from machine import Pin, PWM
from time import sleep

servo = PWM(Pin(2), freq=50, duty=0)

def theta_to_duty(θ):
    duty = (1023 * ((2 * θ / 180) + 0.5)) / 20
    return duty

def Servo(theta):
    servo.duty(int(theta_to_duty(theta)))

while True:
    Servo(0)
    sleep(1)
    Servo(45)
    sleep(1)
    Servo(90)
    sleep(1)
    Servo(135)
    sleep(1)
    Servo(180)
    sleep(1)