Qt Serial Port Baud Rate

4/12/2019
Posted by 

I have this problem with Qt whenever I try to set up a connection it never actually takes my data (e.g port name and baud rate) from the combo boxes and apparently it is because I do not link them very well. This is how I did it so far and, well, it doesn't work...

Qt Serial Port Baud Rate

Any suggestions?

Secondary question: Am I adding the items to the combo box correctly?

Joe Carr

Returns the serial number string of the serial port, if available; otherwise returns an empty string. Note: The serial number may include letters. This function was introduced in.

Joe CarrJoe Carr

1 Answer

QComboBox::currentData() return the QVariant which you provided when adding the currently selected item into the widget. To get the user data from your combobox selection as your serial port baud rate, use

zeFrenchyzeFrenchy

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/****************************************************************************
**
** Copyright (C) 2011-2012 Denis Shienkov <denis.shienkov@gmail.com>
** Copyright (C) 2011 Sergey Belyashov <Sergey.Belyashov@gmail.com>
** Copyright (C) 2012 Laszlo Papp <lpapp@kde.org>
** Copyright (C) 2012 Andre Hartmann <aha_1980@gmx.de>
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtSerialPort module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include'qserialport.h'
#include'qserialportinfo.h'
#include'qserialportinfo_p.h'
#include'qserialport_p.h'
#include<QtCore/qdebug.h>
QT_BEGIN_NAMESPACE
QSerialPortErrorInfo::QSerialPortErrorInfo(QSerialPort::SerialPortError newErrorCode,
const QString &newErrorString)
: errorCode(newErrorCode)
, errorString(newErrorString)
{
if (errorString.isNull()) {
switch (errorCode) {
case QSerialPort::NoError:
errorString = QSerialPort::tr('No error');
break;
case QSerialPort::OpenError:
errorString = QSerialPort::tr('Device is already open');
break;
case QSerialPort::NotOpenError:
errorString = QSerialPort::tr('Device is not open');
break;
case QSerialPort::TimeoutError:
errorString = QSerialPort::tr('Operation timed out');
break;
case QSerialPort::ReadError:
errorString = QSerialPort::tr('Error reading from device');
break;
case QSerialPort::WriteError:
errorString = QSerialPort::tr('Error writing to device');
break;
case QSerialPort::ResourceError:
errorString = QSerialPort::tr('Device disappeared from the system');
break;
default:
// an empty string will be interpreted as 'Unknown error'
// from the QIODevice::errorString()
break;
}
}
}
QSerialPortPrivate::QSerialPortPrivate()
#if defined(Q_OS_WIN32)
: readChunkBuffer(QSERIALPORT_BUFFERSIZE, 0)
#endif
{
writeBufferChunkSize = QSERIALPORT_BUFFERSIZE;
readBufferChunkSize = QSERIALPORT_BUFFERSIZE;
}
voidQSerialPortPrivate::setError(const QSerialPortErrorInfo &errorInfo)
{
Q_Q(QSerialPort);
error = errorInfo.errorCode;
q->setErrorString(errorInfo.errorString);
emit q->errorOccurred(error);
emit q->error(error);
}
/*!
class QSerialPort
brief Provides functions to access serial ports.
reentrant
ingroup serialport-main
inmodule QtSerialPort
since 5.1
You can get information about the available serial ports using the
QSerialPortInfo helper class, which allows an enumeration of all the serial
ports in the system. This is useful to obtain the correct name of the
serial port you want to use. You can pass an object
of the helper class as an argument to the setPort() or setPortName()
methods to assign the desired serial device.
After setting the port, you can open it in read-only (r/o), write-only
(w/o), or read-write (r/w) mode using the open() method.
note The serial port is always opened with exclusive access
(that is, no other process or thread can access an already opened serial port).
Use the close() method to close the port and cancel the I/O operations.
Having successfully opened, QSerialPort tries to determine the current
configuration of the port and initializes itself. You can reconfigure the
port to the desired setting using the setBaudRate(), setDataBits(),
setParity(), setStopBits(), and setFlowControl() methods.
There are a couple of properties to work with the pinout signals namely:
QSerialPort::dataTerminalReady, QSerialPort::requestToSend. It is also
possible to use the pinoutSignals() method to query the current pinout
signals set.
Once you know that the ports are ready to read or write, you can
use the read() or write() methods. Alternatively the
readLine() and readAll() convenience methods can also be invoked.
If not all the data is read at once, the remaining data will
be available for later as new incoming data is appended to the
QSerialPort's internal read buffer. You can limit the size of the read
buffer using setReadBufferSize().
