import time
import digitalio
import board
import pwmio

buzzer = pwmio.PWMOut(board.GP27, variable_frequency=True)

taster = digitalio.DigitalInOut(board.GP28)
taster.direction = digitalio.Direction.INPUT
taster.pull = digitalio.Pull.DOWN

OFF = 0
ON = 2**15

buzzer.frequency = 440

while True:
    if taster.value:
        buzzer.duty_cycle = ON
        time.sleep(0.1)
    else:
        buzzer.duty_cycle = OFF
        time.sleep(0.1)