You need prepare:
SH-HC-08 1pcs
Serial Module 1pcs
APP
SerialPort software
Connection
SH-HC-08 Bluetooth Module CP2102 (set to 5V)
RXD TXD
TXD RXD
GND GND
VCC 5V
Download APP:
IOS is HM10 bluetooth serial lite, you can search it in APP Store
Android is DSD TECH Bluetooth, you can search it in Google Play
Open APP in your phone, open serial port software in your computer, then you can send and receive message between your phone and computer
For example, you enter message on your phone: hi, then you will see hi in the SerialPort software