[Solved] Identify the error in this code that controls LED brightness and fix it:import RPi.GPIO as GPIO GPIO.setmode(GPIO.BCM) GPIO.setup(18, GPIO.OUT) pwm = GPIO.PWM(18, 1000) pwm.ChangeDutyCycle(50) pwm.... | Raspberry Pi

Raspberry Pi - PWM Output

Identify the error in this code that controls LED brightness and fix it:

import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(18, GPIO.OUT)
pwm = GPIO.PWM(18, 1000)
pwm.ChangeDutyCycle(50)
pwm.start(50)
GPIO.cleanup()

AFrequency 1000 is too high, use 100

BChangeDutyCycle called before start; swap their order

CGPIO.cleanup() should be before pwm.start()

DMissing GPIO.setwarnings(False)

Step-by-Step Solution

Solution:

Step 1: Check PWM start and ChangeDutyCycle order
ChangeDutyCycle must be called after pwm.start(), not before.
Step 2: Correct the order
Swap lines so pwm.start(50) comes before pwm.ChangeDutyCycle(50).
Final Answer:
ChangeDutyCycle called before start; swap their order -> Option B
Quick Check:
start() must come before ChangeDutyCycle() [OK]

Quick Trick: Always start PWM before changing duty cycle [OK]

Common Mistakes:

Master "PWM Output" in Raspberry Pi

9 interactive learning modes - each teaches the same concept differently

More Raspberry Pi Quizzes

Identify the error in this code that controls LED brightness and fix it: