MicroPython Forum (Archive)

The sound should start pretty much right after the first write() method completes. The ibuf does not need to be full for sound to be heard. But, after the final write() method sound will continue until the ibuf is emptied of sample data. That delay can be calculated by the formula you listed.

I decided to order a Teensy 4.1. I'll keep the forum updated on progress.

alphaFred wrote: ↑

Tue Oct 26, 2021 5:48 pm

I hope that is fast enough for you

Definitely. These short code download times are similar to what I see with the RP2 port, which really helps to shorten the development time.

Thanks for all the dev board information. That helped a lot to understand development options. I took a look at the MIMXRT1020_EVK board schematic and BOM. This is a great development platform but it may not be the best choice for I2S development. I noticed that I2S capable pins are not brought out ...

Is there any timeline for I2S completion? I imagine that it will take a month or two. If that fits with your expectations I'll get started. Is the Teensy 4.1 the best hardware to develop with? Digikey/Canada has them in stock.

Roberthh wrote: ↑

Tue Oct 05, 2021 6:14 am

I2S and SP-DIF is on our list for new modules.

If someone is actively working on I2S for the Teensy I can offer to help them with the implementation. I did the I2S implementation for the Pyboards, ESP32, just recently the Pico. If no-one has started the work, I could take it on.

What a fun project ! Will the I2S software work on the Pico with just a PWM output? Unfortunately not. The I2S feature requires hardware that supports the I2S protocol. For producing sounds, you could use a product like the Adafruit I2S 3W breakout board . Pico firmware with the I2S feature is avail...

If you'd like to make an audio project with I2S there is a new PR and updated code in I2S examples repo to support the Pico. The firmware on your Pico board will need to be updated. There are a couple of options to get firmware: Integrate the I2S PR into your local build Use a firmware binary from t...

Your description is good. The async process is run by the MicroPython uasyncio scheduler. It polls the I2S instance to determine when space is available in the internal buffer (ibuf). The polling happens in 'yield core._io_queue.queue_write(self.s)'. When space is available, all, or portions, of the...

The top of each machine_i2s.c C file has some comments that might help to explain the implementation for each port. There is also a repo I authored with examples for the supported ports. https://github.com/miketeachman/micropython-i2s-examples If you can frame up some specific questions I can add an...