Hello.
I use SDK 8.0.0 and PCA10028 board. I try connect board to the Windows 8.1 PC ( i have Tablet PC and Desktop PC with BLE dongle). For connect board to Windows i must perform pairing procedure in PC Settings. After that board available for communications.
I tried to pairing different applications - HRS, HTS and uart_to_ble, and same from SDK_7.2.0 (experimental_ble_app_uart). Only uart_to_ble application from last SDK do not pairing to Windows.
SDK 7.2 pairing procedure (experimental_ble_app_uart) log:
SDK 8.0 pairing procedure (ble_app_uart) log:
Please, check this Issue, may be problem on Windows side.