from machine import Pin, PWM
import time

buzzer = PWM(Pin(4))

# Happy Birthday Melody Frequencies (in Hz)
melody = [264, 264, 294, 264, 349, 330, 264, 264, 294, 264, 392, 349, 264, 264, 264, 440, 349, 330, 294]
note_duration = 0.5

buzzer.duty(512)  # Duty cycle set to 50%
buzzer.freq(melody[0]) 

while True:
    for freq in melody:
        buzzer.freq(freq)     
        buzzer.duty(1023)    
        time.sleep(note_duration)  
        buzzer.duty(0)        
        time.sleep(0.1)