QSerialPort provides a set of functions that suspend the
calling thread until certain signals are emitted. These functions
can be used to implement blocking serial ports:
list
li waitForReadyRead() blocks calls until new data is available for
reading.
li waitForBytesWritten() blocks calls until one payload of data has
been written to the serial port.
endlist
See the following example:
code
int numRead = 0, numReadTotal = 0;
char buffer[50];
for (;;) {
numRead = serial.read(buffer, 50);
// Do whatever with the array
numReadTotal += numRead;
if (numRead 0 && !serial.waitForReadyRead())
break;
}
endcode
If l{QIODevice::}{waitForReadyRead()} returns c false, the
connection has been closed or an error has occurred.
If an error occurs at any point in time, QSerialPort will emit the
errorOccurred() signal. You can also call error() to find the type of
error that occurred last.
Programming with a blocking serial port is radically different from
programming with a non-blocking serial port. A blocking serial port
does not require an event loop and typically leads to simpler code.
However, in a GUI application, blocking serial port should only be
used in non-GUI threads, to avoid freezing the user interface.
For more details about these approaches, refer to the
l {Qt Serial Port Examples}{example} applications.
The QSerialPort class can also be used with QTextStream and QDataStream's
stream operators (operator<<() and operator>>()). There is one issue to be
aware of, though: make sure that enough data is available before attempting
to read by using the operator>>() overloaded operator.
sa QSerialPortInfo
*/
/*!
enum QSerialPort::Direction
This enum describes the possible directions of the data transmission.
note This enumeration is used for setting the baud rate of the device
separately for each direction on some operating systems (for example,
POSIX-like).
value Input Input direction.
value Output Output direction.
value AllDirections Simultaneously in two directions.
*/
/*!
enum QSerialPort::BaudRate
This enum describes the baud rate which the communication device operates
with.
note Only the most common standard baud rates are listed in this enum.
value Baud1200 1200 baud.
value Baud2400 2400 baud.
value Baud4800 4800 baud.
value Baud9600 9600 baud.
value Baud19200 19200 baud.
value Baud38400 38400 baud.
value Baud57600 57600 baud.
value Baud115200 115200 baud.
value UnknownBaud Unknown baud. This value is obsolete. It is provided to
keep old source code working. We strongly advise against
using it in new code.
sa QSerialPort::baudRate
*/
/*!
enum QSerialPort::DataBits
This enum describes the number of data bits used.
value Data5 The number of data bits in each character is 5. It
is used for Baudot code. It generally only makes
sense with older equipment such as teleprinters.
value Data6 The number of data bits in each character is 6. It
is rarely used.
value Data7 The number of data bits in each character is 7. It
is used for true ASCII. It generally only makes
sense with older equipment such as teleprinters.
value Data8 The number of data bits in each character is 8. It
is used for most kinds of data, as this size matches
the size of a byte. It is almost universally used in
newer applications.
value UnknownDataBits Unknown number of bits. This value is obsolete. It
is provided to keep old source code working. We
strongly advise against using it in new code.
sa QSerialPort::dataBits
*/
/*!
enum QSerialPort::Parity
This enum describes the parity scheme used.
value NoParity No parity bit it sent. This is the most common
parity setting. Error detection is handled by the
communication protocol.
value EvenParity The number of 1 bits in each character, including
the parity bit, is always even.
value OddParity The number of 1 bits in each character, including
the parity bit, is always odd. It ensures that at
least one state transition occurs in each character.
value SpaceParity Space parity. The parity bit is sent in the space
signal condition. It does not provide error
detection information.
value MarkParity Mark parity. The parity bit is always set to the
mark signal condition (logical 1). It does not
provide error detection information.
value UnknownParity Unknown parity. This value is obsolete. It is
provided to keep old source code working. We
strongly advise against using it in new code.
sa QSerialPort::parity
*/
/*!
enum QSerialPort::StopBits
This enum describes the number of stop bits used.
value OneStop 1 stop bit.
value OneAndHalfStop 1.5 stop bits. This is only for the Windows platform.
value TwoStop 2 stop bits.
value UnknownStopBits Unknown number of stop bits. This value is obsolete.
It is provided to keep old source code working. We
strongly advise against using it in new code.
sa QSerialPort::stopBits
*/
/*!
enum QSerialPort::FlowControl
This enum describes the flow control used.
value NoFlowControl No flow control.
value HardwareControl Hardware flow control (RTS/CTS).
value SoftwareControl Software flow control (XON/XOFF).
value UnknownFlowControl Unknown flow control. This value is obsolete. It
is provided to keep old source code working. We
strongly advise against using it in new code.
sa QSerialPort::flowControl
*/
/*!
enum QSerialPort::PinoutSignal
This enum describes the possible RS-232 pinout signals.
value NoSignal No line active
value TransmittedDataSignal TxD (Transmitted Data). This value is
obsolete. It is provided to keep old
source code working. We strongly
advise against using it in new code.
value ReceivedDataSignal RxD (Received Data). This value is
obsolete. It is provided to keep old
source code working. We strongly
advise against using it in new code.
value DataTerminalReadySignal DTR (Data Terminal Ready).
