import machine
import time
speaker=machine.PWM(machine.Pin(15))
speaker.duty_u16(int(65535/2))
speaker.freq(300)
time.sleep(1)
speaker.freq(500)
time.sleep(1)
speaker.freq(244)
time.sleep(1)
speaker.freq(280)
time.sleep(1)
speaker.freq(277)
time.sleep(1)
speaker.freq(293)
time.sleep(1)
speaker.freq(311)
time.sleep(1)
speaker.freq(329)
speaker.duty_u16(0)