Android BLE 4.3 onDescriptorWrite returns status 128 on enabling characteristics notification

Question

A question on enabling characteristics using the new android BLE 4.3:

I am not getting any notification from the BLE device though I enable notification on characteristics one by one asynchronously using a queue.

I also write the descriptor with UUID "00002902-0000-1000-8000-00805f9b34fb" with ENABLE_NOTIFICATION_VALUE.

I have followed the recommendation from Google sdk doc and as well suggestions from various forums.

By the way I get status = 128 on "onDescriptorWrite". Any idea as what this status means?

I went thru google code and did not see any info on this. Even the source code does not throw any light as how this status is being set.

Let me know if any of you have experienced this when you enabled notifications for the body media device. Also at times I get status 133 on descriptor write. I use latest Nexus 7 for my tests.

Answer 1

I had the same problem, and solved it by disabling and reenabling the bluetooth interface.

The Android BLE stack seems to be still immature and suffers from instability problems.

Answer 2

This error could be related to max threshold imposed by Android OS.

#define BTA_GATTC_NOTIF_REG_MAX     15

 - for 4.3 max number of notification/indication is 4 
 - for 4.4 max number of notification/indication is 7
 - for 5.0 max number of notification/indication is 15

https://groups.google.com/forum/#!topic/android-platform/FNHO5KB4sKI

https://android.googlesource.com/platform/external/bluetooth/bluedroid/+/android-5.0.2_r1/bta/gatt/bta_gattc_int.h