value DataCarrierDetectSignal DCD (Data Carrier Detect).
value DataSetReadySignal DSR (Data Set Ready).
value RingIndicatorSignal RNG (Ring Indicator).
value RequestToSendSignal RTS (Request To Send).
value ClearToSendSignal CTS (Clear To Send).
value SecondaryTransmittedDataSignal STD (Secondary Transmitted Data).
value SecondaryReceivedDataSignal SRD (Secondary Received Data).
sa pinoutSignals(), QSerialPort::dataTerminalReady,
QSerialPort::requestToSend
*/
/*!
enum QSerialPort::DataErrorPolicy
obsolete
This enum describes the policies for the received symbols
while parity errors were detected.
value SkipPolicy Skips the bad character.
value PassZeroPolicy Replaces bad character with zero.
value IgnorePolicy Ignores the error for a bad character.
value StopReceivingPolicy Stops data reception on error.
value UnknownPolicy Unknown policy.
sa QSerialPort::dataErrorPolicy
*/
/*!
enum QSerialPort::SerialPortError
This enum describes the errors that may be contained by the
QSerialPort::error property.
value NoError No error occurred.
value DeviceNotFoundError An error occurred while attempting to
open an non-existing device.
value PermissionError An error occurred while attempting to
open an already opened device by another
process or a user not having enough permission
and credentials to open.
value OpenError An error occurred while attempting to open an
already opened device in this object.
value NotOpenError This error occurs when an operation is executed
that can only be successfully performed if the
device is open. This value was introduced in
QtSerialPort 5.2.
value ParityError Parity error detected by the hardware while
reading data. This value is obsolete. We strongly
advise against using it in new code.
value FramingError Framing error detected by the hardware while
reading data. This value is obsolete. We strongly
advise against using it in new code.
value BreakConditionError Break condition detected by the hardware on
the input line. This value is obsolete. We strongly
advise against using it in new code.
value WriteError An I/O error occurred while writing the data.
value ReadError An I/O error occurred while reading the data.
value ResourceError An I/O error occurred when a resource becomes
unavailable, e.g. when the device is
unexpectedly removed from the system.
value UnsupportedOperationError The requested device operation is not
supported or prohibited by the running operating
system.
value TimeoutError A timeout error occurred. This value was
introduced in QtSerialPort 5.2.
value UnknownError An unidentified error occurred.
sa QSerialPort::error
*/
/*!
Constructs a new serial port object with the given a parent.
*/
QSerialPort::QSerialPort(QObject *parent)
: QIODevice(*new QSerialPortPrivate, parent)
, d_dummy(0)
{
}
/*!
Constructs a new serial port object with the given a parent
to represent the serial port with the specified a name.
The name should have a specific format; see the setPort() method.
*/
QSerialPort::QSerialPort(const QString &name, QObject *parent)
: QIODevice(*new QSerialPortPrivate, parent)
, d_dummy(0)
{
setPortName(name);
}
/*!
Constructs a new serial port object with the given a parent
to represent the serial port with the specified helper class
a serialPortInfo.
*/
QSerialPort::QSerialPort(const QSerialPortInfo &serialPortInfo, QObject *parent)
: QIODevice(*new QSerialPortPrivate, parent)
, d_dummy(0)
{
setPort(serialPortInfo);
}
/*!
Closes the serial port, if necessary, and then destroys object.
*/
QSerialPort::~QSerialPort()
{
/**/
if (isOpen())
close();
}
/*!
Sets the a name of the serial port.
The name of the serial port can be passed as either a short name or
the long system location if necessary.
sa portName(), QSerialPortInfo
*/
voidQSerialPort::setPortName(const QString &name)
{
Q_D(QSerialPort);
d->systemLocation = QSerialPortInfoPrivate::portNameToSystemLocation(name);
}
/*!
Sets the port stored in the serial port info instance a serialPortInfo.
sa portName(), QSerialPortInfo
*/
voidQSerialPort::setPort(const QSerialPortInfo &serialPortInfo)
{
Q_D(QSerialPort);
d->systemLocation = serialPortInfo.systemLocation();
}
/*!
Returns the name set by setPort() or passed to the QSerialPort constructor.
This name is short, i.e. it is extracted and converted from the internal
variable system location of the device. The conversion algorithm is
platform specific:
table
header
li Platform
li Brief Description
row
li Windows
li Removes the prefix '.' or '//./' from the system location
and returns the remainder of the string.
row
li Unix, BSD
li Removes the prefix '/dev/' from the system location
and returns the remainder of the string.
endtable
sa setPort(), QSerialPortInfo::portName()
*/
QString QSerialPort::portName() const
{
Q_D(const QSerialPort);
returnQSerialPortInfoPrivate::portNameFromSystemLocation(d->systemLocation);
}
/*!
reimp
Opens the serial port using OpenMode a mode, and then returns c true if
successful; otherwise returns c false and sets an error code which can be
obtained by calling the error() method.
