from machine import Pin, PWM
from time import sleep

led = PWM(Pin(2), freq=1000)  # Initialize PWM on GPIO 2 at 1 kHz
button = Pin(18, Pin.IN, Pin.PULL_UP)  # Button with internal pull-up resistor

# Track current duty cycle
current_duty_cycle = 0  

while True:
  # Increase brightness
  for duty_cycle in range(current_duty_cycle, 1024, 10):  
    if button.value() == 0:  # Check if button is pressed
      break  # Exit loop if button is pressed
    led.duty(duty_cycle)
    current_duty_cycle = duty_cycle  # Update current duty cycle
    sleep(0.01)

  # Decrease brightness
  for duty_cycle in range(current_duty_cycle, -1, -10):  
    if button.value() == 0:  # Check if button is pressed
      break  # Exit loop if button is pressed
    led.duty(duty_cycle)
    current_duty_cycle = duty_cycle  # Update current duty cycle
    sleep(0.01)