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 ...

It’s hard to imagine an easier way to set up communications between an Android device and an Arduino using Bluetooth ... see the cheap and ubiquitous HC-05 Bluetooth module.

Fortunately, Bluetooth modules like the HC-05 and HC-06 can send serial signals wirelessly from your Android device ... but the full-screen ads make it extremely difficult to use. Arduino Bluetooth RC ...