Review on DIYmall ESP32 PICO KIT Development Board ESP 32 by Bilal Cartwright

This is awesome! Within an hour of connecting, I was having a full phone conversation. Connecting is very easy, just use a serial to USB converter. If I remember correctly the baud rate was 9600 but don't quote me. The microphone and speaker were very basic. It uses a regular elecret microphone (very small and cheap) and a regular speaker. *DO NOT* use this device with any of the Elecret devices that have an integrated circuit board, you literally need the + and - terminals on the tiny microphone. If you're not using a real speaker you can use a speaker to connect to the + and - pins, otherwise just use an amplifier/transistor circuit.