note The method returns c false if opening the port is successful, but could
not set any of the port settings successfully. In that case, the port is
closed automatically not to leave the port around with incorrect settings.
warning The a mode has to be QIODevice::ReadOnly, QIODevice::WriteOnly,
or QIODevice::ReadWrite. Other modes are unsupported.
sa QIODevice::OpenMode, setPort()
*/
boolQSerialPort::open(OpenMode mode)
{
Q_D(QSerialPort);
if (isOpen()) {
d->setError(QSerialPortErrorInfo(QSerialPort::OpenError));
returnfalse;
}
// Define while not supported modes.
staticconst OpenMode unsupportedModes = Append Truncate Text Unbuffered;
if ((mode & unsupportedModes) mode NotOpen) {
d->setError(QSerialPortErrorInfo(QSerialPort::UnsupportedOperationError, tr('Unsupported open mode')));
returnfalse;
}
clearError();
if (!d->open(mode))
returnfalse;
QIODevice::open(mode);
returntrue;
}
/*!
reimp
note The serial port has to be open before trying to close it; otherwise
sets the NotOpenError error code.
sa QIODevice::close()
*/
voidQSerialPort::close()
{
Q_D(QSerialPort);
if (!isOpen()) {
d->setError(QSerialPortErrorInfo(QSerialPort::NotOpenError));
return;
}
d->close();
d->isBreakEnabled = false;
QIODevice::close();
}
QT_WARNING_PUSH
QT_WARNING_DISABLE_DEPRECATED
#if QT_DEPRECATED_SINCE(5, 3)
/*!
property QSerialPort::settingsRestoredOnClose
brief the flag which specifies to restore the previous settings when closing
the serial port.
obsolete
If this flag is c true, the settings will be restored; otherwise not.
The default state of the QSerialPort class is to restore the
settings.
*/
voidQSerialPort::setSettingsRestoredOnClose(bool restore)
{
Q_D(QSerialPort);
if (d->settingsRestoredOnClose != restore) {
d->settingsRestoredOnClose = restore;
emit settingsRestoredOnCloseChanged(d->settingsRestoredOnClose);
}
}
QT_WARNING_POP
boolQSerialPort::settingsRestoredOnClose() const
{
Q_D(const QSerialPort);
return d->settingsRestoredOnClose;
}
#endif// QT_DEPRECATED_SINCE(5,3)
#if QT_DEPRECATED_SINCE(5, 5)
/*!
fn void QSerialPort::settingsRestoredOnCloseChanged(bool restore)
obsolete
This signal is emitted after the flag which specifies to restore the
previous settings while closing the serial port has been changed. The new
flag which specifies to restore the previous settings while closing the serial
port is passed as a restore.
sa QSerialPort::settingsRestoredOnClose
*/
#endif// QT_DEPRECATED_SINCE(5, 5)
/*!
property QSerialPort::baudRate
brief the data baud rate for the desired direction
If the setting is successful or set before opening the port, returns c true;
otherwise returns c false and sets an error code which can be obtained by
accessing the value of the QSerialPort::error property. To set the baud
rate, use the enumeration QSerialPort::BaudRate or any positive qint32
value.
note If the setting is set before opening the port, the actual serial port
setting is done automatically in the l{QSerialPort::open()} method right
after that the opening of the port succeeds.
warning Setting the AllDirections flag is supported on all platforms.
Windows supports only this mode.
warning Returns equal baud rate in any direction on Windows.
The default value is Baud9600, i.e. 9600 bits per second.
*/
boolQSerialPort::setBaudRate(qint32 baudRate, Directions directions)
{
Q_D(QSerialPort);
if (!isOpen() d->setBaudRate(baudRate, directions)) {
if (directions & QSerialPort::Input) {
if (d->inputBaudRate != baudRate)
d->inputBaudRate = baudRate;
else
directions &= ~QSerialPort::Input;
}
if (directions & QSerialPort::Output) {
if (d->outputBaudRate != baudRate)
d->outputBaudRate = baudRate;
else
directions &= ~QSerialPort::Output;
}
if (directions)
emit baudRateChanged(baudRate, directions);
returntrue;
}
returnfalse;
}
qint32 QSerialPort::baudRate(Directions directions) const
{
Q_D(const QSerialPort);
if (directions QSerialPort::AllDirections)
return d->inputBaudRate d->outputBaudRate ?
d->inputBaudRate : -1;
return directions & QSerialPort::Input ? d->inputBaudRate : d->outputBaudRate;
}
/*!
fn void QSerialPort::baudRateChanged(qint32 baudRate, Directions directions)
This signal is emitted after the baud rate has been changed. The new baud
rate is passed as a baudRate and directions as a directions.
sa QSerialPort::baudRate
*/
/*!
property QSerialPort::dataBits
brief the data bits in a frame
If the setting is successful or set before opening the port, returns
c true; otherwise returns c false and sets an error code which can be obtained
by accessing the value of the QSerialPort::error property.
note If the setting is set before opening the port, the actual serial port
setting is done automatically in the l{QSerialPort::open()} method right
after that the opening of the port succeeds.
