I built the ble_app_proximity project and down load into my board, it can advertise and can connected by the lightblue and the nRF toolbox, But i sent the hex value of 0x02 via alert Level characteristic, it can't callback the "ble_bas_on_ble_evt", also i used the nRF toolbox App and clicked "FindMe", it also can't callback the "ble_bas_on_ble_evt". and the nRF toolbox App can't get battry infomation of the device. Also I can't enabe the notification of the battery level characteristic. I used the SDK version 10, it also can't work. I use iar to build the project. What can I do next to solve this problem.