如何在 Python 中创建不断更新的标签
How to create a constantly updating label in Python
我有一个 Raspberry pi 并使用 Python 我已经编写了一个 GUI 来使用 PWM 控制风扇并从风扇脉冲输出计算出 RPM。 GUI 的顶部有一个标签，select 不同工作周期的按钮，一个 LED 标志指示器显示哪个按钮被 selected，按钮 'STOP FAN'，'Exit'， 'Display RPM'.
我使用 'Start Fan' 按钮启动风扇。然后我可以 select 不同的占空比。当我单击 'Display RPM' 按钮时，GUI 顶部的标签显示 RPM（小数点后有很多数字），它只是 RPM 的快速快照。我的代码运行正常。
我的问题是这样的。如何让标签不断显示不断变化的 RPM？我想删除 'Display RPM' 按钮，让标签始终显示实时变化的 RPM。
我在谷歌上搜索了几个小时寻求帮助，并尝试了 'after'、'function calls' 等。但我似乎无法理解我需要做什么或它应该放在代码中的什么位置。
非常感谢您的宝贵时间和帮助。
代码可能不是我所知道的最好的，但我正在学习。我很乐意接受有关如何改进它的任何建议。
# Fan PWM Control
import time
from time import sleep
import piface.pfio as pfio
pfio.init()
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BOARD)
GPIO.setup(7,GPIO.OUT)
GPIO.setup(18,GPIO.IN,pull_up_down=GPIO.PUD_UP)
my_pwm = GPIO.PWM(7,1000)
last_time = time.time()
this_time = time.time()
RPM = 0
from Tkinter import *
import Tkinter as tk
a=0
class App:
def __init__(self, master):
self.master=master
frame = Frame(master)
frame.pack()
self.TACHO = Label(frame, text=RPM)
self.TACHO.grid(row=0, column=0)
self.button0 = Button(frame, text='Start Fan', command=self.convert0)
self.button0.grid(row=2, column=0)
self.LED0 = Label(frame, image=logo2)
self.LED0.grid(row=2, column=1)
self.button1 = Button(frame, text='Fan 30% Duty Cycle', command=self.convert1)
self.button1.grid(row=3, column=0)
self.LED1 = Label(frame, image=logo2)
self.LED1.grid(row=3, column=1)
self.button2 = Button(frame, text='Fan 45% Duty Cycle', command=self.convert2)
self.button2.grid(row=4, column=0)
self.LED2 = Label(frame, image=logo2)
self.LED2.grid(row=4, column=1)
self.button3 = Button(frame, text='Fan 60% Duty Cycle', command=self.convert3)
self.button3.grid(row=5, column=0)
self.LED3 = Label(frame, image=logo2)
self.LED3.grid(row=5, column=1)
self.button4 = Button(frame, text='Fan 75% Duty Cycle', command=self.convert4)
self.button4.grid(row=6, column=0)
self.LED4 = Label(frame, image=logo2)
self.LED4.grid(row=6, column=1)
self.button5 = Button(frame, text='Fan 90% Duty Cycle', command=self.convert5)
self.button5.grid(row=7, column=0)
self.LED5 = Label(frame, image=logo2)
self.LED5.grid(row=7, column=1)
self.button6 = Button(frame, text='Fan 100% Duty Cycle', command=self.convert6)
self.button6.grid(row=8, column=0)
self.LED6 = Label(frame, image=logo2)
self.LED6.grid(row=8, column=1)
self.button7 = Button(frame, text='STOP FAN', command=self.convert7)
self.button7.grid(row=9, column=0)
self.button8 = Button(frame, text='Exit', command=self.convert8)
self.button8.grid(row=10, column=0)
self.button9 = Button(frame, text='Display RPM', command=self.Tach)
self.button9.grid(row=11, column=0)
def convert0(self):
print('Fan 15% Duty Cycle')
global a
a = 1
self.button0.config(text='Fan 15% Duty Cycle')
self.LED0.config(image = logo)
my_pwm.start(15)
pfio.digital_write(0,1) #turn on
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert1(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 30% Duty Cycle')
self.button1.config(text='Fan 30% Duty Cycle')
self.LED1.config(image = logo)
my_pwm.ChangeDutyCycle(30)
pfio.digital_write(1,1) #turn on
self.LED0.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert2(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 45% Duty Cycle')
self.button2.config(text='Fan 45% Duty Cycle')
self.LED2.config(image = logo)
