使用 python3.5 将 Arduino 的实时数据链接到 pyqt5 的 LCDNumber

我对制作 GUI 还很陌生。我为一个项目设计了一个项目，我希望在数据从 Arduino 传入时更新 LCD。我正在使用 pyqt5 来转换我的 Qtdesigner GUI。问题是我不知道如何将传入数据链接到 GUI。

目前，我有一个程序可以收集我想要的所有数据，并打开由 Qtdesigner 创建的显示。在图片中，我附加了所选 LCD，其名称为：lcdNumber_4。

"""
SCSU DYNO GUI PROGRAM

created 10/20/2017

"""


import sys
import time
import serial
import serial.tools.list_ports
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore import QThread,QTimer
from PyQt5.QtWidgets import QMessageBox,QWidget
from DynoTest1 import Ui_DynoTest1
import csv
import numpy as np
import warnings
import serial
import serial.tools.list_ports

__author__ = 'Matt Munn'

class GetData(QThread):
    def __init__(self):        

        QThread.__init__(self)

        arduino_ports = [ # automatically searches for an Arduino and selects the port it's on
            p.device
            for p in serial.tools.list_ports.comports()
            if 'Arduino' in p.description
        ]
        if not arduino_ports:
            raise IOError("No Arduino found - is it plugged in? If so, restart computer.")
        if len(arduino_ports) > 1:
            warnings.warn('Multiple Arduinos found - using the first')
        self.ArduinoData = serial.Serial(arduino_ports[0], 9600, timeout = 1)
        self.ArduinoData.close()
        self.ArduinoData.open()


        self.Arduino.flush()
        self.Arduino.reset_input_buffer()

        start_time=time.time()
        Distance = 0.5 # This is how long the lever arm is in feet

    def __del__(self): # part of the standard format of a QThread

        self.wait()
    def run(self): # also a required QThread function, the working part    

        while True:
            while (Arduino.inWaiting()==0):
                pass
            try:
                data = Arduino.readline()
                dataarray = data.decode().rstrip().split(',')
                Arduino.reset_input_buffer()
                Force = round(float(dataarray[0]),3)
                RPM = round(float (dataarray[1]),3)
                Torque = round(Force * Distance,3)
                HorsePower = round(Torque * RPM / 5252,3)
                Run_Time = round(time.time()-start_time,3)
                print (Force , 'Grams',"," , RPM ,'RPMs',"," ,Torque,"ft-lbs",",", HorsePower, "hp", Run_Time, "Time Elasped")
            except (KeyboardInterrupt, SystemExit,IndexError,ValueError):
                pass


class GUI(Ui_DynoTest1): # create GUI and functionality



    def __init__(self):
        self.MainWindow = QtWidgets.QWidget() # pull code from DynoTest1.py and initialize
        self.setupUi(self.MainWindow)




def main(): # follow PYQT5 proper format for a GUI

    app=QtWidgets.QApplication(sys.argv)    
    Dyno = GUI()
    Dyno.MainWindow.show()
    sys.exit(app.exec_())
# In[8]:
if __name__ == '__main__':

    main()

