Play sine wave audio use I2S.

[water5]

CircuitPython example

import time, array, math, audiocore, board, audiobusio

sample_rate = 8000
tone_volume = .7
frequency = 440
length = sample_rate // frequency
sine_wave = array.array("H", [0] * length)
for i in range(length):
	sine_wave[i] = int((math.sin(math.pi * 2 * frequency * i / sample_rate) * tone_volume + 1) * (2 ** 15 - 1))

audio = audiobusio.I2SOut(board.D14, board.D13, board.D12)
sine_wave_sample = audiocore.RawSample(sine_wave, sample_rate = sample_rate)
while True:
	audio.play(sine_wave_sample, loop = True)
	time.sleep(1)
	audio.stop()
	time.sleep(1)

On Micropython, refer https://github.com/miketeachman/micropython-esp32-i2s-examples, play audio samples from an I2S microphone module, and Play audio samples through a speaker using an I2S amplifier module.

Read audio samples from an I2S microphone module

from machine import I2S
from machine import Pin

bck_pin = Pin(14)  # Bit clock output
ws_pin = Pin(13)   # Word clock output
sdin_pin = Pin(12) # Serial data input

audio_in = I2S(I2S.NUM0,                                 # create I2S peripheral to read audio
               bck=bck_pin, ws=ws_pin, sdin=sdin_pin,    # sample data from an INMP441
               standard=I2S.PHILIPS, mode=I2S.MASTER_RX, # microphone module 
               dataformat=I2S.B32,                       
               channelformat=I2S.RIGHT_LEFT,
               samplerate=16000, 
               dmacount=16,dmalen=256)
               
samples = bytearray(2048)                                # bytearray to receive audio samples

num_bytes_read = audio_in.readinto(samples)              # read audio samples from microphone
                                                         # note:  blocks until sample array is full
                                                         # - see optional timeout argument
                                                         # to configure maximum blocking duration       

Play audio samples through a speaker using an I2S amplifier module

from machine import I2S
from machine import Pin

bck_pin = Pin(14)   # Bit clock output
ws_pin = Pin(13)    # Word clock output
sdout_pin = Pin(12) # Serial data output

audio_out = I2S(I2S.NUM1,                                  # create I2S peripheral to write audio
                bck=bck_pin, ws=ws_pin, sdout=sdout_pin,   # sample data to an Adafruit I2S Amplifier
                standard=I2S.PHILIPS, mode=I2S.MASTER_TX,  # breakout board, 
                dataformat=I2S.B16,                        # based on MAX98357A device
                channelformat=I2S.ONLY_RIGHT,
                samplerate=16000, 
                dmacount=16,dmalen=512)
               
samples = bytearray(1024)                                 # bytearray containing audio samples to transmit

num_bytes_written = audio_out.write(samples)              # write audio samples to amplifier
                                                          # note:  blocks until sample array is emptied
                                                          # - see optional timeout argument
                                                          # to configure maximum blocking duration

Can I play sine wave on MicroPython likes CircuitPython example? how generate this sine wave audio example bytearray on MicroPython?

[mattytrentini]

Yes, and it's conceptually the same. In fact, in the examples you linked to there's play_tone.py that does what you're looking for.

Effectively: Fill the sample buffer with data created from a sine wave before playing it (just like in the CircuitPython example).

[Josverl]

The original Esp32 also has a programmable (co)sine pheriphial that can be used via the DAC.
It's not directly exposed, but simple to use, and distortion free even under asyncio workloads through this class.

Not I2S though
See https://github.com/Josverl/beeper-now/blob/main/src%2Fesp32_cosine%2Freadme.md

[mattytrentini]

Oh, handy! Shame so many of the newer ESP32 devices don't have DAC support...