（项目实战）基于QT嵌入式ARM数据采集卡上位机（三）—— qwt和fft使用

QWT和FFT的编译这里不做赘述，后面可能会写fft的编译，qwt的编译只需要，qmake和make install，即可编译成功。这篇文章代码，连同上一篇文章的代码即可显示实时曲线。
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• （项目实战）基于QT嵌入式ARM数据采集卡上位机（三）——qwt和fft的基础配置使用
• • • • • 1. qwt设置代码
        • 2. FFT基础使用
      • 整合项目

include(qwt/qwt.pri)
include(fftw2/fftw2.pri)

注意：这里需要添加你自己环境下第三方库的路径。

在使用qwt时，需要在.pro文件中添加

CONFIG += qwt

添加qwt.pri文件

# QWT 安装路径
QWT_INSTALL_PATH = $$PWD

# QWT 插件相关库所在路径（例如：xx.lib）
QWT_LIB_PATH = $$QWT_INSTALL_PATH/lib

# QWT 插件相关头文件所在路径（例如：xx.h）
QWT_INCLUDE_PATH = $$QWT_INSTALL_PATH/include

INCLUDEPATH += $$QWT_INCLUDE_PATH

LIBS += -L$$QWT_LIB_PATH -lqwt
LIBS += -L$$QWT_LIB_PATH -lQt5Concurrent

baseplot.cpp文件对应qwt的使用，代码如下

#include "baseplot.h"
#include "qwt_picker_machine.h"
#include "qwt_scale_widget.h"
#include "qwt_plot_layout.h"
#include "qwt_text.h"
#include "qwt_scale_engine.h"
#include 
#include 
#include 
#include 
#include 
#include 
//#include 
BasePlot::BasePlot(QString str,QWidget *parent) : QWidget(parent)
{
    baseplot = new QwtPlot();
    baseplot->setTitle(str);

//    baseplotsettitle("QString str");
    basePlotCurve = new QwtPlotCurve("I");

    BasePlotInitGui(baseplot,basePlotCurve);
    basePlotCurve->setLegendAttribute(basePlotCurve->LegendShowLine );//show the line style
    showlegend();
}

BasePlot::BasePlot(QWidget *parent): QWidget(parent)
{
    baseplot = new QwtPlot();
    basePlotCurve = new QwtPlotCurve("I");
    BasePlotInitGui(baseplot,basePlotCurve);
}

void BasePlot::plotwave(QVector x, QVector y)
{
//    qDebug() << x <setSamples(x,y);
    baseplot->replot();
}

void BasePlot::plotcurve()
{
    baseplot->replot();
}

void BasePlot::BasePlotInitGui(QwtPlot *basePlot,QwtPlotCurve *baseplotcurve)
{

    QHBoxLayout *hlayout = new QHBoxLayout(this);
    hlayout->addWidget(basePlot);

    baseplotcurve->attach(basePlot);
    baseplotcurve->setPen(QPen(Qt::blue));
    baseplotcurve->setPen(QColor(80,128,128),1.0,Qt::DashLine);


    this->setStyleSheet(" border-radius:8px;");
    this->setStyleSheet("font-family: Palatino Linotype;");
    this->setAttribute(Qt::WA_TranslucentBackground,true); //设置窗体透明
    QSizePolicy sizepolicy;
    sizepolicy.setVerticalPolicy(QSizePolicy::Ignored);
    sizepolicy.setHorizontalPolicy(QSizePolicy::Ignored);//
    basePlot->setSizePolicy(sizepolicy);
}

void BasePlot::baseplotsettitle(QString str)
{
    baseplot->setTitle(str);
}
void BasePlot::setXfixd()
{

}
void BasePlot::AttachPlotCurve(QwtPlotCurve *baseplotcurve,const QPen &pen)
{
    baseplotcurve->attach(baseplot);
    baseplotcurve->setPen(pen);
    baseplotcurve->setLegendAttribute(basePlotCurve->LegendShowLine );//show the line style
}

void BasePlot::showlegend()
{
    QwtLegend *legend = new QwtLegend;
    baseplot->insertLegend(legend, QwtPlot::RightLegend );
}

baseplot.h文件

#ifndef BASEPLOT_H
#define BASEPLOT_H

#include 
#include "qwt_plot.h"
#include "qwt_plot_curve.h"
#include "qwt_plot_grid.h"
#include "qwt_plot_picker.h"
#include "qwt_plot_marker.h"
#include "qwt_plot_zoomer.h"
#include "qwt_plot_panner.h"
#include 
#include 
#include 
class BasePlot : public QWidget
{
    Q_OBJECT
public:
    explicit BasePlot(QString str,QWidget *parent = nullptr);
    explicit BasePlot(QWidget *parent = nullptr);
    void plotwave(QVector x,QVector y);
    void plotcurve();
    void baseplotsettitle(QString str);
    void setXfixd();
    void AttachPlotCurve(QwtPlotCurve *baseplotcurve,const QPen &pen);
    void showlegend();

