1  # SPDX-FileCopyrightText: 2021 Kattni Rembor for Adafruit Industries
 2  # SPDX-License-Identifier: MIT
 3  """
 4  CircuitPython I2S Tone playback example.
 5  Plays a tone for one second on, one
 6  second off, in a loop.
 7  
 8  Remove this line and all of the following docstring content before submitting to the Learn repo.
 9  
10  Update the three I2S pins to match the wiring chosen for the microcontroller. If you are unsure of
11  a proper I2S pin combination, run the pin combination script found here:
12  https://adafru.it/i2s-pin-combo-finder
13  
14  Update the following pin names to a viable pin combination:
15  * BIT_CLOCK_PIN
16  * WORD_SELECT_PIN
17  * DATA_PIN
18  """
19  import time
20  import array
21  import math
22  import audiocore
23  import board
24  import audiobusio
25  
26  audio = audiobusio.I2SOut(board.BIT_CLOCK_PIN, board.WORD_SELECT_PIN, board.DATA_PIN)
27  
28  tone_volume = 0.1  # Increase this to increase the volume of the tone.
29  frequency = 440  # Set this to the Hz of the tone you want to generate.
30  length = 8000 // frequency
31  sine_wave = array.array("h", [0] * length)
32  for i in range(length):
33      sine_wave[i] = int((math.sin(math.pi * 2 * i / length)) * tone_volume * (2 ** 15 - 1))
34  sine_wave_sample = audiocore.RawSample(sine_wave)
35  
36  while True:
37      audio.play(sine_wave_sample, loop=True)
38      time.sleep(1)
39      audio.stop()
40      time.sleep(1)