​# 2g-RGB-LED-GUI.py
# 2020-06-20 revised for common anode configure option
# use GUI sliders to control LEDs
# to install guizero: $ pip3 install guizero
from guizero import App, Slider, Text
from gpiozero import PWMLED
#import time

# define methods to change LED brightness
def update_red(duty):
    red.value = (float(duty)/100)
    # change the led brightness to match the slider

def update_green(duty):
    green.value = (float(duty)/100)
    
def update_blue(duty):
    blue.value = (float(duty)/100)

# Configure the GPIO pins
red=PWMLED(24,False)    # False because common anode
green=PWMLED(23,False)
blue=PWMLED(18,False)

# Start Pulse Width Modulation (PWM) on the red, green and blue channels 
red.value = 0       # start at minimum brightness
green.value = 0
blue.value = 0

# create GUI and name it app
app = App(title='RGB LED Control', layout='grid')

# create labels for sliders and text
red_label = Text(app, text='Red', grid=[0,0])
green_label = Text(app, text='Green', grid=[0,1])
blue_label = Text(app, text='Blue', grid=[0,2])
stop_label = Text(app, text='use ther upper right X to stop script', grid=[0,3,2,1])

# create sliders
red_scale = Slider(app, grid=[1,0], command=update_red)
green_scale = Slider(app, grid=[1,1], command=update_green)
blue_scale = Slider(app, grid=[1,2], command=update_blue)

#size and position the GUI
app.tk.geometry("300x200+300+300")

# display the sliders and get values
try:
    app.display()
finally:  
    print("Cleaning up")
    red.value = 0       # turn off LED when exiting
    green.value = 0
    blue.value = 0