background music

music.py

from pybricks.hubs import InventorHub
from pybricks.pupdevices import Motor, ColorSensor, UltrasonicSensor
from pybricks.parameters import Port, Stop, Color, Button
from pybricks.tools import wait, StopWatch

JINGLE_BELLS = (
    ["B3/4", "B3/4", "B3/2"] * 2 + ["B3/4", "D4/4", "G3/4.", "A3/8", "B3/2.", "R/4"] +
    ["C4/4", "C4/4", "C4/4.", "C4/8", "C4/4", "B3/4", "B3/4", "B3/8", "B3/8",
     "D4/4", "D4/4", "C4/4", "A3/4", "G3/2.", "R/4"]
)

hub = InventorHub()

def play_note(note, duration):
    # needs some padding so we don't get StopIteration when calling next(note)
    note = iter(note + "\0")
    
    # Note names can be A-G followed by optional # (sharp) or b (flat) or R for rest
    c = next(note)
    if c == 'C':
        c = next(note)
        if c == 'b':
            raise ValueError("Cb is not allowed")
        elif c == '#':
            c = next(note)
            freq = 17.32
        else:
            freq = 16.35
    elif c == 'D':
        c = next(note)
        if c == 'b':
            c = next(note)
            freq = 17.32
        elif c == '#':
            c = next(note)
            freq = 19.45
        else:
            freq = 18.35
    elif c == 'E':
        c = next(note)
        if c == 'b':
            c = next(note)
            freq = 19.45
        elif c == '#':
            raise ValueError("E# is not allowed")
        else:
            freq = 20.60
    elif c == 'F':
        c = next(note)
        if c == 'b':
            raise ValueError("Fb is not allowed")
        elif c == '#':
            c = next(note)
            freq = 23.12
        else:
            freq = 21.83
    elif c == 'G':
        c = next(note)
        if c == 'b':
            c = next(note)
            freq = 23.12
        elif c == '#':
            c = next(note)
            freq = 25.96
        else:
            freq = 24.50
    elif c == 'A':
        c = next(note)
        if c == 'b':
            c = next(note)
            freq = 25.96
        elif c == '#':
            c = next(note)
            freq = 29.14
        else:
            freq = 27.50
    elif c == 'B':
        c = next(note)
        if c == 'b':
            c = next(note)
            freq = 29.14
        elif c == '#':
            raise ValueError("B# is not allowed")
        else:
            freq = 30.87
    elif c == 'R':
        c = next(note)
        freq = 0.0
    else:
        raise ValueError("Missing note name A-G or R")
        
    # Note name must be followed by the octave number
    if freq:
        octave = ord(c) - ord('0')
        c = next(note)
        if octave < 2 or octave > 8:
            raise ValueError("Missing octave number 2-8")
        freq *= 2 << (octave - 1)
        
    # '/' delimiter is required between octave and fraction
    if c != '/':
        raise ValueError("Missing /")
        
    c = next(note)
        
    # The fractional size of the note, e.g. 4 = quarter note
    fraction = ord(c) - ord('0')
    c = next(note)
    if fraction < 0 or fraction > 9:
        raise ValueError("Missing fractional value 1, 2, 4, 8, etc.")
          
    # optional second digit 
    fraction2 = ord(c) - ord('0')
    if 0 <= fraction2 <= 9:
        c = next(note)
        fraction = fraction * 10 + fraction2
        
    duration /= fraction
    
    # optional decorations
    
    if c == '.':
        c = next(note)
        duration = 3 * duration / 2
        
    release = True
    
    if c == '_':
        c = next(note)
        release = False
        
    hub.speaker.beep(freq, -1)
    
    if release:
        full_duration = duration
        duration = 7 * duration / 8
    
    timer = StopWatch()
    while timer.time() < duration:
        yield
        
    if release:
        hub.speaker.beep(0, -1)
        while timer.time() < full_duration:
            yield

def play_notes(notes, tempo=120):
    duration = 4 * 60 * 1000 / tempo
    try:
        for n in notes:
            yield from play_note(n, duration)
    finally:
        hub.speaker.beep(0, -1)
    

music = play_notes(JINGLE_BELLS, tempo=140)

while True:
    try:
        next(music)
    except StopIteration:
        pass
    wait(10)