问题描述
我想制作一个对脉冲进行计数的程序，然后通过一个方程式并将其显示在gui中。 这是我的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 ('\ncaught 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不会在gui中更新，但是self.flow会在shell中更新，我想显示该值 在GUI中，但我不知道哪个合适的qtablewidget或qtextbroswer 该代码应计算来自gpio 18的脉冲并在gui中显示流量。
解决方法
您不应使用耗时的函数，因为它们会阻塞事件循环，从而冻结GUI。在这种情况下，您不应使用无限循环或time.sleep，而使用QTimer即可。
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()