my_pwm.ChangeDutyCycle(45)
pfio.digital_write(2,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert3(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 60% Duty Cycle')
self.button3.config(text='Fan 60% Duty Cycle')
self.LED3.config(image = logo)
my_pwm.ChangeDutyCycle(60)
pfio.digital_write(3,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert4(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 75% Duty Cycle')
self.button4.config(text='Fan 75% Duty Cycle')
self.LED4.config(image = logo)
my_pwm.ChangeDutyCycle(75)
pfio.digital_write(4,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert5(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 90% Duty Cycle')
self.button5.config(text='Fan 90% Duty Cycle')
self.LED5.config(image = logo)
my_pwm.ChangeDutyCycle(90)
pfio.digital_write(5,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert6(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 100% Duty Cycle')
self.button6.config(text='Fan 100% Duty Cycle')
self.LED6.config(image = logo)
my_pwm.ChangeDutyCycle(100)
pfio.digital_write(6,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(7,0) #turn off
def convert7(self):
print('STOP FAN')
global a
a = 0
self.button7.config(text='STOP FAN')
my_pwm.stop()
pfio.digital_write(7,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
self.button0.config(text='Start Fan')
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
def convert8(self):
print('EXIT PROGRAM')
my_pwm.stop()
quit()
def EventsPerTime(self):
global RPM, this_time, last_time
if GPIO.input(self) > 0.5:
this_time = time.time()
RPM = (1/(this_time - last_time))*30
last_time = this_time
#print 'RPM is %d' % RPM
GPIO.add_event_detect(18, GPIO.RISING, callback=EventsPerTime, bouncetime=3)
def Tach(self):
global RPM
if RPM > 1:
print 'RPM is %d' % RPM
self.TACHO.config(text=RPM)
root = Tk()
logo2 = PhotoImage(file="/home/pi/Off LED.gif")
logo = PhotoImage(file="/home/pi/Red LED.gif")
root.wm_title('FAN PWM Control program')
app = App(root)
root.mainloop()
您已有一个获取当前 RPM 的函数。最简单的事情就是在那里更新标签：
def EventsPerTime(self):
global RPM, this_time, last_time
if GPIO.input(self) > 0.5:
...
RPM = (1/(this_time - last_time))*30
...
self.TACHO.configure(text=RPM)
问题的另一部分是您错误地指定了回叫。您需要更改此代码：
GPIO.add_event_detect(..., callback=EventsPerTime, ...)
对此：
GPIO.add_event_detect(..., callback=self.EventsPerTime, ...)
您还必须重新定义 EventsPerTIme 以接受附加参数：
def EventsPerTime(self, channel):
...
以下是我 Raspberry Pi 上显示 RPM 的 PWM GUI 控件的代码更改。由于良好的反馈和通过此 post 和网站提供的帮助，我设法获得了程序 运行 并实现了我的目标。该代码可能没有达到应有的水平或效率，因此请随时提供改进建议。
感谢您的帮助和分享知识。
#self.button9 = Button(frame, text='Display RPM', command=self.Tach) Stopped using this button
#self.button9.grid(row=11, column=0) Stopped using this button
self.TimerInterval = 500 #This sets the time interval between RPM readings
self.Tach() #This will start the 'Tach' method when the GUI starts
def convert0(self):
我还为 'Tach' 编写了一个方法，该方法使用 'after' 函数，该函数将在设定的时间间隔后调用给定的函数。所以我将它设置为每 500 毫秒调用一次。
def Tach(self):
print 'RPM is %d' % RPM
self.TACHO.config(text='RPM is %d' % RPM)
self.master.after(self.TimerInterval,self.Tach) #Used 'after' to repeat this method at the time interval
我还不确定如何停止 'after' 函数，但我会着手解决这个问题并一路学习。
我有一个 Raspberry pi 并使用 Python 我已经编写了一个 GUI 来使用 PWM 控制风扇并从风扇脉冲输出计算出 RPM。 GUI 的顶部有一个标签，select 不同工作周期的按钮，一个 LED 标志指示器显示哪个按钮被 selected，按钮 'STOP FAN'，'Exit'， 'Display RPM'.
