from machine import Pin, PWM, ADC       #引入module:machine，在此只引入"Pin,PWM,ADC"功能
import time                             #引入module:time
ledpin = Pin(20,Pin.OUT)
adcpin = ADC(14)
LED = PWM(ledpin)

while True:
    ADC_value = (adcpin.read()/4)
    print("Now read ADC Voltage is,", str(ADC_value))
    
    LED.duty(int(ADC_value))
    time.sleep_ms(50)