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'dynotest1.ui'
#
# Created by: PyQt5 UI code generator 5.9
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_DynoTest1(object):
    def setupUi(self, DynoTest1):
        DynoTest1.setObjectName("DynoTest1")
        DynoTest1.resize(1001, 695)
        self.verticalLayout_4 = QtWidgets.QVBoxLayout(DynoTest1)
        self.verticalLayout_4.setObjectName("verticalLayout_4")
        self.horizontalLayout_2 = QtWidgets.QHBoxLayout()
        self.horizontalLayout_2.setObjectName("horizontalLayout_2")
        self.horizontalLayout = QtWidgets.QHBoxLayout()
        self.horizontalLayout.setObjectName("horizontalLayout")
        self.verticalLayout_3 = QtWidgets.QVBoxLayout()
        self.verticalLayout_3.setObjectName("verticalLayout_3")
        self.gridLayout = QtWidgets.QGridLayout()
        self.gridLayout.setObjectName("gridLayout")
        self.pushButton_2 = QtWidgets.QPushButton(DynoTest1)
        self.pushButton_2.setObjectName("pushButton_2")
        self.gridLayout.addWidget(self.pushButton_2, 1, 0, 1, 1)
        self.pushButton_4 = QtWidgets.QPushButton(DynoTest1)
        self.pushButton_4.setObjectName("pushButton_4")
        self.gridLayout.addWidget(self.pushButton_4, 1, 1, 1, 1)
        self.pushButton_3 = QtWidgets.QPushButton(DynoTest1)
        self.pushButton_3.setObjectName("pushButton_3")
        self.gridLayout.addWidget(self.pushButton_3, 0, 1, 1, 1)
        self.pushButton = QtWidgets.QPushButton(DynoTest1)
        self.pushButton.setObjectName("pushButton")
        self.gridLayout.addWidget(self.pushButton, 0, 0, 1, 1)
        self.verticalLayout_3.addLayout(self.gridLayout)
        self.label_3 = QtWidgets.QLabel(DynoTest1)
        self.label_3.setObjectName("label_3")
        self.verticalLayout_3.addWidget(self.label_3)
        self.label_2 = QtWidgets.QLabel(DynoTest1)
        self.label_2.setObjectName("label_2")
        self.verticalLayout_3.addWidget(self.label_2)
        self.label = QtWidgets.QLabel(DynoTest1)
        self.label.setObjectName("label")
        self.verticalLayout_3.addWidget(self.label)
        self.horizontalLayout.addLayout(self.verticalLayout_3)
        self.verticalLayout = QtWidgets.QVBoxLayout()
        self.verticalLayout.setObjectName("verticalLayout")
        self.label_5 = QtWidgets.QLabel(DynoTest1)
        self.label_5.setObjectName("label_5")
        self.verticalLayout.addWidget(self.label_5)
        self.lcdNumber_4 = QtWidgets.QLCDNumber(DynoTest1)
        self.lcdNumber_4.setObjectName("lcdNumber_4")
        self.verticalLayout.addWidget(self.lcdNumber_4)
        self.lcdNumber_5 = QtWidgets.QLCDNumber(DynoTest1)
        self.lcdNumber_5.setObjectName("lcdNumber_5")
        self.verticalLayout.addWidget(self.lcdNumber_5)
        self.lcdNumber_6 = QtWidgets.QLCDNumber(DynoTest1)
        self.lcdNumber_6.setObjectName("lcdNumber_6")
        self.verticalLayout.addWidget(self.lcdNumber_6)
        self.horizontalLayout.addLayout(self.verticalLayout)
        self.verticalLayout_2 = QtWidgets.QVBoxLayout()
        self.verticalLayout_2.setObjectName("verticalLayout_2")
        self.label_6 = QtWidgets.QLabel(DynoTest1)
        self.label_6.setObjectName("label_6")
        self.verticalLayout_2.addWidget(self.label_6)
        self.lcdNumber = QtWidgets.QLCDNumber(DynoTest1)
        self.lcdNumber.setObjectName("lcdNumber")
        self.verticalLayout_2.addWidget(self.lcdNumber)
        self.lcdNumber_2 = QtWidgets.QLCDNumber(DynoTest1)
        self.lcdNumber_2.setObjectName("lcdNumber_2")
        self.verticalLayout_2.addWidget(self.lcdNumber_2)
        self.lcdNumber_3 = QtWidgets.QLCDNumber(DynoTest1)
        self.lcdNumber_3.setObjectName("lcdNumber_3")
        self.verticalLayout_2.addWidget(self.lcdNumber_3)
        self.horizontalLayout.addLayout(self.verticalLayout_2)
        self.horizontalLayout_2.addLayout(self.horizontalLayout)
        self.verticalLayout_5 = QtWidgets.QVBoxLayout()
        self.verticalLayout_5.setObjectName("verticalLayout_5")
        self.label_7 = QtWidgets.QLabel(DynoTest1)
        self.label_7.setObjectName("label_7")
        self.verticalLayout_5.addWidget(self.label_7)
        self.lcdNumber_7 = QtWidgets.QLCDNumber(DynoTest1)
        self.lcdNumber_7.setObjectName("lcdNumber_7")
        self.verticalLayout_5.addWidget(self.lcdNumber_7)
        self.horizontalLayout_2.addLayout(self.verticalLayout_5)
        self.verticalLayout_4.addLayout(self.horizontalLayout_2)
        self.graphicsView = QtWidgets.QGraphicsView(DynoTest1)
        self.graphicsView.setStyleSheet("border-image: url(:/newPrefix/husky_head5.png);")
        self.graphicsView.setObjectName("graphicsView")
        self.verticalLayout_4.addWidget(self.graphicsView)

        self.retranslateUi(DynoTest1)
        QtCore.QMetaObject.connectSlotsByName(DynoTest1)

