树莓派GUI-ADC测量-PySide/PyQT/QML/Python/Qt

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本文介绍在树莓派上使用python和qt开发一个显示ADC数据的GUI程序。开发环境使用PyCharm进行python代码远程开发,然后使用QtCreator编写QML界面。

1、新建项目

1.1、新建工程

打开PyCharm,新建工程adcMeasure,如下:

1.2、添加python主程序

adcMeasure.py 主程序如下:

import os
import sys
from pathlib import Path

from PySide2.QtCore import Qt, QObject, Slot
from PySide2.QtQml import QQmlApplicationEngine
from PySide2.QtWidgets import QApplication

from adc_mcp3424 import MCP3424


class Controler(QObject):
    def __init__(self):
        super().__init__()

        self.MCP3424 = MCP3424(6, address=0x68, rate=18)

    @Slot()
    def exit(self):
        sys.exit()

    @Slot(result=float)
    def get_adc1(self):
        adc1 = self.MCP3424.read_raw(1)
        adc1 = adc1/100.00
        # print("adc1:",adc1)
        return adc1
    
......


if __name__=='__main__':
    a = QApplication(sys.argv)
    a.setOverrideCursor(Qt.BlankCursor)

    engine = QQmlApplicationEngine()

    controler = Controler()
    context = engine.rootContext()
    context.setContextProperty("_Controler", controler)

    engine.load(os.fspath(Path(__file__).resolve().parent / "ui/adcMeasure.qml"))

    if not engine.rootObjects():
        sys.exit(-1)

    sys.exit(a.exec_())
  • 程序中新建一个Controler类,用于获取ADC数值,并将ADC值传递到GUI界面进行显示。
1.3、添加界面文件
  • 在项目中添加ui文件夹,并新建main.qml文件;
import QtQuick 2.11
import QtQuick.Window 2.4
import QtQuick.Controls 2.4
import QtQuick.Controls.Styles 1.4
import QtQuick.Extras 1.4
import QtGraphicalEffects 1.0
import QtCharts 2.2

ApplicationWindow{
    id:root
    width: 800
    height: 480
    visible: true
//    visibility: Window.FullScreen

    background: Rectangle{
        anchors.fill: parent
        color: "#101010"
    }

    Button{
        id:btnexit
        background: Rectangle{
            color: "#a01010"
            anchors.fill: parent
            radius:12
        }
        width: 48
        height: 48
        anchors{
            top: parent.top
            right: parent.right
            topMargin: 8
            rightMargin: 8
        }
        Text {
            text: qsTr("X")
            anchors.centerIn: parent
            font{
                pointSize: 32
            }
            color: "white"
        }
        onClicked: {
            _Controler.exit();
        }
    }

    Text {
        id: title
        text: qsTr("ADC Measure")
        anchors{
            top:  parent.top
            horizontalCenter: parent.horizontalCenter
            topMargin: 20
        }
        font{
            pointSize: 24
        }
        color: "#a0a0a0"
    }

    ChartView{
        id:cv
        width:600
        height:400

        anchors{
            top:title.bottom
            topMargin:10
            left:parent.left
            leftMargin:40
        }
        antialiasing: true
        theme: ChartView.ChartThemeDark

        property int  timcnt: 0
        property double  valueCH1: 0
        property double  valueCH2: 0
        property double  valueCH3: 0
        property double  valueCH4: 0

        ValueAxis{
            id:xAxis
            min: cv.timcnt < 10 ? 0 : cv.timcnt - 10
            max: cv.timcnt < 10 ? 10 : cv.timcnt + 1
            tickCount: 11
            labelFormat: "%d"
        }

        ValueAxis{
            id:yAxis
            min: 0
            max: 500
            tickCount: 1
            labelFormat: "%d"
        }

        LineSeries {
            name: "CH1"
            id:lines1
            axisX: xAxis
            axisY: yAxis
            width: 3
            color: "#1267D4"
        }

        LineSeries {
            name: "CH2"
            id:lines2
            axisX: xAxis
            axisY: yAxis
            width: 3
            color: "#8D7A1F"
        }

        LineSeries {
            name: "CH3"
            id:lines3
            axisX: xAxis
            axisY: yAxis
            width: 3
            color: "#8A1E1D"
        }

        LineSeries {
            name: "CH4"
            id:lines4
            axisX: xAxis
            axisY: yAxis
            width: 3
            color: "#C21FE4"
        }

        Timer{
            id:tm
            interval: 1000
            repeat: true
            running: true
            onTriggered: {
                cv.timcnt = cv.timcnt + 1
                cv.valueCH1 = _Controler.get_adc1()
                cv.valueCH2 = _Controler.get_adc2()
                cv.valueCH3 = _Controler.get_adc3()
                cv.valueCH4 = _Controler.get_adc4()

                lines1.append(cv.timcnt,cv.valueCH1)
                lines2.append(cv.timcnt,cv.valueCH2)
                lines3.append(cv.timcnt,cv.valueCH3)
                lines4.append(cv.timcnt,cv.valueCH4)

                console.log("--------------------")
                console.log("qml adc value1:",cv.valueCH1)
                console.log("qml adc value2:",cv.valueCH2)
                console.log("qml adc value3:",cv.valueCH3)
                console.log("qml adc value4:",cv.valueCH4)

            }
        }
    }
}

  • 使用 ChartView 模块进行ADC数值显示,建立一个 Timer 定时器,每秒获取一次ADC值,然后添加到曲线中进行显示。

2、执行程序

2.1、上传程序到树莓派

在工程上右键将这个项目文件上传到树莓派中:

2.2、ADC硬件

树莓派连接一个I2C接口的ADC模块,这里使用的是MCP3424,它拥有四通道最大18位的精度。将四个可调变阻器连接到ADC四个通道上,这样通过调节电阻来测试变化的模拟值。

2.3、执行程序

上传后,在树莓派对应文件夹中,执行如下命令执行程序:

python3 adcMeasure.py

执行后可以看到显示如下:

当调节电阻时候,可以看到其变化曲线:

完整代码:

github

  • 视频效果:

www.bilibili.com/video/BV1jM…