Serial port

kuzulis

Did you read Wiki? What version of Qt do you use?

Please paste more informative messages, how you tried?

shirisha

hi sir,

@
QChar chbuf[50];
QString ReadData;
nSerialreturn = read(fd,chbuf,50);
qDebug () << "Timer running:"<< nSerialreturn;
for(i = 0;i<nSerialreturn;i++)
{
ReadData = chbuf[i];
qDebug () << "Data:" << ReadData;
}
@

am unable to get the data..and data should be in hexadecimal ..unable to convert it ..please help me sir

[edit: added missing coding tags @ SGaist]

SGaist

Please answer the questions we are asking you in order for us to help you.

Again, it seems that you are not using QSerialPort, if so, then go to the appropriate forum like I already suggested.

Otherwise, tell us exactly what version of Qt you are using. Show us the code where you initialize QSerialPort. Tell us what parameter your serial port should use.

shirisha

hi sir,
am using qt 4.8.4

shirisha

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

here am getting decimal data..i would like to get hex value please help me

shirisha

QSerialPort. is done only in windows ,but i linux r what...in windows am able to get theat ,bt in linux am hving problem sir
..above menstined code am able to get the data in decimal..but i want in hex data ..please help me

SGaist

QSerialPort works on all support platform so what is your exact problem with linux ?

Most probably you don't have the rights to access the serial port, do you ?

McLion

"This thread":http://qt-project.org/forums/viewthread/44793/ will guide you through my experiences when I added it to 4.6.3.
If you follow all the posts, you should be able to successfully add QtSerialPort to 4.8.4 .. even easier because you may not need all the changes that were needed for 4.6.3.

shirisha

thank u sir..now serial port is working , but am not able to read the hex data from 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...