Build a Light Theremin Using Maker Pi Pico and CircuitPython

code.py

#
# Build a Light Theremin Using Raspberry Pi Pico
# (Maker Pi Pico) and CircuitPython
#
# Raspberry Pi Pico
# - [Maker Pi Pico] https://my.cytron.io/p-maker-pi-pico?tracking=idris
# Grove - Light Sensor v1.2
# - https://my.cytron.io/p-grove-light-sensor-v1.2?tracking=idris
#
# Update:
# 9 Feb 2021 - Tested with CircuitPython Pico 6.2.0-beta.1-127-ga10ce39ae
# 

from time import sleep
from board import *
from digitalio import DigitalInOut, Direction, Pull
from analogio import AnalogIn
from pwmio import PWMOut
from pitches import tones
from neopixel_write import neopixel_write

sleep(1)

btn1 = DigitalInOut(GP20)
btn1.direction = Direction.INPUT
btn1.pull = Pull.UP

btn2 = DigitalInOut(GP21)
btn2.direction = Direction.INPUT
btn2.pull = Pull.UP

btn3 = DigitalInOut(GP22)
btn3.direction = Direction.INPUT
btn3.pull = Pull.UP

pixel_off = bytearray([0, 0, 0])
pixel_red = bytearray([0, 20, 0])
pixel_green = bytearray([20, 0, 0])
pixel_blue = bytearray([0, 0, 20])
rgb = DigitalInOut(GP28)
rgb.direction = Direction.OUTPUT
neopixel_write(rgb, pixel_off)

light = AnalogIn(GP27)

tempo = 1
melody_start = ['c4', 'g4']
rhythm_start = [8, 8]

def playTone(melody, rhythm):
    for tone, length in zip(melody, rhythm):
        beeper = PWMOut(GP18, variable_frequency=True)
        if tones[tone] != 0:
            beeper.duty_cycle = 2 ** 15
            beeper.frequency = tones[tone]
        sleep(tempo / length)
        beeper.deinit()

def map(x, in_min, in_max, out_min, out_max):
    if x > in_max:
        x = in_max
    if x < in_min:
        x = in_min
    return (x-in_min) * (out_max-out_min) / (in_max-in_min) + out_min

playTone(melody_start, rhythm_start)

while btn1.value:
    pass

notes_theremin = [
    'c3', 'cs3', 'd3', 'ds3', 'e3', 'f3', 'fs3', 'g3', 'gs3', 'a3', 'as3', 'b3',
    'c4', 'cs4', 'd4', 'ds4', 'e4', 'f4', 'fs4', 'g4', 'gs4', 'a4', 'as4', 'b4',
    'c5', 'cs5', 'd5', 'ds5', 'e5', 'f5', 'fs5', 'g5', 'gs5', 'a5', 'as5', 'b5',
    'c6', 'cs6', 'd6', 'ds6', 'e6', 'f6', 'fs6', 'g6', 'gs6', 'a6', 'as6', 'b6',
]

enable_theremin = False
delay = 0.2

while True:
    if not btn1.value:
        enable_theremin = not enable_theremin
        if enable_theremin:
            neopixel_write(rgb, pixel_green)
        else:
            neopixel_write(rgb, pixel_off)
        sleep(1)

    if enable_theremin:
        light_ADC = light.value
        note = int(map(light_ADC, 1000, 40000, 0, 47))
        print("ADC: {}\tMap: {}\t\tNote: {}".format(light_ADC, note, notes_theremin[note]))

        beeper = PWMOut(GP18, variable_frequency=True)
        beeper.duty_cycle = 2 ** 15
        beeper.frequency = tones[notes_theremin[note]]
        sleep(delay)
        beeper.deinit()
        sleep(0.01)

        if not btn2.value:
            neopixel_write(rgb, pixel_green)
            delay -= 0.01
            if delay < 0.1:
                neopixel_write(rgb, pixel_red)
                delay = 0.1
        elif not btn3.value:
            neopixel_write(rgb, pixel_green)
            delay += 0.01
            if delay > 0.2:
                delay = 0.2
                neopixel_write(rgb, pixel_blue)

pitches.py

tones = {
    '':    0,
    '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,
}