Servo

from microbit import *

pin0.set_analog_period(15)

while True:

    if button_a.is_pressed():

        pin0.write_analog(1)

        sleep(1000)

        pin0.write_analog(90)

        sleep(1000)

        pin0.write_analog(170)

        sleep(1000)

        pin0.write_analog(1)

        sleep(1000)