from machine import Pin, ADC    
from time import sleep


adc = ADC(Pin(28))
led3 = Pin(16, Pin.OUT)


while True:
    analog_value = adc.read_u16()
    print(f"Analog value: {analog_value}")

    voltage = analog_value * (3.3 / 65535)
    print(f"Voltage: {voltage}")

    print("==========")
    sleep(1)
    brightness = voltage
    led3.value(brightness)