#ESP32 I2S MEMS Microphone Arduino IDE Example This repository holds some samples for connecting a I2S MEMS microphone to an ESP32 board.

At first I thought hooking up an I2S microphone would be straight forward, but it seems that I2S is a somewhat new or neglected interface. The examples distributed by adafruit only apply for Feather M0; the generic I2S example from the ESP32 examples is not directly applicable. Hence this repository.

Components used in this example

I am using these components:

• adafruit-huzzah32-esp32-feather
• adafruit-i2s-mems-microphone-breakout

How to connect the components?

There are no dedicated I2S pins on the ESP32. Instead, you will have to configure/enable the pins in your code. Eventually, I connected I2S-MEMS pins to the following ESP32 pins:

• SEL is unconnected, i.e. only one channel, apparently left
• LRCL to #15
• DOUT to #32
• BCKL to #14
• GND to GND
• 3V to 3V

Don't try to connect them to the similar sounding SCL/SCA/SCK, they're for the incompatible I2C interface.

How to use the examples?

You can open each of the examples as a sketch in the Arduino IDE. I've commonly used a baudrate of 115200, you will need to configure this in your serial monitor, otherwise it'll display rubbish.

Noteworthy

• Either the SEL config is wrong, or the ESP32 I2S channel handling.
  • I had to use I2S_CHANNEL_FMT_ONLY_RIGHT whenever SEL pin was unconnected/ground, and I2S_CHANNEL_FMT_ONLY_RIGHT when SEL is high.
• I could only get it to work with 32 bit sampling.
  • I don't know if this is a limitation of either hardware, or a configuration mistake on my side.
• Although the setup seems to react nicely to noise.
  • I do not know if the recorded data is actually a valid sound.
  • There might be some bit-juggling still to be done.

Credits

Credits go to Adafruit for the easy-to-use hardware and the nice guide (even if it is not fully applicable here, it's still a great place for starters) and the espressif examples.