QT reading Serialport of Arduino
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Hi. all. i'm stuck in reading some string from arduino. The Serial Port didn't open automatically when I debug first time in QT. But when I open the serial monitor from Arduino IDE, then I close it, then I debug again in QT, then the arduino begin to send its string. But when I upload the code to arduino again, then I debug the QT, it didn't sent anything. It seems my arduino didn't open automatically of its serial port. How can I debug the QT without open the serial monitor from arduino ide in the first?
This is my simple code
//================ Arduino Code ============== void setup() { Serial.begin(9600); pinMode (led, OUTPUT); } void loop() { Serial.println ("test"); }and this is QT Code
SerialPortManager::SerialPortManager(QObject *parent) : QObject(parent) { arduino = new QSerialPort(this); connect(arduino, SIGNAL(readyRead()), this, SLOT(readData())); } void SerialPortManager::openSerialPort() { arduino->setPortName("COM8"); arduino->open(QIODevice::ReadWrite); arduino->setBaudRate(QSerialPort::Baud9600); arduino->setDataBits(QSerialPort::Data8); arduino->setParity(QSerialPort::NoParity); arduino->setStopBits(QSerialPort::OneStop); arduino->setFlowControl(QSerialPort::NoFlowControl); } void SerialPortManager::readData() { QByteArray data = arduino->readAll(); // console->putData(data); qDebug() << "UART:" << data; }@mimamrafi said in QT reading Serialport of Arduino:
void SerialPortManager::openSerialPort()
{
arduino->setPortName("COM8");
arduino->open(QIODevice::ReadWrite);
arduino->setBaudRate(QSerialPort::Baud9600);
arduino->setDataBits(QSerialPort::Data8);
arduino->setParity(QSerialPort::NoParity);
arduino->setStopBits(QSerialPort::OneStop);
arduino->setFlowControl(QSerialPort::NoFlowControl);
}you have to open the serial port after setting the parameters.
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@mimamrafi said in QT reading Serialport of Arduino:
The Serial Port didn't open automatically
What do you mean? Do you mean arduino->open(QIODevice::ReadWrite); returns false (you should check the return value!)?
wrote on 30 Nov 2021, 08:06 last edited by@jsulm yes, it return false. but after I open the serial monitor in Arduino IDE, then I close the serial monitor in arduino ide, then I debug the qt. now it return true. How can I debug the QT without open the serial monitor in arduino ide in the first time?
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@jsulm yes, it return false. but after I open the serial monitor in Arduino IDE, then I close the serial monitor in arduino ide, then I debug the qt. now it return true. How can I debug the QT without open the serial monitor in arduino ide in the first time?
@mimamrafi Please read what @J-Hilk wrote
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@mimamrafi said in QT reading Serialport of Arduino:
void SerialPortManager::openSerialPort()
{
arduino->setPortName("COM8");
arduino->open(QIODevice::ReadWrite);
arduino->setBaudRate(QSerialPort::Baud9600);
arduino->setDataBits(QSerialPort::Data8);
arduino->setParity(QSerialPort::NoParity);
arduino->setStopBits(QSerialPort::OneStop);
arduino->setFlowControl(QSerialPort::NoFlowControl);
}you have to open the serial port after setting the parameters.
wrote on 30 Nov 2021, 08:28 last edited by@J-Hilk it is the command to open the serial port right?
arduino->open(QIODevice::ReadWrite); -
@J-Hilk it is the command to open the serial port right?
arduino->open(QIODevice::ReadWrite);@mimamrafi said in QT reading Serialport of Arduino:
it is the command to open the serial port right?
Yes, it should be AFTER you set the parameters (like setFlowControl).
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@mimamrafi said in QT reading Serialport of Arduino:
it is the command to open the serial port right?
