ANNEX32 I2S-pinout

[PeterN]

The MAX98357A integrates an I2S digital-to-analog converter and a 3-Watt-class-D audio amplifier on a very small board. 

It is a perfect monaural (L+R) "sound card" for an ESP32, but can also be configured as a DAC/amplifier for the left or right channel. The power supply is 5V or 3V3

It was easily connected to an ESP32 with ANNEX32  that works now as an Internetradio. 

But I found a different connection scheme than in the help file.   The LRC- and BCLK- pins at  the ESP32 appear to be reversed - assuming that the print on the board an in the documentation is right. 

This works:

MAX98357A_LRC <--> ESP32  GPIO26   (but helpfile says IO05 is LRCK)

MAX98357A _BCLK <--> ESP32 GPIO05  (but helpfile says GPIO26 is BCLK)

MAX98357A _Din <--> ESP32 GPIO02   (OK)

MAX98357A _SD <--> Vin

MAX98357A _Gain <--> Vss/ground

So there might be an error in the ESP32 help file.

Since I do not have any of the I2S DACs from the help file for testing: Can anyone verify or confirm this?

https://learn.adafruit.com/adafruit-max98357-i2s-class-d-mono-amp/downloads

[PeterN]

Hi cicciocb

The pinout  in the section for the  I2S-interfacein of the ANNEX32 help file   indeed needs the upper described correction. 

The right I2S-pinout of pins 5,2,26 already is in the section "WIRING" and corresponds with my I2S-DAC boards:

[cicciocb]

Hi Peter,

I had the time to check and I confirm that there is an error in the schematics but the table is correct.

I fixed in the doc for the next release

Thanks