[doragasu]’s wife is always misplacing her keys. To solve this problem, [doragasu] created a small Bluetooth-enabled key fob that is able to remotely sound an alarm when commanded to by a cell phone.
The case and LiPo battery of [doragasu]’s project comes from a small photo frame key fob. The LCD display and PCB of the photo frame were tossed aside for a future project, and the design of the circuit started. The Bluetooth buzzer key fob is based around an MSP430 microcontroller because of their extremely low power requirements.
On the software side of things, [doragasu] built a J2ME app to connect to the key fob and turn the buzzer on. His app is portable to any Android phone, and versions can be ported to Windows, OS X and iOS devices.
How does it work? Well, [doragasu]’s wife sometimes forgets to charge her key fob, rendering the whole project useless. There are ideas for updating the device to a Bluetooth 4.0 Low Energy device, but no actionable plans. Still, very good work. You can check out [doragasu]’s walkthrough and demo video after the break.