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中计算出RPM。 GUI的顶部有一个标签，用于选择不同工作周期的按钮，用于显示选择了哪个按钮的LED徽标指示器，用于“停止风扇”，“退出”按钮的按钮，＆＃ 39;显示RPM＆＃39;。
我使用＆＃39; Start Fan＆＃39;按钮。然后我可以选择不同的工作周期。当我点击“显示RPM＆＃39;按钮GUI顶部的标签显示RPM（小数点后面有很多数字），它只是RPM的快照。我的代码运行正常。
我的问题是这个。如何让标签不断显示变化的RPM？我想删除＆＃39;显示RPM＆＃39;按钮，让标签始终显示实时变化的RPM。 我已经用Google搜索了几个小时的帮助，并且已经尝试了“＃，”，“＃39”等函数调用等等。但我似乎无法掌握我需要做什么或在哪里做应该去的代码。
非常感谢您的时间和帮助。 代码可能不是我所知道的最好的，但我在学习。我很乐意接受任何关于如何改进的建议。
# 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()
答案 0 :(得分：1)
您已拥有获取当前RPM的功能。最简单的方法是在那里更新标签：
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, ...)
到此：
GPIO.add_event_detect(..., callback=self.EventsPerTime, ...)
您还必须重新定义EventsPerTIme以接受其他参数：
def EventsPerTime(self, channel):
...
答案 1 :(得分：0)
以下是我在Raspberry Pi上显示RPM的PWM GUI控件的代码更改。由于通过这篇文章和网站提供的良好反馈和帮助，我设法让程序运行并实现我的目标。代码可能没有尽可能好或高效，所以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＆＃39;”写了一个方法。使用＆＃39;之后＆＃39;在设定的间隔后调用给定函数的函数。所以我把它设置为每500mS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
我不确定如何停止＆＃39;之后＆＃39;功能还没有，但我会在那里学习并学习。