Python PWM GUI example on a Raspberry PI

In this example we create a GUI to set the value for our PWM example – Controlling the Brightness of an LED

Schematics

Parts

Code

Save this as pwmgui.py

[codesyntax lang=”python”]

from Tkinter import *
import RPi.GPIO as GPIO
import time

GPIO.setmode(GPIO.BCM)
GPIO.setup(18, GPIO.OUT)
pwm = GPIO.PWM(18, 500)
pwm.start(100)

class App:
	def __init__(self, master):
		frame = Frame(master)
		frame.pack()
		scale = Scale(frame, from_=0, to=100, orient=HORIZONTAL, command=self.update)
		scale.grid(row=0)

	def update(self, duty):
		pwm.ChangeDutyCycle(float(duty))
		
root = Tk()
root.wm_title('PWM Example')
app = App(root)
root.geometry("200x50+0+0")
root.mainloop()

[/codesyntax]

Testing

Run the following by the typing in

sudo python pwmgui.py