|Project ESP audio sensor|
|ESP-based audio sensor|
This project is about using an ESP-32 together with an I2S digital microphone to create an audio sensor.
This could be a decibel meter, or perhaps an environmental noise meter.
Audio levels are generally measured in dB using the A-weighted scale. A-weighting calculates a subjective loudness level from a physical loudness.
Energy it calculated per octave and an A-weight factor is applied. In decibels this means adding a octave-specific number to the loudness.
The physical device consists of:
- an ESP32 (or possibly an ESP8266), it has an I2S digital audio input.
- a digital I2S microphone, like the INMP441 (datasheet)
The microphone is connected as follows:
- INMP441 GND to ESP32 GND
- INMP441 VDD to ESP32 3.3V
- INMP441 SD to ESP32 A4/32
- INMP441 SCK to ESP32 A16/14
- INMP441 WS to ESP32 15
- INMP441 L/R to ESP32 GND
Initial code can be found on github.