Bluetooth Low Battery Over the Air (OAD)
Ti cc2541
Android 4.3.+ ~ 5.0.+
1. close all notification characteristics
2. enable oad characteristic notification
3. get device image version
4. check new image version
5. start update firmware...
6. if failed... slow send_interval time...
Ti official android app sample code download : https://git.ti.com/sensortag-android
