from machine import Pin, PWM, ADC
from time import sleep
sleep (0.1)
print ("begin")

servoPin = PWM(Pin(28))
# даёт сигнал каждые 20 мс, т.е. 50 Гц
servoPin.freq(50)
pot = ADC(Pin(26))

def servo(degrees):
    # limit degrees beteen 0 and 180
    if degrees > 180: degrees=180
    if degrees < 0: degrees=0
    # set max and min duty
    maxDuty=9000
    minDuty=1000
    # new duty is between min and max duty in proportion to its value
    koeff = (maxDuty-minDuty) / 180
    newDuty=minDuty+ koeff * degrees
    # servo PWM value is set
    servoPin.duty_u16(int(newDuty))

while True:
    potValue = pot.read_u16()
    angle = int(potValue * 180 / 65535)
    print(potValue, angle)
    servo(angle)
    sleep (0.2)