Python • Re: Program to blink 3 LEDs

Hi, I have created a program to blink 3 LED's in sequence. Im just sure if the hardware button is faulty or not. Can anyone share their views on the code?

Code:

import RPi.GPIO as GPIOimport timeLED1 = 16LED2 = 20LED3 = 21BUTTON = 13GPIO.setmode(GPIO.BCM)GPIO.setup(LED1, GPIO.OUT)GPIO.setup(LED2, GPIO.OUT)GPIO.setup(LED3, GPIO.OUT)GPIO.setup(BUTTON, GPIO.IN, pull_up_down = GPIO.PUD_DOWN)while True:    for x in range(0,3):        while GPIO.input(BUTTON) == GPIO.LOW:            pass        if GPIO.input(BUTTON) == GPIO.HIGH and x == 0:            GPIO.output(LED1,GPIO.HIGH)            GPIO.output(LED2,GPIO.LOW)            GPIO.output(LED3,GPIO.LOW)            while GPIO.input(BUTTON) == GPIO.HIGH:                pass            while GPIO.input(BUTTON) == GPIO.LOW:                pass        elif GPIO.input(BUTTON) == GPIO.HIGH and x == 1:            GPIO.output(LED1,GPIO.LOW)            GPIO.output(LED2,GPIO.HIGH)            GPIO.output(LED3,GPIO.LOW)            while GPIO.input(BUTTON) == GPIO.HIGH:                pass            while GPIO.input(BUTTON) == GPIO.LOW:                pass        elif GPIO.input(BUTTON) == GPIO.HIGH and x == 2:            GPIO.output(LED1,GPIO.LOW)            GPIO.output(LED2,GPIO.LOW)            GPIO.output(LED3,GPIO.HIGH)            while GPIO.input(BUTTON) == GPIO.HIGH:               pass            while GPIO.input(BUTTON) == GPIO.LOW:               pass            GPIO.output(LED3,GPIO.LOW)

" Im just sure if the hardware button is faulty or not. "

What is the reason for your uncertainty?

How is the button/switch cabled to your RPi board?

Perhaps add some Python print() statements to your script to track progress of execution for diagnostic/debugging purposes.

Maybe the script is working correctly but you never perceive an LED being turned on because it is turned off again very quickly?

You use this code fragment 3 times -

Code:

            while GPIO.input(BUTTON) == GPIO.HIGH:                pass            while GPIO.input(BUTTON) == GPIO.LOW:                pass

What is its purpose?

There seems to be some redundancy here -

Code:

        while GPIO.input(BUTTON) == GPIO.LOW:            pass        if GPIO.input(BUTTON) == GPIO.HIGH and x == 0:

If you are no longer in a loop because the Button is now not held Low, won't the Button inevitably be High?

Statistics: Posted by B.Goode — Thu May 23, 2024 1:52 pm