from machine import Pin,PWM,ADC

adc=ADC(Pin(32))
adc.width(ADC.WIDTH_9BIT)
adc.atten(ADC.ATTN_11DB)

pwm=PWM(Pin(5),freq=50)

while(1):
  v=adc.read()
  if(v<=127):
    pwm.duty(25)
  elif(v<=254):
    pwm.duty(50)
  elif(v<=381):
    pwm.duty(90)
  else:
    pwm.duty(125)