Introduction - If you have any usage issues, please Google them yourself
Communication between STM32 Chip and Bluetooth HC-05
Bluetooth: A wireless technology standard that enables short-range data exchange between fixed devices, mobile devices and building personal area networks (using UHF radio waves in ISM bands of 2.4-2.485 GHz). Bluetooth technology was originally created in 1994 by Ericsson, a telecommunications giant, as an alternative to RS232 data line. Bluetooth can connect multiple devices, and it has been widely used in connection with microcontrollers.