buzzer.py

# Copyright @ 20023, Adrian Blakey. All rights reserved
# The pushme/pullme buzzer on pins 20/21

from machine import Pin, PWM, mem32
from utime import sleep
import logging

log = logging.getLogger("buzzer")

tones = {
"B0": 31,
"C1": 33,
"CS1": 35,
"D1": 37,
"DS1": 39,
"E1": 41,
"F1": 44,
"FS1": 46,
"G1": 49,
"GS1": 52,
"A1": 55,
"AS1": 58,
"B1": 62,
"C2": 65,
"CS2": 69,
"D2": 73,
"DS2": 78,
"E2": 82,
"F2": 87,
"FS2": 93,
"G2": 98,
"GS2": 104,
"A2": 110,
"AS2": 117,
"B2": 123,
"C3": 131,
"CS3": 139,
"D3": 147,
"DS3": 156,
"E3": 165,
"F3": 175,
"FS3": 185,
"G3": 196,
"GS3": 208,
"A3": 220,
"AS3": 233,
"B3": 247,
"C4": 262,
"CS4": 277,
"D4": 294,
"DS4": 311,
"E4": 330,
"F4": 349,
"FS4": 370,
"G4": 392,
"GS4": 415,
"A4": 440,
"AS4": 466,
"B4": 494,
"C5": 523,
"CS5": 554,
"D5": 587,
"DS5": 622,
"E5": 659,
"F5": 698,
"FS5": 740,
"G5": 784,
"GS5": 831,
"A5": 880,
"AS5": 932,
"B5": 988,
"C6": 1047,
"CS6": 1109,
"D6": 1175,
"DS6": 1245,
"E6": 1319,
"F6": 1397,
"FS6": 1480,
"G6": 1568,
"GS6": 1661,
"A6": 1760,
"AS6": 1865,
"B6": 1976,
"C7": 2093,
"CS7": 2217,
"D7": 2349,
"DS7": 2489,
"E7": 2637,
"F7": 2794,
"FS7": 2960,
"G7": 3136,
"GS7": 3322,
"A7": 3520,
"AS7": 3729,
"B7": 3951,
"C8": 4186,
"CS8": 4435,
"D8": 4699,
"DS8": 4978
}


global the_buzzer
class Buzzer():
    def __init__(self):
        self._cha = PWM(Pin(20), duty_u16=32768, freq=1000)
        self._chb = PWM(Pin(21), duty_u16=32768)
        # Set PWM frequency to 1 kHz.
        # I'll be the same for both channels.
        # Set duty to 50% on both channels.
        # Both channels must have same duty cycle for this to work.
        # From 4.5.2 in https://datasheets.raspberrypi.com/rp2040/rp2040-datasheet.pdf
        # 20/21 are PWM2A and PWM2B
        # Invert output B on slice 2 - GP21.
        mem32[0x40050000 + 0x14 * 2 + 0x2000] = 1 << 3 # invert=True causes a 'flutter'
        
    def playtone(self, freq):
        self._cha.freq(freq)
        mem32[0x40050000 + 0x14 * 2 + 0x2000] = 1 << 3
        
    def bequiet(self):
        self._cha.freq(10)
        
    def playsong(self, mysong):
        for i in range(len(mysong)):
            if (mysong[i] == "P"):
                self.bequiet()
            else:
                self.playtone(tones[mysong[i]])
            sleep(0.3)
        self._cha.deinit()
        self._chb.deinit()
           
try:
    the_buzzer
except NameError:
    log.debug('the_buzzer not yet defined')
    the_buzzer = Buzzer()
        
song = ["E5","G5","A5","P","E5","G5","B5","A5","P","E5","G5","A5","P","G5","E5"]

the_buzzer.playsong(song)