Error 8 (0x8) GATT CONN TIMEOUT On Android

[why_do_i_need_a_user_name]

NRF51422 Custom board

SD310 v3.0

Phone: LG K8 4G

Android 6.0

SDK 9.0.0 Boot-loader example

I am testing over the air DFU with our custom device.

a.) DFU using NRF Toolbox on IPhone works fine.

b.) DFU using MCP\NRF51 dongle works fine.

c.) DFU using NRF Toolbox on Android fails with "upload failed GATT error"

nRFConnect on Android can connect with our device but loses the connection after about 6 seconds and the logger captures the following error:

Error 8 (0x8) GATT CONN TIMEOUT

[why_do_i_need_a_user_name]

Could you clarify this: nRFConnect on Android can connect with our device but loses the connection after about 6 seconds

We are testing our bootloader with Android.

When I got the Android error message I thought if I used nRFConnect/nRFLogger I could collect detailed logs to help you diagnose the problem. The failed DFU is the problem we wish to resolve.

Was your device running bootloader firmware or your application ? Our device is running the dual bank bootloader example (with tiny modifications)

Did you start doing DFU before you get the GATT CONN TIMEOUT ? Yes, we select our device, start the UPLOAD, the upload begins then we get GATT CONN TIMEOUT

Have you tried to test with other Android phone ? Our customers have had success with other Android phones. I do not have access to other phone models at the moment.

I will make the changes to the bootloader that you have suggested and report back.