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… ...

Arduino Bluetooth Control by Broxcode: This app offers some interesting functionality, but the full-screen ads make it extremely difficult to use. Arduino Bluetooth RC Car by Andi.Co: Specifically ...

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 ...