buzzer_music.py

"""
Micropython (Raspberry Pi Pico)
Plays music written on onlinesequencer.net through a passive piezo buzzer.
Uses fast arpeggios with a single buzzer to simulate polyphony
Also supports multiple buzzers at once for real polyphony
https://github.com/james1236/buzzer_music
"""

from machine import Pin, PWM
from math import ceil

tones = {
    'C0':16,
    'C#0':17,
    'D0':18,
    'D#0':19,
    'E0':21,
    'F0':22,
    'F#0':23,
    'G0':24,
    'G#0':26,
    'A0':28,
    'A#0':29,
    'B0':31,
    'C1':33,
    'C#1':35,
    'D1':37,
    'D#1':39,
    'E1':41,
    'F1':44,
    'F#1':46,
    'G1':49,
    'G#1':52,
    'A1':55,
    'A#1':58,
    'B1':62,
    'C2':65,
    'C#2':69,
    'D2':73,
    'D#2':78,
    'E2':82,
    'F2':87,
    'F#2':92,
    'G2':98,
    'G#2':104,
    'A2':110,
    'A#2':117,
    'B2':123,
    'C3':131,
    'C#3':139,
    'D3':147,
    'D#3':156,
    'E3':165,
    'F3':175,
    'F#3':185,
    'G3':196,
    'G#3':208,
    'A3':220,
    'A#3':233,
    'B3':247,
    'C4':262,
    'C#4':277,
    'D4':294,
    'D#4':311,
    'E4':330,
    'F4':349,
    'F#4':370,
    'G4':392,
    'G#4':415,
    'A4':440,
    'A#4':466,
    'B4':494,
    'C5':523,
    'C#5':554,
    'D5':587,
    'D#5':622,
    'E5':659,
    'F5':698,
    'F#5':740,
    'G5':784,
    'G#5':831,
    'A5':880,
    'A#5':932,
    'B5':988,
    'C6':1047,
    'C#6':1109,
    'D6':1175,
    'D#6':1245,
    'E6':1319,
    'F6':1397,
    'F#6':1480,
    'G6':1568,
    'G#6':1661,
    'A6':1760,
    'A#6':1865,
    'B6':1976,
    'C7':2093,
    'C#7':2217,
    'D7':2349,
    'D#7':2489,
    'E7':2637,
    'F7':2794,
    'F#7':2960,
    'G7':3136,
    'G#7':3322,
    'A7':3520,
    'A#7':3729,
    'B7':3951,
    'C8':4186,
    'C#8':4435,
    'D8':4699,
    'D#8':4978,
    'E8':5274,
    'F8':5588,
    'F#8':5920,
    'G8':6272,
    'G#8':6645,
    'A8':7040,
    'A#8':7459,
    'B8':7902,
    'C9':8372,
    'C#9':8870,
    'D9':9397,
    'D#9':9956,
    'E9':10548,
    'F9':11175,
    'F#9':11840,
    'G9':12544,
    'G#9':13290,
    'A9':14080,
    'A#9':14917,
    'B9':15804
}

#Time, Note, Duration, Instrument (onlinesequencer.net schematic format)
#0 D4 8 0;0 D5 8 0;0 G4 8 0;8 C5 2 0;10 B4 2 0;12 G4 2 0;14 F4 1 0;15 G4 17 0;16 D4 8 0;24 C4 8 0

class music:
    def __init__(self, songString='0 D4 8 0', looping=True, tempo=3, duty=2512, pin=None, pins=[Pin(0)]):
        self.tempo = tempo
        self.song = songString
        self.looping = looping
        self.duty = duty
        
        self.stopped = False
        
        self.timer = -1
        self.beat = -1
        self.arpnote = 0
        
        self.pwms = []
        
        if (not (pin is None)):
            pins = [pin]
        self.pins = pins
        for pin in pins:
            self.pwms.append(PWM(pin))
        
        self.notes = []

        self.playingNotes = []
        self.playingDurations = []


        #Find the end of the song
        self.end = 0
        splitSong = self.song.split(";")
        for note in splitSong:
            snote = note.split(" ")
            testEnd = round(float(snote[0])) + ceil(float(snote[2]))
            if (testEnd > self.end):
                self.end = testEnd
                
        #Create empty song structure
        while (self.end > len(self.notes)):
            self.notes.append(None)

        #Populate song structure with the notes
        for note in splitSong:
            snote = note.split(" ")
            beat = round(float(snote[0]));
            
            if (self.notes[beat] == None):
                self.notes[beat] = []
            self.notes[beat].append([snote[1],ceil(float(snote[2]))]) #Note, Duration


        #Round up end of song to nearest bar
        self.end = ceil(self.end / 8) * 8
    
    def stop(self):
        for pwm in self.pwms:
            pwm.deinit()
        self.stopped = True

    def restart(self):
        self.beat = -1
        self.timer = 0
        self.stop()
        self.pwms = []
        for pin in self.pins:
            self.pwms.append(PWM(pin))
        self.stopped = False

    def resume(self):
        self.stop()
        self.pwms = []
        for pin in self.pins:
            self.pwms.append(PWM(pin))
        self.stopped = False

    def tick(self):
        if (not self.stopped):
            self.timer = self.timer + 1
            
            #Loop
            if (self.timer % (self.tempo * self.end) == 0 and (not (self.timer == 0))):
                if (not self.looping):
                    self.stop()
                    return False
                self.beat = -1
                self.timer = 0
            
            #On Beat
            if (self.timer % self.tempo == 0):
                self.beat = self.beat + 1

                #Remove expired notes from playing list
                i = 0
                while (i < len(self.playingDurations)):
                    self.playingDurations[i] = self.playingDurations[i] - 1
                    if (self.playingDurations[i] <= 0):
                        self.playingNotes.pop(i)
                        self.playingDurations.pop(i)
                    else:
                        i = i + 1
                        
                #Add new notes and their durations to the playing list
                
                """
                #Old method runs for every note, slow to process on every beat and causes noticeable delay
                ssong = song.split(";")
                for note in ssong:
                    snote = note.split(" ")
                    if int(snote[0]) == beat:
                        playingNotes.append(snote[1])
                        playingDurations.append(int(snote[2]))
                """
                
                if (self.beat < len(self.notes)):
                    if (self.notes[self.beat] != None):
                        for note in self.notes[self.beat]:
                            self.playingNotes.append(note[0])
                            self.playingDurations.append(note[1])
                
                #Only need to run these checks on beats
                i = 0
                for pwm in self.pwms:
                    if (i >= len(self.playingNotes)):
                        if hasattr(pwm, 'duty_u16'):
                            pwm.duty_u16(0)
                        else:
                            pwm.duty(0)
                    else:
                        #Play note
                        if hasattr(pwm, 'duty_u16'):
                            pwm.duty_u16(self.duty)
                        else:
                            pwm.duty(self.duty)
                        pwm.freq(tones[self.playingNotes[i]])
                    i = i + 1
            

            #Play arp of all playing notes
            if (len(self.playingNotes) > len(self.pwms)):
                p = self.pwms[len(self.pwms)-1];
                if hasattr(p, 'duty_u16'):
                    p.duty_u16(self.duty)
                else:
                    p.duty(self.duty)
                
                if (self.arpnote > len(self.playingNotes)-len(self.pwms)):
                    self.arpnote = 0
                self.pwms[len(self.pwms)-1].freq(tones[self.playingNotes[self.arpnote+(len(self.pwms)-1)]])
                self.arpnote = self.arpnote + 1
                
            return True
        else:
            return False