ESP WiFi Spy Microphone (ESP32 and ESP8266)

I recently have updated “ESP WiFi Microphone” project to rev 1.3 and now the revision 1.4 is available which is stronger and more stable than rev 1.3.

This project is compatible with both of ESP8266 and ESP32 modules and you can simply upload it on NodeMCU, ESP32 DEVKIT and other similar boards.

In the latest revision I have increased the audio bit-rate of ESP32 up to 192Kbps and ESP8266 up to 110Kbps.

ESP32 works in 16KHz sample rate with 12 bit resolution and ESP8266 works in 11KHz/10bit.

Also there was a bug in secure link and I have fixed this bug too.

Here are the links for “ESP WiFi Microphone” project:

ESP8266/NodeMCU WiFi Voice Recorder Arduino Source Code – Rev 2

ESP32 WiFi Voice Recorder Arduino Source Code and Schematic – rev 2.0

The WebApp is available at 192.168.4.1 or the router’s DHCP address. Either you can connect directly to the module’s hotspot SSID or connect to the modem in case your module is connected to the modem.

Also you can either use the “WaveShare Sound Sensor” or the suggested circuit (which is based on LM386, capacitors, resistors and a “Electret Microphone”) in the manual file, as the audio input circuit.

You can check to audio signal in the Oscilloscope page of the WebApp.

The best shape of audio signal is a horizontal line when its silent and tip of the waves must be sharp or circular when there’s some voices or noises in the environment. You can set the best signal shape with turning the potentiometer of the audio input circuit.