我已经尝试了一个多星期以从覆盖物Pi(Qt C (通信到Arduino(Arduino IDE C (,但我一直在失败。
>我在Google上进行了一些搜索,阅读了示例...但我仍然没有成功。好的,所以基本的事情是我需要连续传达从Raspberry Pi到Arduino的串行端口。我试图使代码尽可能简单。
最初,我将Raspberry Pi(QT C (的" J" char发送给Arduino(Arduino IDE C (,并等待该J,以使LED闪烁在Arduino上。但这是行不通的。。。交流&将数据覆盆子PI(QT C (发送到Arduino(Arduino IDE C (。我不知道这是什么问题。请帮助我解决这个问题。
在监视器中,9600 Baudrate
我已经附加了我在两边尝试过的程序。
main.cpp
#include <iostream>
#include <QIODevice>
#include <QtSerialPort/QSerialPort>
#include <QtSerialPort/QSerialPortInfo>
#include <QString>
using namespace std;
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
Dialog w;
w.show();
QSerialPort serialPort;
serialPort.setBaudRate(QSerialPort::Baud9600);
QSerialPortInfo info("ttyUSB0");
qDebug() << "Name : " << info.portName();
qDebug() << "Description : " << info.description();
qDebug() << "Busy:" << info.isBusy();
QSerialPort serial;
serial.setPortName("ttyUSB0");
serial.open(QIODevice::ReadWrite);
serial.setBaudRate(QSerialPort::Baud9600);
serial.setDataBits(QSerialPort::Data8);
serial.setParity(QSerialPort::NoParity);
serial.setStopBits(QSerialPort::OneStop);
serial.setFlowControl(QSerialPort::NoFlowControl);
serial.open(QSerialPort::ReadWrite);
cout<<"Readable :"<<serial.isReadable()<<endl;
cout<<"Writable :"<<serial.isWritable()<<endl<<endl;
if (serial.isOpen() && serial.isWritable())
{
qDebug() << "Is open : " << serial.isOpen() << endl;
qDebug() << "Is writable : " << serial.isWritable() << endl;
qDebug() << "Ready..." << endl;
serial.write("J");
QByteArray ba("Jn");
serial.write(ba);
{
QByteArray ba("J");
serial.write(ba);
serial.flush();
qDebug() << "data has been send" << endl;
serial.close();
}
if (serial.bytesToWrite() > 0)
{
serial.flush();
if(serial.waitForBytesWritten(1000))
{
qDebug() << "data has been send" << endl;
}
}
if(serial.flush())
{
qDebug() << "ok" << endl;
}
qDebug() <<"value sent "<< endl;
serial.close();
}
else
{
qDebug() << "An error occured" << endl;
}
return a.exec();
}
arduino代码:
int led = 13, avlb = 0;
void setup()
{
Serial.begin(9600);
pinMode(led, OUTPUT);
Serial.println("started");
}
void loop()
{
if (Serial.available() > 0)
{
Serial.println("available");
Serial.println(Serial.available());
delay(2000);
digitalWrite(led, HIGH);
delay(5000);
if(Serial.read() == 'J')
{
Serial.println("read");
Serial.println(Serial.read());
delay(2000);
digitalWrite(led, LOW);
delay(1000);
}
}
else
{
Serial.println("not available");
delay(1000);
}
}
显示的输出:
覆盆子QT创建者IDE O/P:
Name : "ttyUSB0"
Description : "FT232R USB UART"
Busy: false
Readable :1
Writable :1
Is open : true
Is writable : true
Ready...
data has been send
bool QSerialPort::flush(): device not open
value sent
Arduino IDE输出显示:
started
not available
not available
not available
not available
not available
not available
not available
not available
not available
我建议您阅读有关QT事件系统的工作原理。所有QT iodevice派生的类都不同步地工作。您需要使用Qapplication来托管其对象系统。之后,您需要更改代码,以免它阻止QSerialport的IO线程。
我通常使用ReadyRead Singal,或者使用WaitforBytesWritten和WaitforreadReady组合。您应该查看QTSerialPort示例。您会发现其中的几个可能的实现,具体取决于您的应用程序需求。
您可以尝试一下,它可以正常工作。
#include <QCoreApplication>
#include <iostream>
#include <QSerialPort>
#include <QDebug>
#include <Windows.h>
#include <QElapsedTimer>
using namespace std;
QSerialPort serial;
QElapsedTimer timer;
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
serial.setPortName("ttyUSB0");
serial.open(QIODevice::ReadWrite);
serial.setBaudRate(QSerialPort::Baud9600);
serial.setDataBits(QSerialPort::Data8);
serial.setParity(QSerialPort::NoParity);
serial.setStopBits(QSerialPort::OneStop);
serial.setFlowControl(QSerialPort::NoFlowControl);
while(!serial.isOpen()) serial.open(QIODevice::ReadWrite);
if (serial.isOpen() && serial.isWritable())
{
qDebug() << "Serial is open";
QByteArray output;
QByteArray input;
while(true)
{
output = "a";
serial.write(output);
serial.flush();
timer.start();
// Sleep(80);
qDebug() << timer.elapsed();
serial.waitForBytesWritten(100);
serial.waitForReadyRead(100);
if(serial.bytesAvailable()>=18)
input = serial.read(18);
qDebug()<<input;
}
}
return a.exec();
}
您问题的答案在以下代码中:
QByteArray ba("J");
serial.write(ba);
serial.flush();
qDebug() << "data has been send" << endl;
serial.close();
制作serial.flush ()
后,您立即关闭端口。有必要等到数据真正发送。例如,使用bool QSerialPort :: waitForBytesWritten (int msecs)
。