I2S details

[mfantin]

I'm planning to use ESP32 in an application to connect a BT hearphone and interface a processor via I2S. There is a detailed specification about the use (hw and fw) of I2S?
Thank you

[ESP_Sprite]

At the moment, not yet. The I2S module in the ESP31 is much like that in the ESP8266, so yo can use those docs plus the SMS emulator in the Github repo if you want to use that. The I2S module in the ESP32 is a lot more advanced, but there are no documents for that yet, unfortunately.

[nicolas]

Now that ESP32 is out, maybe you could tell us more now. Some new I2S functionnalities are mentionned in the datasheet (like BT PCM), but besides audio applications, I was wondering about I2S ports max "bit-bang" capabilities as very-high-speed serial inputs/outputs ...
For it's "TV-broadcast" experiment on an (overclocked) ESP8266, Cnlohr did use the i2s port at its full 80 MHz speed. Will this still be possible with ESP32 ?

In section 32.2.4 of Technical Reference Manual, Table 11 shows that I2S can rely on APPL_CLK (up to 128 MHz) or PLL_D2_CLK (160 MHz). Can you confirm I2S can be programmed to fetch data at these speeds using DMA (and even with the 2 ports simultaneously, if bus and memory can sustain it) ?

[davydnorris]

One of the least documented interfaces on the ESP8266 is the I2S, so I am really hoping that this will improve the documentation of both chips!

It was only through the work of a few community members that I found out how to do I2S input using DMA buffers - this section of the documentation is sorely lacking!! It would be great if both chips got improved information for this spec as it's essential for all digital audio applications.

I also want to use I2S with a 100BaseT hard wired ethernet connection to do AoIP applications with this chip. Even better would be some way of adding a hardwire ethernet port and using the existing TCP/IP stack directly!

[mgleason_3]

+1 for documentation and examples for _ i2s _

Please BOTH directions (input AND output) so we can use external DACs, etc!

[ESP_Sprite]

Fyi, we have someone working on an I2S driver - it should appear in esp-idf soon-ish. The documentation for the I2S driver is going to take a bit longer, but I've tried to boost its priority a bit due to a lot of people wanting to use this interface - it should also appear in the technical reference manual once it's done.

[uflorin]

Please find here my implementation of the I2S driver for ESP32 tested with MAX98357A PCM amplifier: https://github.com/pewit-tech/esp32-i2s .