The ESP32 comes with Wi-Fi, Bluetooth Low Energy and Bluetooth Classic. In this tutorial, you’ll learn how to use ESP32 Bluetooth Classic with PlatformIO to exchange data between an ESP32 and an Android smartphone.
At the moment, using Bluetooth Classic is much more simpler than Bluetooth Low Energy. If you’ve already programmed an Arduino with a Bluetooth module like the HC-06, this is very similar. It uses the standard serial protocol and functions.