The default value is Data8, i.e. 8 data bits.
*/
boolQSerialPort::setDataBits(DataBits dataBits)
{
Q_D(QSerialPort);
if (!isOpen() d->setDataBits(dataBits)) {
if (d->dataBits != dataBits) {
d->dataBits = dataBits;
emit dataBitsChanged(d->dataBits);
}
returntrue;
}
returnfalse;
}
QSerialPort::DataBits QSerialPort::dataBits() const
{
Q_D(const QSerialPort);
return d->dataBits;
}
/*!
fn void QSerialPort::dataBitsChanged(DataBits dataBits)
This signal is emitted after the data bits in a frame has been changed. The
new data bits in a frame is passed as a dataBits.
sa QSerialPort::dataBits
*/
/*!
property QSerialPort::parity
brief the parity checking mode
If the setting is successful or set before opening the port, returns c true;
otherwise returns c false and sets an error code which can be obtained by
accessing the value of the QSerialPort::error property.
note If the setting is set before opening the port, the actual serial port
setting is done automatically in the l{QSerialPort::open()} method right
after that the opening of the port succeeds.
The default value is NoParity, i.e. no parity.
*/
boolQSerialPort::setParity(Parity parity)
{
Q_D(QSerialPort);
if (!isOpen() d->setParity(parity)) {
if (d->parity != parity) {
d->parity = parity;
emit parityChanged(d->parity);
}
returntrue;
}
returnfalse;
}
QSerialPort::Parity QSerialPort::parity() const
{
Q_D(const QSerialPort);
return d->parity;
}
/*!
fn void QSerialPort::parityChanged(Parity parity)
This signal is emitted after the parity checking mode has been changed. The
new parity checking mode is passed as a parity.
sa QSerialPort::parity
*/
/*!
property QSerialPort::stopBits
brief the number of stop bits in a frame
If the setting is successful or set before opening the port, returns c true;
otherwise returns c false and sets an error code which can be obtained by
accessing the value of the QSerialPort::error property.
note If the setting is set before opening the port, the actual serial port
setting is done automatically in the l{QSerialPort::open()} method right
after that the opening of the port succeeds.
The default value is OneStop, i.e. 1 stop bit.
*/
boolQSerialPort::setStopBits(StopBits stopBits)
{
Q_D(QSerialPort);
if (!isOpen() d->setStopBits(stopBits)) {
if (d->stopBits != stopBits) {
d->stopBits = stopBits;
emit stopBitsChanged(d->stopBits);
}
returntrue;
}
returnfalse;
}
QSerialPort::StopBits QSerialPort::stopBits() const
{
Q_D(const QSerialPort);
return d->stopBits;
}
/*!
fn void QSerialPort::stopBitsChanged(StopBits stopBits)
This signal is emitted after the number of stop bits in a frame has been
changed. The new number of stop bits in a frame is passed as a stopBits.
sa QSerialPort::stopBits
*/
/*!
property QSerialPort::flowControl
brief the desired flow control mode
If the setting is successful or set before opening the port, returns c true;
otherwise returns c false and sets an error code which can be obtained by
accessing the value of the QSerialPort::error property.
note If the setting is set before opening the port, the actual serial port
setting is done automatically in the l{QSerialPort::open()} method right
after that the opening of the port succeeds.
The default value is NoFlowControl, i.e. no flow control.
*/
boolQSerialPort::setFlowControl(FlowControl flowControl)
{
Q_D(QSerialPort);
if (!isOpen() d->setFlowControl(flowControl)) {
if (d->flowControl != flowControl) {
d->flowControl = flowControl;
emit flowControlChanged(d->flowControl);
}
returntrue;
}
returnfalse;
}
QSerialPort::FlowControl QSerialPort::flowControl() const
{
Q_D(const QSerialPort);
return d->flowControl;
}
/*!
fn void QSerialPort::flowControlChanged(FlowControl flow)
This signal is emitted after the flow control mode has been changed. The
new flow control mode is passed as a flow.
sa QSerialPort::flowControl
*/
/*!
property QSerialPort::dataTerminalReady
brief the state (high or low) of the line signal DTR
Returns c true on success, c false otherwise.