    def retranslateUi(self, DynoTest1):
        _translate = QtCore.QCoreApplication.translate
        DynoTest1.setWindowTitle(_translate("DynoTest1", "DynoTest1"))
        self.pushButton_2.setText(_translate("DynoTest1", "Pause"))
        self.pushButton_4.setText(_translate("DynoTest1", "Print"))
        self.pushButton_3.setText(_translate("DynoTest1", "Stop"))
        self.pushButton.setText(_translate("DynoTest1", "Start"))
        self.label_3.setText(_translate("DynoTest1", "<html><head/><body><p align=\"center\"><span style=\" font-size:18pt; font-weight:600;\">RPMs</span></p></body></html>"))
        self.label_2.setText(_translate("DynoTest1", "<html><head/><body><p align=\"center\"><span style=\" font-size:18pt; font-weight:600;\">Torque (ft-lbs)</span></p></body></html>"))
        self.label.setText(_translate("DynoTest1", "<html><head/><body><p align=\"center\"><span style=\" font-size:18pt; font-weight:600;\">Horse Power</span></p></body></html>"))
        self.label_5.setText(_translate("DynoTest1", "<html><head/><body><p align=\"center\"><span style=\" font-size:18pt; font-weight:600;\">Now</span></p></body></html>"))
        self.label_6.setText(_translate("DynoTest1", "<html><head/><body><p align=\"center\"><span style=\" font-size:18pt; font-weight:600;\">Max</span></p></body></html>"))
        self.label_7.setText(_translate("DynoTest1", "<html><head/><body><p align=\"center\"><span style=\" font-size:18pt; font-weight:600;\">Run Time</span></p></body></html>"))

import Resource_rc

为了正确操作，我修改了一些变量的名称，因为它们与它们的用途不符。为了在元素之间发送信息PyQt建议使用信号和槽，为此您必须在中创建信号QThread发送需要在 GUI 中显示的信息，为此我们使用pyqtSignal()我们在其中指示要发送的参数类型。

class GetData(QThread):
    dataChanged = pyqtSignal(float, float, float, float)
    Distance = 0.5

    def __init__(self, parent=None):
        QThread.__init__(self, parent)

        arduino_ports = [  # automatically searches for an Arduino and selects the port it's on
            p.device
            for p in serial.tools.list_ports.comports()
            if 'Arduino' in p.description
        ]

        if not arduino_ports:
            raise IOError("No Arduino found - is it plugged in? If so, restart computer.")
        if len(arduino_ports) > 1:
            warnings.warn('Multiple Arduinos found - using the first')
        self.Arduino = serial.Serial(arduino_ports[0], 9600, timeout=1)

    def __del__(self):  # part of the standard format of a QThread
        self.wait()

    def run(self):  # also a required QThread function, the working part
        self.Arduino.close()
        self.Arduino.open()

        self.Arduino.flush()
        self.Arduino.reset_input_buffer()
        start_time = time.time()

        while True:
            while self.Arduino.inWaiting() == 0:
                pass
            try:
                data = self.Arduino.readline()
                dataarray = data.decode().rstrip().split(',')
                self.Arduino.reset_input_buffer()
                Force = round(float(dataarray[0]), 3)
                RPM = round(float(dataarray[1]), 3)
                Torque = round(Force * GetData.Distance, 3)
                HorsePower = round(Torque * RPM / 5252, 3)
                Run_Time = round(time.time() - start_time, 3)
                print(Force, 'Grams', ",", RPM, 'RPMs', ",", Torque, "ft-lbs", ",", HorsePower, "hp", Run_Time,
                      "Time Elasped")
                self.dataChanged.emit(RPM, Torque, HorsePower, Run_Time)
            except (KeyboardInterrupt, SystemExit, IndexError, ValueError):
                pass

Qt Designer提供了一个设计，不提供一个小部件，因为最好创建一个继承自小部件的类并使用该设计，创建一个QThread实例并将dataChanged信号连接到某个插槽，并且在该插槽中我们将值放入 QLCDNumber 中。

class GUI(QWidget, Ui_DynoTest1):
    def __init__(self, parent=None):
        QWidget.__init__(self, parent)
        self.setupUi(self)
        self.thread = GetData(self)
        self.thread.dataChanged.connect(self.onDataChanged)
        self.thread.start()

    def onDataChanged(self, RPM, Torque, HorsePower, Run_Time):
        self.lcdNumber_4.display(RPM)
        self.lcdNumber_5.display(Torque)
        self.lcdNumber_6.display(HorsePower)
        self.lcdNumber_7.display(Run_Time)


if __name__ == '__main__':
    import sys
    app = QApplication(sys.argv)
    Dyno = GUI()
    Dyno.show()
    sys.exit(app.exec_())