This project uses a Bean BLE dev board by Punch Through design and a smartphone to detect when a pair of sunglasses loses a BLE connection, indicating they have been left behind by the user. The location of the phone when the connection is lost is stored on the phone and an alert is generated for the user. The device will detect when it is at home by using the phones GPS location and will sleep until the accelerometer triggers an interrupt and wakes the device. The device will also detect pre-configured device IDs of third party bluetooth devices nearby such as a car handsfree device, to determine if the sunglasses are in the car, which will sleep the device until it moves again.
The final design would be integrated into the plastic arm of a pair of sunglasses, or attached later.