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… ...

It all starts with the HC-05 Bluetooth module, which is meant to transfer serial data, but which can be converted into a general-purpose device costing ten times as much with a simple Flash ROM ...

Fortunately, Bluetooth modules like the HC-05 and HC-06 can send serial signals wirelessly from your Android device straight to your microcontroller. Once paired, these modules relay serial ...