"""Program 2-8: Toggling GPIO16 pin at 440Hz"""

import time
from machine import Pin

buzz = Pin(16, Pin.OUT)
HALF_PERIOD = 1_000_000 // 2 // 440

while True:
    buzz.on()
    time.sleep_us(HALF_PERIOD)
    buzz.off()
    time.sleep_us(HALF_PERIOD)