from machine import Pin, PWM
import utime

buzzer = PWM(Pin(20))

def tone(pin, freq, duration):
    if freq == 0:
        pin.duty_u16(0)
        utime.sleep_ms(duration)
        return
    pin.freq(freq)
    pin.duty_u16(30000)
    utime.sleep_ms(duration)
    pin.duty_u16(0)
    utime.sleep_ms(50)  # 余韻の間

# スーパーマリオBGM（周波数, 長さ[ms]）
melody = [
    (660, 100), (660, 100), (0, 200), (660, 100),
    (0, 200), (520, 100), (660, 100), (0, 200),
    (770, 100), (0, 500), (380, 100)
]

# 演奏処理
for note, duration in melody:
    tone(buzzer, note, duration)