If the flag is c true then the DTR signal is set to high; otherwise low.
note The serial port has to be open before trying to set or get this
property; otherwise c false is returned and the error code is set to
NotOpenError.
sa pinoutSignals()
*/
boolQSerialPort::setDataTerminalReady(bool set)
{
Q_D(QSerialPort);
if (!isOpen()) {
d->setError(QSerialPortErrorInfo(QSerialPort::NotOpenError));
qWarning('%s: device not open', Q_FUNC_INFO);
returnfalse;
}
constbool dataTerminalReady = isDataTerminalReady();
constbool retval = d->setDataTerminalReady(set);
if (retval && (dataTerminalReady != set))
emit dataTerminalReadyChanged(set);
return retval;
}
boolQSerialPort::isDataTerminalReady()
{
Q_D(QSerialPort);
return d->pinoutSignals() & QSerialPort::DataTerminalReadySignal;
}
/*!
fn void QSerialPort::dataTerminalReadyChanged(bool set)
This signal is emitted after the state (high or low) of the line signal DTR
has been changed. The new the state (high or low) of the line signal DTR is
passed as a set.
sa QSerialPort::dataTerminalReady
*/
/*!
property QSerialPort::requestToSend
brief the state (high or low) of the line signal RTS
Returns c true on success, c false otherwise.
If the flag is c true then the RTS signal is set to high; otherwise low.
note The serial port has to be open before trying to set or get this
property; otherwise c false is returned and the error code is set to
NotOpenError.
note An attempt to control the RTS signal in the HardwareControl mode
will fail with error code set to UnsupportedOperationError, because
the signal is automatically controlled by the driver.
sa pinoutSignals()
*/
boolQSerialPort::setRequestToSend(bool set)
{
Q_D(QSerialPort);
if (!isOpen()) {
d->setError(QSerialPortErrorInfo(QSerialPort::NotOpenError));
qWarning('%s: device not open', Q_FUNC_INFO);
returnfalse;
}
if (d->flowControl QSerialPort::HardwareControl) {
d->setError(QSerialPortErrorInfo(QSerialPort::UnsupportedOperationError));
returnfalse;
}
constbool requestToSend = isRequestToSend();
constbool retval = d->setRequestToSend(set);
if (retval && (requestToSend != set))
emit requestToSendChanged(set);
return retval;
}
boolQSerialPort::isRequestToSend()
{
Q_D(QSerialPort);
return d->pinoutSignals() & QSerialPort::RequestToSendSignal;
}
/*!
fn void QSerialPort::requestToSendChanged(bool set)
This signal is emitted after the state (high or low) of the line signal RTS
has been changed. The new the state (high or low) of the line signal RTS is
passed as a set.
sa QSerialPort::requestToSend
*/
/*!
Returns the state of the line signals in a bitmap format.
From this result, it is possible to allocate the state of the
desired signal by applying a mask 'AND', where the mask is
the desired enumeration value from QSerialPort::PinoutSignals.
note This method performs a system call, thus ensuring that the line signal
states are returned properly. This is necessary when the underlying
operating systems cannot provide proper notifications about the changes.
note The serial port has to be open before trying to get the pinout
signals; otherwise returns NoSignal and sets the NotOpenError error code.
sa QSerialPort::dataTerminalReady, QSerialPort::requestToSend
*/
QSerialPort::PinoutSignals QSerialPort::pinoutSignals()
{
Q_D(QSerialPort);
if (!isOpen()) {
d->setError(QSerialPortErrorInfo(QSerialPort::NotOpenError));
qWarning('%s: device not open', Q_FUNC_INFO);
return QSerialPort::NoSignal;
}
return d->pinoutSignals();
}
/*!
This function writes as much as possible from the internal write
buffer to the underlying serial port without blocking. If any data
was written, this function returns c true; otherwise returns c false.
Call this function for sending the buffered data immediately to the serial
port. The number of bytes successfully written depends on the operating
system. In most cases, this function does not need to be called, because the
QSerialPort class will start sending data automatically once control is
returned to the event loop. In the absence of an event loop, call
waitForBytesWritten() instead.
note The serial port has to be open before trying to flush any buffered
data; otherwise returns c false and sets the NotOpenError error code.
sa write(), waitForBytesWritten()
*/
boolQSerialPort::flush()
{
Q_D(QSerialPort);
if (!isOpen()) {
d->setError(QSerialPortErrorInfo(QSerialPort::NotOpenError));
qWarning('%s: device not open', Q_FUNC_INFO);
returnfalse;
}
return d->flush();
}
/*!
Discards all characters from the output or input buffer, depending on
given directions a directions. This includes clearing the internal class buffers and
the UART (driver) buffers. Also terminate pending read or write operations.
If successful, returns c true; otherwise returns c false.
note The serial port has to be open before trying to clear any buffered
data; otherwise returns c false and sets the NotOpenError error code.
*/
boolQSerialPort::clear(Directions directions)
{
Q_D(QSerialPort);
if (!isOpen()) {
d->setError(QSerialPortErrorInfo(QSerialPort::NotOpenError));
qWarning('%s: device not open', Q_FUNC_INFO);
returnfalse;
}
if (directions & Input)
d->buffer.clear();
if (directions & Output)
d->writeBuffer.clear();
return d->clear(directions);
}
/*!
reimp
Returns c true if no more data is currently available for reading; otherwise
returns c false.
