The HC-05, a Bluetooth to serial bridge, can be found for around $5 on the internet and therefore may be the cheapest way to add Bluetooth connectivity to your project. However, its default setting… ...

An HC-05 Bluetooth module is connected to an Attiny85, with some transistors to control a 5V power output. The Arduino takes care of a bluetooth connection and uses a serial input to control the ...

This research work presents a novel approach to interact with a Bluetooth speaker through hand gestures, employing an Arduino Uno microcontroller, APDS-9960 gesture sensor, HC-05 Bluetooth module, and ...