This is a sample project for receiving audio data using ESP32 microcontroller. The chip has a built-in 12-bit ADC which is used to process the analog audio from the external microphone module in real-time. The program also support input from I2S MEMS microphones that does not require the usage of the ADC. The received messages are optionally displayed on the attached OLED display.

Setup

NodeMCU-ESP32
OLED SSD1306
Microphone, tested with the following, but others could be also supported:
- Analog:
  - MAX9814
  - KY-037
  - KY-038
  - WS Sound sensor
- I2S MEMS:
  - SPH0645

Pinout

Analog Microphone

MCU	Mic
GND	GND
3.3V	VCC / VDD
GPIO 35	Out

Digital (I2S) Microphone

MCU	Mic
GND	GND
3.3V	VCC / VDD
GPIO 26	BCLK
GPIO 33	Data / DOUT
GPIO 25	LRCL

I2C Display (optional)

MCU	Display
GND	GND
3.3V	VCC / VDD
GPIO 21	SDA
GPIO 22	SCL

Demo

https://user-images.githubusercontent.com/1991296/177211906-2102e9fa-8203-4b80-82e6-4839bf66f01f.mp4

Watch high quality on Youtube