我使用 'Start Fan' 按钮启动风扇。然后我可以 select 不同的占空比。当我单击 'Display RPM' 按钮时，GUI 顶部的标签显示 RPM（小数点后有很多数字），它只是 RPM 的快速快照。我的代码运行正常。
我的问题是这样的。如何让标签不断显示不断变化的 RPM？我想删除 'Display RPM' 按钮，让标签始终显示实时变化的 RPM。 我在谷歌上搜索了几个小时寻求帮助，并尝试了 'after'、'function calls' 等。但我似乎无法理解我需要做什么或它应该放在代码中的什么位置。
非常感谢您的宝贵时间和帮助。 代码可能不是我所知道的最好的，但我正在学习。我很乐意接受有关如何改进它的任何建议。
# Fan PWM Control
import time
from time import sleep
import piface.pfio as pfio
pfio.init()
import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BOARD)
GPIO.setup(7,GPIO.OUT)
GPIO.setup(18,GPIO.IN,pull_up_down=GPIO.PUD_UP)
my_pwm = GPIO.PWM(7,1000)
last_time = time.time()
this_time = time.time()
RPM = 0
from Tkinter import *
import Tkinter as tk
a=0
class App:
def __init__(self, master):
self.master=master
frame = Frame(master)
frame.pack()
self.TACHO = Label(frame, text=RPM)
self.TACHO.grid(row=0, column=0)
self.button0 = Button(frame, text='Start Fan', command=self.convert0)
self.button0.grid(row=2, column=0)
self.LED0 = Label(frame, image=logo2)
self.LED0.grid(row=2, column=1)
self.button1 = Button(frame, text='Fan 30% Duty Cycle', command=self.convert1)
self.button1.grid(row=3, column=0)
self.LED1 = Label(frame, image=logo2)
self.LED1.grid(row=3, column=1)
self.button2 = Button(frame, text='Fan 45% Duty Cycle', command=self.convert2)
self.button2.grid(row=4, column=0)
self.LED2 = Label(frame, image=logo2)
self.LED2.grid(row=4, column=1)
self.button3 = Button(frame, text='Fan 60% Duty Cycle', command=self.convert3)
self.button3.grid(row=5, column=0)
self.LED3 = Label(frame, image=logo2)
self.LED3.grid(row=5, column=1)
self.button4 = Button(frame, text='Fan 75% Duty Cycle', command=self.convert4)
self.button4.grid(row=6, column=0)
self.LED4 = Label(frame, image=logo2)
self.LED4.grid(row=6, column=1)
self.button5 = Button(frame, text='Fan 90% Duty Cycle', command=self.convert5)
self.button5.grid(row=7, column=0)
self.LED5 = Label(frame, image=logo2)
self.LED5.grid(row=7, column=1)
self.button6 = Button(frame, text='Fan 100% Duty Cycle', command=self.convert6)
self.button6.grid(row=8, column=0)
self.LED6 = Label(frame, image=logo2)
self.LED6.grid(row=8, column=1)
self.button7 = Button(frame, text='STOP FAN', command=self.convert7)
self.button7.grid(row=9, column=0)
self.button8 = Button(frame, text='Exit', command=self.convert8)
self.button8.grid(row=10, column=0)
self.button9 = Button(frame, text='Display RPM', command=self.Tach)
self.button9.grid(row=11, column=0)
def convert0(self):
print('Fan 15% Duty Cycle')
global a
a = 1
self.button0.config(text='Fan 15% Duty Cycle')
self.LED0.config(image = logo)
my_pwm.start(15)
pfio.digital_write(0,1) #turn on
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert1(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 30% Duty Cycle')
self.button1.config(text='Fan 30% Duty Cycle')
self.LED1.config(image = logo)
my_pwm.ChangeDutyCycle(30)
pfio.digital_write(1,1) #turn on
self.LED0.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert2(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 45% Duty Cycle')
self.button2.config(text='Fan 45% Duty Cycle')
self.LED2.config(image = logo)
my_pwm.ChangeDutyCycle(45)
pfio.digital_write(2,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert3(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 60% Duty Cycle')
self.button3.config(text='Fan 60% Duty Cycle')
self.LED3.config(image = logo)
my_pwm.ChangeDutyCycle(60)