//   void setStyle();
signals:
private:
    QwtPlot *baseplot;
    QwtPlotCurve *basePlotCurve;
    QTimer replottimer;
    QTimer dataproduce;
    QVector m_xDataVector;                  // x坐标数据
    QVector m_yDataVector;                  // y坐标数据
       unsigned int timecnt = 0;
 void BasePlotInitGui(QwtPlot *basePlot,QwtPlotCurve *baseplotcurve);
};

#endif // BASEPLOT_H

在使用之前，应先添加 fftw2.pri，以保证qt能够找到第三方链接库

# FFTW 安装路径
FFTW_INSTALL_PATH = $$PWD

# FFTW 插件相关库所在路径（例如：xx.lib）
FFTW_LIB_PATH = $$FFTW_INSTALL_PATH/lib

# FFTW 插件相关头文件所在路径（例如：xx.h）
FFTW_INCLUDE_PATH = $$FFTW_INSTALL_PATH/include

INCLUDEPATH += $$FFTW_INCLUDE_PATH

LIBS += -L$$FFTW_LIB_PATH -lfftw3

sllfft.cpp

#include "sllfft.h"
#include 
sllFFT::sllFFT(qint16 len)
{
        nLen = len;
    fftInit(nLen);
}
void sllFFT::pushdata(QVector valueVector)
{
    static QVector fft_In;
    for (int i=0; i= nLen){
            fftunit(fft_In,nLen);
            emit processCompleted(this->xAxis, this->outvalue);
//            qDebug() << outvalue.size();
            fft_In.resize(0);
          // qDebug()<<""<<"t_vector"< Value,qint16 len)
{
    QVector psd_amp(len);
      for (quint16 i = 0;i < len;i ++)
      {
          psd_amp[i] = 0.5*(1-qCos(2*M_PI*i/(len-1)))*qSqrt(1.633);
          Value[i]=Value[i]*psd_amp[i];
      }
      plan_fft = fftw_plan_dft_r2c_1d(len, &Value[0], out_fft, FFTW_ESTIMATE);
      fftw_execute(plan_fft);// 执行变换

      QVector psd_amptemp(len/2);

      for (quint16 i = 0;i < len/2;i ++)
      {
          psd_amptemp[i] = qSqrt(((out_fft[i][0]*out_fft[i][0]+out_fft[i][1]*out_fft[i][1]))
                  /(len*DATA_SAMPLING_FREQ/4));
      }
      fftw_destroy_plan(plan_fft);

      outvalue.resize(psd_amptemp.size());
//    qDebug() << xAxis.size() << outvalue.size();
      for (int i=0;i

#ifndef SLLFFT_H
#define SLLFFT_H

#include 
#include "fftw3.h"
#include 
#include 
class sllFFT : public QObject
{
#define DATA_SAMPLING_FREQ 1000
    Q_OBJECT
public:
    explicit sllFFT(qint16 len);
    void pushdata(QVector valueVector);
signals:
    void processCompleted(QVector t_vectorX, QVector t_vectorY);
private:
    qint16 nLen;
    QVector> outvaluetemp;
    QVector outvalue;
     QVector xAxis;
    fftw_plan plan_fft;
    fftw_complex *out_fft;
    void fftInit(qint16 len);
    void fftunit(QVector Value,qint16 len);
   char AddData(double value);

};
#endif // SLLFFT_H

void functionui::checkboxstyle(QCheckBox *box)
{
    box->setStyleSheet("QCheckBox::indicator {width: 22px; height: 22px;}"
                       "QCheckBox::indicator:checked {image: url(:/icon/redselct.jpg);}");
}

void functionui::signalprintplot(QVector x, QVector y)
{
    signalplot->plotwave(x,y);
}

void functionui::pushfftdata(QVector, QVector y)
{
    fft->pushdata(y);
}

void functionui::fftslot(QVector x, QVector y)
{
    fftplot->plotwave(fftXaxis,y);
}

void functionui::threaddestroy()
{
    qDebug() << "testbutton";
    thread->quit();
    thread->wait();
}

void functionui::texteditshow(QString str)
{
    showtext->insertPlainText(str);
    showtext->insertPlainText("\n");
}

void functionui::texteditshow(quint8 *value)
{
    qDebug() << *value;
    QString str;
    for(quint16 i = 0; i < 5; i ++){
        str.append(*(value+i));
    }
    showtext->insertPlainText(str);
    showtext->insertPlainText("\n");
}
void functionui::texteditshow(QVector value)
{
    Yaxis.append(value);
    if(Yaxis.size() >= 980)
        Yaxis.remove(0,20);
   emit fftsignal(Xaxis, Yaxis);
    if(showchanel1sign) curve->setSamples(Xaxis,Yaxis);
    if(showchanel2sign) chanel2curve->setSamples(Xaxis,Yaxis);
    if(showchanelsign) chanel3curve->setSamples(Xaxis,Yaxis);
    signalplot->plotcurve();
}