This function is most commonly used when reading data from the
serial port in a loop. For example:
code
// This slot is connected to QSerialPort::readyRead()
void QSerialPortClass::readyReadSlot()
{
while (!port.atEnd()) {
QByteArray data = port.read(100);
....
}
}
endcode
sa bytesAvailable(), readyRead()
*/
boolQSerialPort::atEnd() const
{
returnQIODevice::atEnd();
}
#if QT_DEPRECATED_SINCE(5, 2)
/*!
property QSerialPort::dataErrorPolicy
brief the error policy for how the process receives characters in the case where
a parity error is detected.
obsolete
If the setting is successful, returns c true; otherwise returns c false. The
default policy set is IgnorePolicy.
note The serial port has to be open before trying to set this property;
otherwise returns c false and sets the NotOpenError error code. This is a bit
unusual as opposed to the regular Qt property settings of a class. However,
this is a special use case since the property is set through the interaction
with the kernel and hardware. Hence, the two scenarios cannot be completely
compared to each other.
*/
boolQSerialPort::setDataErrorPolicy(DataErrorPolicy policy)
{
Q_D(QSerialPort);
if (!isOpen()) {
d->setError(QSerialPortErrorInfo(QSerialPort::NotOpenError));
qWarning('%s: device not open', Q_FUNC_INFO);
returnfalse;
}
if (policy != QSerialPort::IgnorePolicy) {
d->setError(QSerialPortErrorInfo(QSerialPort::UnsupportedOperationError,
tr('The device supports only the ignoring policy')));
returnfalse;
}
returntrue;
}
QSerialPort::DataErrorPolicy QSerialPort::dataErrorPolicy() const
{
return QSerialPort::IgnorePolicy;
}
#endif// QT_DEPRECATED_SINCE(5, 2)
#if QT_DEPRECATED_SINCE(5, 5)
/*!
fn void QSerialPort::dataErrorPolicyChanged(DataErrorPolicy policy)
obsolete
This signal is emitted after the error policy for how the process receives
characters in case of parity error detection has been changed. The new error
policy for how the process receives the character in case of parity error
detection is passed as a policy.
sa QSerialPort::dataErrorPolicy
*/
#endif// QT_DEPRECATED_SINCE(5, 5)
/*!
property QSerialPort::error
brief the error status of the serial port
The I/O device status returns an error code. For example, if open()
returns c false, or a read/write operation returns c -1, this property can
be used to figure out the reason why the operation failed.
The error code is set to the default QSerialPort::NoError after a call to
clearError()
*/
QSerialPort::SerialPortError QSerialPort::error() const
{
Q_D(const QSerialPort);
return d->error;
}
voidQSerialPort::clearError()
{
Q_D(QSerialPort);
d->setError(QSerialPortErrorInfo(QSerialPort::NoError));
}
/*!
fn void QSerialPort::error(SerialPortError error)
obsolete
Use errorOccurred() instead.
*/
/*!
fn void QSerialPort::errorOccurred(SerialPortError error)
since 5.8
This signal is emitted when an error occurs in the serial port.
The specified a error describes the type of error that occurred.
sa QSerialPort::error
*/
/*!
Returns the size of the internal read buffer. This limits the
amount of data that the client can receive before calling the read()
or readAll() methods.
A read buffer size of c 0 (the default) means that the buffer has
no size limit, ensuring that no data is lost.
sa setReadBufferSize(), read()
*/
qint64 QSerialPort::readBufferSize() const
{
Q_D(const QSerialPort);
return d->readBufferMaxSize;
}
/*!
Sets the size of QSerialPort's internal read buffer to be a
size bytes.
If the buffer size is limited to a certain size, QSerialPort
will not buffer more than this size of data. The special case of a buffer
size of c 0 means that the read buffer is unlimited and all
incoming data is buffered. This is the default.
This option is useful if the data is only read at certain points
in time (for instance in a real-time streaming application) or if the serial
port should be protected against receiving too much data, which may
eventually cause the application to run out of memory.
sa readBufferSize(), read()
*/
voidQSerialPort::setReadBufferSize(qint64 size)
{
Q_D(QSerialPort);
d->readBufferMaxSize = size;
if (isReadable())
d->startAsyncRead();
}
/*!
reimp
Always returns c true. The serial port is a sequential device.