pfio.digital_write(3,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert4(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 75% Duty Cycle')
self.button4.config(text='Fan 75% Duty Cycle')
self.LED4.config(image = logo)
my_pwm.ChangeDutyCycle(75)
pfio.digital_write(4,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert5(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 90% Duty Cycle')
self.button5.config(text='Fan 90% Duty Cycle')
self.LED5.config(image = logo)
my_pwm.ChangeDutyCycle(90)
pfio.digital_write(5,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED6.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(6,0) #turn off
pfio.digital_write(7,0) #turn off
def convert6(self):
if a==0:
print('Please Start the Fan')
else:
print('Fan 100% Duty Cycle')
self.button6.config(text='Fan 100% Duty Cycle')
self.LED6.config(image = logo)
my_pwm.ChangeDutyCycle(100)
pfio.digital_write(6,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(7,0) #turn off
def convert7(self):
print('STOP FAN')
global a
a = 0
self.button7.config(text='STOP FAN')
my_pwm.stop()
pfio.digital_write(7,1) #turn on
self.LED0.config(image = logo2)
self.LED1.config(image = logo2)
self.LED2.config(image = logo2)
self.LED3.config(image = logo2)
self.LED4.config(image = logo2)
self.LED5.config(image = logo2)
self.LED6.config(image = logo2)
self.button0.config(text='Start Fan')
pfio.digital_write(0,0) #turn off
pfio.digital_write(1,0) #turn off
pfio.digital_write(2,0) #turn off
pfio.digital_write(3,0) #turn off
pfio.digital_write(4,0) #turn off
pfio.digital_write(5,0) #turn off
pfio.digital_write(6,0) #turn off
def convert8(self):
print('EXIT PROGRAM')
my_pwm.stop()
quit()
def EventsPerTime(self):
global RPM, this_time, last_time
if GPIO.input(self) > 0.5:
this_time = time.time()
RPM = (1/(this_time - last_time))*30
last_time = this_time
#print 'RPM is %d' % RPM
GPIO.add_event_detect(18, GPIO.RISING, callback=EventsPerTime, bouncetime=3)
def Tach(self):
global RPM
if RPM > 1:
print 'RPM is %d' % RPM
self.TACHO.config(text=RPM)
root = Tk()
logo2 = PhotoImage(file="/home/pi/Off LED.gif")
logo = PhotoImage(file="/home/pi/Red LED.gif")
root.wm_title('FAN PWM Control program')
app = App(root)
root.mainloop()
您已有一个获取当前 RPM 的函数。最简单的事情就是在那里更新标签：
def EventsPerTime(self):
global RPM, this_time, last_time
if GPIO.input(self) > 0.5:
...
RPM = (1/(this_time - last_time))*30
...
self.TACHO.configure(text=RPM)
问题的另一部分是您错误地指定了回叫。您需要更改此代码：
GPIO.add_event_detect(..., callback=EventsPerTime, ...)
对此：
GPIO.add_event_detect(..., callback=self.EventsPerTime, ...)
您还必须重新定义 EventsPerTIme 以接受附加参数：
def EventsPerTime(self, channel):
...
以下是我 Raspberry Pi 上显示 RPM 的 PWM GUI 控件的代码更改。由于良好的反馈和通过此 post 和网站提供的帮助，我设法获得了程序 运行 并实现了我的目标。该代码可能没有达到应有的水平或效率，因此请随时提供改进建议。
感谢您的帮助和分享知识。
#self.button9 = Button(frame, text='Display RPM', command=self.Tach) Stopped using this button
#self.button9.grid(row=11, column=0) Stopped using this button
self.TimerInterval = 500 #This sets the time interval between RPM readings
self.Tach() #This will start the 'Tach' method when the GUI starts
def convert0(self):
我还为 'Tach' 编写了一个方法，该方法使用 'after' 函数，该函数将在设定的时间间隔后调用给定的函数。所以我将它设置为每 500 毫秒调用一次。
def Tach(self):
print 'RPM is %d' % RPM
self.TACHO.config(text='RPM is %d' % RPM)
self.master.after(self.TimerInterval,self.Tach) #Used 'after' to repeat this method at the time interval
我还不确定如何停止 'after' 函数，但我会着手解决这个问题并一路学习。