nRF51822 connection issue

[David]

Hi support team, We met an issue for connecting our device built in nRF51822 to Android device.

The nRF51822 uses below firmware program:

• nRF5_SDK_12.3.0_d7731ad
• s130_nrf51_2.0.1_softdevice The service we use is UART.

For using nRF Connect app. sometimes this app connects to device but gets unknown UUID service, and few seconds later, the app fixes the connection error and return to OK state.

For nRF Toolbox app, it will appear the error message "The device does not have required services." and never can get connection with the nRF 51822. Below is the screen shot: files.slack.com/.../screenshot_2017-06-14-10-44-24_1024.jpg

We have tested several mobile phones and some of them have this issue, the Sony, Samsung, Huawei and HTC is OK, but the Asus and Xiaomi has this issue. The Android OS version we tested is from version 4 to 7. It looks this issue has something to do with the phone manufacture, not the Android OS version.

This annoy us and our customer, it there any way we miss that can correct the error? Is there information you want that can confirm the cause of this issue?

Best Regards, David Huang

[endnode]

Hi David, have you considered to sniff what is really happening on the radio to see differences between the phones and getting the glimpse of what is going on? Does the behavior change when you erase network settings/BT Snare process in android or when you reset whole device to factory settings? Many issues with mobiles comes simply from different caching/lean update of parameters because there is low level BT stack managed typically by chipset provider (e.g. Broadcom) which is responsible for certain parts (e.g. GATT Service Discovery procedure, BT LE Security Manager layer implementation etc.) and then upper parts with "driver" and Android itself. These layers interact but it can have many different approaches and the same way you have millions bugs in upper parts of Android and its customs you will see them in BT interface as well.