from machine import Pin,PWM
import time
pin=Pin(25, Pin.OUT)

def tone(pin,pitch):
      pin.on()
      time.sleep_us(pitch)
      pin.off()
      time.sleep_us(pitch)

while True:
  tone(pin,12860)    
      
#   pin.on()
#   time.sleep_ms(20)
#   pin.off()
#   time.sleep_ms(20)