*/
boolQSerialPort::isSequential() const
{
returntrue;
}
/*!
reimp
Returns the number of incoming bytes that are waiting to be read.
sa bytesToWrite(), read()
*/
qint64 QSerialPort::bytesAvailable() const
{
returnQIODevice::bytesAvailable();
}
/*!
reimp
Returns the number of bytes that are waiting to be written. The
bytes are written when control goes back to the event loop or
when flush() is called.
sa bytesAvailable(), flush()
*/
qint64 QSerialPort::bytesToWrite() const
{
qint64 pendingBytes = QIODevice::bytesToWrite();
#if defined(Q_OS_WIN32)
pendingBytes += d_func()->writeChunkBuffer.size();
#endif
return pendingBytes;
}
/*!
reimp
Returns c true if a line of data can be read from the serial port;
otherwise returns c false.
sa readLine()
*/
boolQSerialPort::canReadLine() const
{
returnQIODevice::canReadLine();
}
/*!
reimp
This function blocks until new data is available for reading and the
l{QIODevice::}{readyRead()} signal has been emitted. The function
will timeout after a msecs milliseconds; the default timeout is
30000 milliseconds. If a msecs is -1, this function will not time out.
The function returns c true if the readyRead() signal is emitted and
there is new data available for reading; otherwise it returns c false
(if an error occurred or the operation timed out).
sa waitForBytesWritten()
*/
boolQSerialPort::waitForReadyRead(int msecs)
{
Q_D(QSerialPort);
return d->waitForReadyRead(msecs);
}
/*!
fn Handle QSerialPort::handle() const
since 5.2
If the platform is supported and the serial port is open, returns the native
serial port handle; otherwise returns c -1.
warning This function is for expert use only; use it at your own risk.
Furthermore, this function carries no compatibility promise between minor
Qt releases.
*/
/*!
reimp
This function blocks until at least one byte has been written to the serial
port and the l{QIODevice::}{bytesWritten()} signal has been emitted. The
function will timeout after a msecs milliseconds; the default timeout is
30000 milliseconds. If a msecs is -1, this function will not time out.
The function returns c true if the bytesWritten() signal is emitted; otherwise
it returns c false (if an error occurred or the operation timed out).
*/
boolQSerialPort::waitForBytesWritten(int msecs)
{
Q_D(QSerialPort);
return d->waitForBytesWritten(msecs);
}
#if QT_DEPRECATED_SINCE(5, 5)
/*!
Sends a continuous stream of zero bits during a specified period
of time a duration in msec if the terminal is using asynchronous
serial data. If successful, returns c true; otherwise returns c false.
If the duration is zero then zero bits are transmitted by at least
c 0.25 seconds, but no more than c 0.5 seconds.
If the duration is non zero then zero bits are transmitted within a certain
period of time depending on the implementation.
note The serial port has to be open before trying to send a break
duration; otherwise returns c false and sets the NotOpenError error code.
sa setBreakEnabled()
*/
boolQSerialPort::sendBreak(int duration)
{
Q_D(QSerialPort);
if (!isOpen()) {
d->setError(QSerialPortErrorInfo(QSerialPort::NotOpenError));
qWarning('%s: device not open', Q_FUNC_INFO);
returnfalse;
}
return d->sendBreak(duration);
}
#endif// QT_DEPRECATED_SINCE(5, 5)
/*!
property QSerialPort::breakEnabled
since 5.5
brief the state of the transmission line in break
Returns c true on success, c false otherwise.
If the flag is c true then the transmission line is in break state;
otherwise is in non-break state.
note The serial port has to be open before trying to set or get this
property; otherwise returns c false and sets the NotOpenError error code.
This is a bit unusual as opposed to the regular Qt property settings of
a class. However, this is a special use case since the property is set
through the interaction with the kernel and hardware. Hence, the two
scenarios cannot be completely compared to each other.
*/
boolQSerialPort::setBreakEnabled(bool set)
{
Q_D(QSerialPort);
if (!isOpen()) {
d->setError(QSerialPortErrorInfo(QSerialPort::NotOpenError));
qWarning('%s: device not open', Q_FUNC_INFO);
returnfalse;
}
if (d->setBreakEnabled(set)) {
if (d->isBreakEnabled != set) {
d->isBreakEnabled = set;
emit breakEnabledChanged(d->isBreakEnabled);
}
returntrue;
}
returnfalse;
}
boolQSerialPort::isBreakEnabled() const
{
Q_D(const QSerialPort);
return d->isBreakEnabled;
}
/*!
reimp
*/
// This function does not really read anything, as we use QIODevicePrivate's
// buffer. The buffer will be read inside of QIODevice before this
// method will be called.
qint64 QSerialPort::readData(char *data, qint64 maxSize)
{
Q_UNUSED(data);
Q_UNUSED(maxSize);
// In any case we need to start the notifications if they were
// disabled by the read handler. If enabled, next call does nothing.
d_func()->startAsyncRead();
// return 0 indicating there may be more data in the future
returnqint64(0);
}
/*!
reimp
*/
qint64 QSerialPort::readLineData(char *data, qint64 maxSize)
{
returnQIODevice::readLineData(data, maxSize);
}
/*!
reimp
*/
qint64 QSerialPort::writeData(constchar *data, qint64 maxSize)
{
Q_D(QSerialPort);
return d->writeData(data, maxSize);
}
#include'moc_qserialport.cpp'
QT_END_NAMESPACE

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