Yes, it should be AFTER you set the parameters (like setFlowControl).
wrote on 30 Nov 2021, 08:43 last edited by mimamrafi@jsulm yes, I have been open it and the output is true, but my issue is the arduino send nothing to serial when I debug the QT first. If I open the serial monitor and close it again then debug the QT, it works properly
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@jsulm yes, I have been open it and the output is true, but my issue is the arduino send nothing to serial when I debug the QT first. If I open the serial monitor and close it again then debug the QT, it works properly
@mimamrafi I don't know how your Arduino side is working, so can't comment
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@jsulm yes, I have been open it and the output is true, but my issue is the arduino send nothing to serial when I debug the QT first. If I open the serial monitor and close it again then debug the QT, it works properly
@mimamrafi said in QT reading Serialport of Arduino:
yes, I have been open it and the output is true
yes, thats obvious, but did you open it after setting the settings ? e.g:
void SerialPortManager::openSerialPort() { arduino->setPortName("COM8"); arduino->setBaudRate(QSerialPort::Baud9600); arduino->setDataBits(QSerialPort::Data8); arduino->setParity(QSerialPort::NoParity); arduino->setStopBits(QSerialPort::OneStop); arduino->setFlowControl(QSerialPort::NoFlowControl); arduino->open(QIODevice::ReadWrite); }assuming of course, those are the same settings as the other program uses.
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@mimamrafi I don't know how your Arduino side is working, so can't comment
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@mimamrafi said in QT reading Serialport of Arduino:
yes, I have been open it and the output is true
yes, thats obvious, but did you open it after setting the settings ? e.g:
void SerialPortManager::openSerialPort() { arduino->setPortName("COM8"); arduino->setBaudRate(QSerialPort::Baud9600); arduino->setDataBits(QSerialPort::Data8); arduino->setParity(QSerialPort::NoParity); arduino->setStopBits(QSerialPort::OneStop); arduino->setFlowControl(QSerialPort::NoFlowControl); arduino->open(QIODevice::ReadWrite); }assuming of course, those are the same settings as the other program uses.
wrote on 30 Nov 2021, 09:13 last edited by@J-Hilk Hey, I've got a clue. I'm using Arduino leonardo, I don't know why it didn't send the serial to QT without open the serial monitor. When I try Arduino UNO, it works properly without open the serial monitor first
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@J-Hilk Hey, I've got a clue. I'm using Arduino leonardo, I don't know why it didn't send the serial to QT without open the serial monitor. When I try Arduino UNO, it works properly without open the serial monitor first
@mimamrafi try adding a sleep/delay at the end of your Arduino loop, see if that improves things.
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@mimamrafi said in QT reading Serialport of Arduino:
it is the command to open the serial port right?
Yes, it should be AFTER you set the parameters (like setFlowControl).
@jsulm said in QT reading Serialport of Arduino:
Yes, it should be AFTER you set the parameters (like setFlowControl).
No. It is irrelevant.
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@jsulm said in QT reading Serialport of Arduino:
Yes, it should be AFTER you set the parameters (like setFlowControl).
No. It is irrelevant.
@kuzulis I was about to vehemently deny this, but then I noticed the setters have boolean return type.
I was only going on the notes from https://doc.qt.io/qt-5/qserialport.html#open
that says it sets the settings during open().did this change in one of the newer versions?apparently not. At least not as far back as 5.12 -
@mimamrafi try adding a sleep/delay at the end of your Arduino loop, see if that improves things.
wrote on 30 Nov 2021, 10:06 last edited by@J-Hilk No, it still print nothing. Maybe, I will switch to arduino uno. It's hardware issue, not the QT. Thanks for help
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wrote on 2 Dec 2021, 03:33 last edited by
Hai everyone. I found some clues about this topic. The serial communication have to enable the DTR (Data Terminal Ready). So this is my current code that I used
void SerialPortManager::openSerialPort() { arduino->setPortName("COM8"); arduino->open(QIODevice::ReadWrite); arduino->setBaudRate(QSerialPort::Baud9600); arduino->setDataBits(QSerialPort::Data8); arduino->setParity(QSerialPort::NoParity); arduino->setStopBits(QSerialPort::OneStop); arduino->setFlowControl(QSerialPort::NoFlowControl); arduino->setDataTerminalReady(true); }Actually, I don't know why its working, but some of tutorial it's not a problem without writing setDataTerminalReady
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J J.Hilk referenced this topic on 3 Jul 2023, 14:35
12/17