Buzzer.py

"""
# Buzzer.py - Object-oriented implementation of active and passive buzzers
# Author: Arijit Sengupta
"""

import time
from machine import Pin, PWM
from Log import *

class Buzzer:
    """
    A simple buzzer class - use it to play and pause different sounds
    ranging from fequencies 10 through 10000
    default volume is half volume - set it between 0 and 10
    """
    
    def __init__(self, pin, name='Buzzer'):
        """
        Base class init - we don't do anything with the pin here
        """
        
        self._name = name
        
    def beep(self, tone=500, duration=150):
        """
        Beep the buzzer with the given tone for duration ms
        """
        
        Log.i(f"Beeping {self._name} at {tone}hz for {duration} ms")
        self.play(tone)
        time.sleep(duration / 1000)
        self.stop()

    def play(self, tone=500):
        """ Stub for playing a tone - implemented in subclasses """
        pass
    
    def stop(self):
        """ Stub for stopping - implemented in subclasses """
        pass
    
class ActiveBuzzer(Buzzer):
    """
    An active buzzer has an internal oscillator that plays a fixed tone when power is applied
    Cannot control the tone. Only turn on and off.
    """
    
    def __init__(self, pin, name='Buzzer'):
        super().__init__(pin, name)
        self._buz = Pin(pin, Pin.OUT)
   
    def play(self, tone=500):
        """ Play sound. Tone is ignored. """
        
        Log.i(f"Start playing {self._name}")
        self._buz.value(1)
        
    def stop(self):
        """ Stop the sound. """
        
        Log.i(f"Stop playing {self._name}")
        self._buz.value(0)
    
class PassiveBuzzer(Buzzer):
    """
    A passive buzzer does not have an internal oscillator. MC needs to send a PWM signal
    to play tones. The tone is controlled by the frequency of the PWM, and the volume level
    is controlled by the duty cycle. Setting duty cycle to 0 stops sound.
    """
    MAX = 32767  # Max value for duty cycle
    
    def __init__(self, pin, name='Buzzer'):
        Log.i("PassiveBuzzer: constructor")
        super().__init__(pin, name)
        self._buz = PWM(Pin(pin))
        self._volume = 0.5  # Default volume is half
        self._playing = False
        self.stop()

    def play(self, tone=500):
        """ play the supplied tone. """
        
        Log.i(f"{self._name}: playing tone {tone}")
        self._buz.freq(tone)
        self._buz.duty_u16(int(self._volume * self.MAX))
        self._playing = True

    def stop(self):
        """ Stop playing sound """
        
        Log.i(f"{self._name}: stopping tone")
        self._buz.duty_u16(0)
        self._playing = False

    def setVolume(self, volume=0.5):
        """ 
        Change the volume of the sound currently playing and future plays.
        Volume is between 0 and 1.

        Volume 0 is silent, volume 1 is max volume. Note that this is not a linear
        and towards the lower end, the sound drops off quickly. At the higher end,
        the sound increases slowly, and might only be noticeable when volume is
        set to max.
        """
        
        Log.i(f"{self._name}: changing volume to {volume}")
        self._volume = volume
        if (self._playing):
            self._buz.duty_u16(int(self._volume * self.MAX))

# Known tones from https://github.com/james1236/buzzer_music
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
}

# Some basic do re mi tones
DO = tones['C4']
RE = tones['D4']
MI = tones['E4']
FA = tones['F4']
SO = tones['G4']
LA = tones['A4']
TI = tones['B4']
DO2 = tones['C5']


### The following code is for testing purposes only
### To use this code, add an Active Buzzer on Pin 14
### and a Passive Buzzer on Pin 15 Then run the module directly

if __name__ == "__main__":
    Log.i("Testing Active Buzzer")
    active_buzzer = ActiveBuzzer(14, "TestActiveBuzzer")
    active_buzzer.play()
    time.sleep(1)
    active_buzzer.stop()
    
    Log.i("Testing Passive Buzzer")

    buzzer = PassiveBuzzer(16, "TestBuzzer")
    buzzer.play(DO)
    time.sleep(1)
    buzzer.stop()
    
    buzzer.setVolume(0.2)
    buzzer.play(RE)
    time.sleep(1)
    buzzer.stop()
    
    buzzer.setVolume(0)
    buzzer.play(MI)  # Should not sound
    time.sleep(1)
    buzzer.stop()
    
    # Test volume change
    Log.i("Testing volume change")
    for v in range(0, 11):
        buzzer.setVolume(v / 10)
        buzzer.play(FA)
        time.sleep(0.5)
   
    # Play do re mi
    Log.i("Playing Do Re Mi")
    buzzer.setVolume(0.5)

    for note in [DO, RE, MI, FA, SO, LA, TI, DO2]:
        buzzer.play(note)
        time.sleep(0.5)

    buzzer.stop()