StopNotify not firing? (was: Query BLE connected status?)

[Travis Griggs <travisgriggs@gmail.com>]

> On Sep 12, 2016, at 8:52 AM, Travis Griggs <travisgriggs@gmail.com> =
wrote:
>=20
> It seems to me though, that maybe I=E2=80=99m going about this wrong. =
I don=E2=80=99t care about the device identity, or which devices are =
connected or not. What I really care about is if any device is connected =
to my app. And maybe I have this (kind of indirectly). My characteristic =
will get a StartNotify/StopNotify event on connect/disconnect edges. I =
can just use those to keep track of when I=E2=80=99m active or not.

So I implemented this, and now notice that while I get the StartNotify =
events, I don=E2=80=99t seem to get the StopNotify events.

In one case, I just shut down my iOS app (which had successfully =
triggered the StartNotify), while the device eventually showed up as =
disconnected, it never propagated a stop notify.

In the next case, I used the LightBlueLE app which allows one to =
explicitly start listen and stop listen. Explicit stop listen commands =
on either didn=E2=80=99t show anything.

Running btmon during a start listen/stop listen cycle produced the =
following output:

# btmon
Bluetooth monitor ver 5.41
=3D New Index: 5C:F3:70:68:C1:F9 (Primary,USB,hci0)               [hci0] =
0.149811
> ACL Data RX: Handle 64 flags 0x02 dlen 9                      [hci0] =
2.681703
      ATT: Write Request (0x12) len 4
        Handle: 0x000d
          Data: 0100
< ACL Data TX: Handle 64 flags 0x00 dlen 5                      [hci0] =
2.693201
      ATT: Write Response (0x13) len 0
> HCI Event: Number of Completed Packets (0x13) plen 5          [hci0] =
3.036696
        Num handles: 1
        Handle: 64
        Count: 1
> ACL Data RX: Handle 64 flags 0x02 dlen 9                     [hci0] =
11.862591
      ATT: Write Request (0x12) len 4
        Handle: 0x000d
          Data: 0000
< ACL Data TX: Handle 64 flags 0x00 dlen 5                     [hci0] =
11.864894
      ATT: Write Response (0x13) len 0
> HCI Event: Number of Completed Packets (0x13) plen 5         [hci0] =
12.161577
        Num handles: 1
        Handle: 64
        Count: 1


(also, having btmon running when connected caused btmon to buffer =
overflow and die)=