Simple I2S streaming code only works for sample rates <22050

notes:

• Using ESP32 and v1.21.0
• As for web.py I am using the great https://github.com/wybiral/micropython-aioweb
• As for queue.py I am using https://github.com/peterhinch/micropython-async/blob/master/v3/primitives/queue.py

from machine import I2S
from machine import Pin
import web
import asyncio 
from queue import Queue    
  
bck_pin = Pin(33)  # Bit clock output
ws_pin = Pin(32)   # Word clock output
sdin_pin = Pin(25) # Serial data input

au_chunk_len = 8192
au_chunks = 8 # must be power of 2

audio_in = I2S(1,                                 # create I2S peripheral to read audio
               sck=bck_pin, ws=ws_pin, sd=sdin_pin,    # sample data from an INMP441
               mode=I2S.RX,
               bits=32,
               format=I2S.MONO,
               rate=8000,
               ibuf=au_chunk_len)

sreader = asyncio.StreamReader(audio_in)

queue = Queue(au_chunks)

async def produce():
    print("Running produce()")
    
    #ring buffer
    dma_buffer = memoryview(bytearray(au_chunk_len*au_chunks))

    f=0
    while True:
        b = dma_buffer[f*au_chunk_len:(f+1)*au_chunk_len]
        t = au_chunk_len
        while t>0:
            t -= await sreader.readinto(b[au_chunk_len-t:])            
        await queue.put(b)
        f= (f+1)&(au_chunks-1)
        
            
app = web.App(host='0.0.0.0', port=80)

@app.route('/')
async def scan_network_handler(r, w):
    w.write(b'HTTP/1.0 200 OK\r\n')
    w.write(b'Content-Type: application/octet-stream\r\n')
    w.write(b'\r\n')

    # empty queue
    for i in range(au_chunks):
        _ = await queue.get()

    for i in range(30):
        print(f"c {i}, {queue.qsize()}")
        samples = await queue.get()
        w.write(samples)
    await w.drain()   


# Start event loop and create server task
loop = asyncio.get_event_loop()
loop.create_task(app.serve())
loop.create_task(produce())
loop.run_forever()

Start with the provided ESP32 I2S reproducer and compare its streaming behavior across the reported sample rates. Read the I2S and asyncio stream interfaces used by the example, then determine what evidence is needed to reproduce the failure. Done means the same streaming example works reliably at rates below and above 22050.