test_pcm5102.py

# Test the I2S interface to a so-called PCM5102 audio board.
# by robcranfill
# based on:
#   SPDX-FileCopyrightText: 2018 Kattni Rembor for Adafruit Industries
#   SPDX-License-Identifier: MIT
# but tweaked for RP Pico

# Standard Python libs
import array
import math
import time

# Adafruit libs
import audiobusio
import audiocore
import board


tone_volume = 0.9   # Increase this to increase the volume of the tone.
frequency = 440     # Set this to the frequency, in Hz, of the tone you want to generate.

length = 8000 // frequency
sine_wave = array.array("h", [0] * length)
for i in range(length):
    sine_wave[i] = int((math.sin(math.pi * 2 * i / length)) * tone_volume * (2 ** 15 -1))

# Pico pinouts
#
# I2S clock: GP16 = Pico pin 21 -> "BCK" on board
PIN_BIT_CLOCK = board.GP16

# I2S LR clock (aka WS clock): GP17 = Pico pin 22 -> "LCK" on board
PIN_WORD_SELECT = board.GP17

# I2S data: GP18 = Pico pin 24 -> "DIN" on board
PIN_DATA = board.GP18

# NOTE: The PCM5102 board's "SCK" pin must be pulled to ground!


audio = audiobusio.I2SOut(bit_clock=PIN_BIT_CLOCK, word_select=PIN_WORD_SELECT, data=PIN_DATA)
sine_wave_sample = audiocore.RawSample(sine_wave)

print("Running....")
while True:
    print("boop!")
    audio.play(sine_wave_sample, loop=True)
    time.sleep(1)
    audio.stop()
    time.sleep(1)