問題描述

我想制作一個計算脈沖的程序，然后它會通過一些方程式并將其顯示在 gui 中.這是我的 main.py

i want to make a program that count pulses then it go through some equation and display it in the gui . This my main.py

import sys
import time
import RPi.GPIO as GPIO
import PyQt5
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from mainwindow import Ui_MainWindow
GPIO.setmode(GPIO.BCM)
GPIO.setup(18, GPIO.IN, pull_up_down = GPIO.PUD_UP)
 
class MainWindow(QMainWindow):
 # access variables inside of the UI's file
 def __init__(self):
     super().__init__()
     self.mainwindow = Ui_MainWindow()
     self.mainwindow.setupUi(self)
     self.i=100
     self.flow = 0
     self.flowliter = 0
     self.totalflow=0

     
     self.mainwindow.lcdNumber.display(self.i)
     self.mainwindow.lcdNumber_2.display(self.i)  
     self.show()
     
 
     self.mainwindow.startbttn.clicked.connect(lambda: self.pressedstartButton())
     self.mainwindow.stopbttn.clicked.connect(lambda: self.pressedstopButton())
     
 
 def pressedstartButton(self):
     print ("Pressed On!")
     self.data()
 
 def pressedstopButton(self):
     print ("Pressed Off!")
     
 def data(self) :
     global count
     count = 0

     def countPulse(channel):
      global count
      if start_counter == 1:
          count = count+1

     GPIO.add_event_detect(FLOW_SENSOR, GPIO.FALLING, callback=countPulse)

     while True:
        try:
         start_counter = 1
         time.sleep(1)
         start_counter = 4

         self.flow = (10 * 60)
         self.flowliter= (self.flow/60)
         self.totalflow += self.flowliter
         print("%d"% (count))
         print ("The flow is: %.3f Liter/min" % (self.flow))
         print ("The flowliter is: %.3f Liter" % (self.flowliter))
         print ("The volume is: %.3f Liter" % (self.totalflow))
         self.mainwindow.lcdNumber.display(self.flow)
         self.mainwindow.lcdNumber_2.display(self.flowliter)
         count = 0
         time.sleep(1)
        except KeyboardInterrupt:
         print ('
caught keyboard interrupt!, bye')
         GPIO.cleanup()
         sys.exit()


def main():
     app = QApplication(sys.argv)
     form = MainWindow()
     form.show()
     sys.exit(app.exec_())
 
if __name__ == "__main__":
    main()

lcdnumber 在 gui 中沒有更新，但 shell 中的 self.flow 更新，我想顯示值在 gui 中，但我不知道哪一個適合 qtablewidget 或 qtextbroswer此代碼應計算來自 gpio 18 的脈沖并在 gui 中顯示流程.

the lcdnumber doesnt update in the gui but the self.flow update in the shell and i want display the value in the gui but i dont know which one suitable qtablewidget or qtextbroswer this code should count the pulse from the gpio 18 and show the flow in the gui.

推薦答案

你不應該使用耗時的函數，因為它們會阻塞事件循環，結果是凍結 GUI.在這種情況下，您不應該使用無限循環或 time.sleep，但 QTimer 就足夠了.

You should not use time-consuming functions as they block the eventloop and the consequence is to freeze the GUI. In this case, you should not use an infinite loop or time.sleep but a QTimer is enough.

import sys
import RPi.GPIO as GPIO

from PyQt5.QtWidgets import *
from PyQt5.QtCore import *

from mainwindow import Ui_MainWindow


FLOW_SENSOR = 18


class MainWindow(QMainWindow):
    pinSignal = pyqtSignal()

    def __init__(self):
        super().__init__()
        self.mainwindow = Ui_MainWindow()
        self.mainwindow.setupUi(self)
        self.i = 100
        self.flow = 0
        self.flowliter = 0
        self.totalflow = 0

        self.mainwindow.lcdNumber.display(self.i)
        self.mainwindow.lcdNumber_2.display(self.i)
        self.show()

        self.mainwindow.startbttn.clicked.connect(self.pressedstartButton)
        self.mainwindow.stopbttn.clicked.connect(self.pressedstopButton)

        self.start_counter = False
        self.count = 0

        self.timer = QTimer(self, interval=1000, timeout=self.execute_every_second)
        self.pinSignal.connect(self.handle_pin_signal)

    def pressedstartButton(self):
        print("Pressed On!")
        GPIO.add_event_detect(FLOW_SENSOR, GPIO.FALLING, callback = lambda *args: self.pinSignal.emit())
        self.execute_every_second()
        self.timer.start()

    def pressedstopButton(self):
        print("Pressed Off!")
        self.timer.stop()
        GPIO.remove_event_detect(FLOW_SENSOR)

    def handle_pin_signal(self):
        if self.start_counter:
            self.count += 1

    def execute_every_second(self):
        if not self.start_counter:
            self.flow = 10 * 60
            self.flowliter = self.flow / 60
            self.totalflow += self.flowliter
            print("%d" % (self.count))
            print("The flow is: %.3f Liter/min" % (self.flow))
            print("The flowliter is: %.3f Liter" % (self.flowliter))
            print("The volume is: %.3f Liter" % (self.totalflow))
            self.mainwindow.lcdNumber.display(self.flow)
            self.mainwindow.lcdNumber_2.display(self.flowliter)
            self.count = 0
        self.start_counter = not self.start_counter


def main():
    GPIO.setmode(GPIO.BCM)
    GPIO.setup(FLOW_SENSOR, GPIO.IN, pull_up_down=GPIO.PUD_UP)

    app = QApplication(sys.argv)
    form = MainWindow()
    form.show()
    ret = app.exec_()

    GPIO.cleanup()

    sys.exit(ret)


if __name__ == "__main__":
    main()

這篇關于PyQt5 QLCNumber 沒有更新的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！