stackoverflow.com/questions/6947413/how-to-open-read-and-write-from-serial-port-in-c