Nordic_UART auto-disconnection issue on Android L

[Alex Zhang]

Hi Nordic Expert,

I am Alex and have been developing with NRF51822 for a long time. Thanks for your quick help before. Now our product bases on S110-7.1.0 and SDK-6.1.0, and we reuse the demo Noridc UART profile inside our first BLE product. In other side, we also use many tools from you to do testing and verifying, such as MCP, NRF toolbox and NRF UART.

Now I met a very srange issue about that UART profile. Before this, the UART profile worked fine on Andrioid 4.4 (KitKat) platform. But recently we move to use Android 5.0 (L), we found an issue that once we do a connection with that profile, in a very short time it seems our BLE device is auto disconnected, and then this procedure repeats again and again when using NRF toolbox UART(ver 1.16.1). See attached figures.

Later I tried with NRF UART (V2.0) and surprised that this tool can build very stable connection with my device. And then I try MCP tool. Yip, it also can find the device, if I directly click 'connect' button, all is the same as NRF UART. But if I choose to click 'connect with autoConnect', the same issue is duplicated as NRF toolbox. I am so confused with this phenomenon. Any tips? I attached some screenshots for your reference.

Look forward to seeing your answer and help. Thanks a lot.

Alex

[Alex Zhang]

Hi, yes, i can share the hex, but i am not sure it can be run at DK since our product has its own pin assignment. Actually, we totally copy your UART example code so it should be the same but different from GPIO pins. Hm...it doesn't mean in each android 5.0 device, I can duplicate this issue, some of them can work too. Now I use Xiaomi Note 2 (Android 5.0.2), it's pity that I never connect my device on this phone using NRF Toolbox(V1.16.1):-(. BTW, we don't wann change SDK bcz we have done many testings for current SDK and SD. What can I do to help you analyse further? Please let me know. I will try my best. Thanks in advance.