Hello,
I use the nrf51 with SDK 12.3.0.
I followed the tutorial for custom services and added characteristics as described here: https://devzone.nordicsemi.com/tutorials/b/bluetooth-low-energy/posts/ble-characteristics-a-beginners-tutorial
Now, if I compile the finished example application from the tutorial an execute it on the nrf51822 I can connect to the device using nrf connect.
Reading/writing the characteristic value works fine. However trying to read the value of the corresponding CCCD field (by tapping the small arrow beside it) will cause a timeout and a disconnect. The log looks like this:
nRF Connect, 2018-03-23 OurCharacteristic (E4:E6:7D:57:1C:6E) V 17:45:12.297 Connecting to E4:E6:7D:57:1C:6E... D 17:45:12.297 gatt = device.connectGatt(autoConnect = false, TRANSPORT_LE) D 17:45:15.795 [Broadcast] Action received: android.bluetooth.device.action.ACL_CONNECTED D 17:45:15.798 [Callback] Connection state changed with status: 0 and new state: CONNECTED (2) I 17:45:15.798 Connected to E4:E6:7D:57:1C:6E V 17:45:15.815 Discovering services... D 17:45:15.815 gatt.discoverServices() D 17:45:16.308 [Callback] Services discovered with status: 0 I 17:45:16.312 Services discovered V 17:45:16.332 Generic Access (0x1800) - Device Name [R W] (0x2A00) - Appearance [R] (0x2A01) - Peripheral Preferred Connection Parameters [R] (0x2A04) Generic Attribute (0x1801) - Service Changed [I] (0x2A05) Client Characteristic Configuration (0x2902) Unknown Service (0000f00d-1212-efde-1523-785fef13d123) - Unknown Characteristic [N R W] (0000beef-1212-efde-1523-785fef13d123) Client Characteristic Configuration (0x2902) V 17:45:22.100 Reading descriptor 00002902-0000-1000-8000-00805f9b34fb D 17:45:22.100 gatt.readDescriptor(00002902-0000-1000-8000-00805f9b34fb) E 17:45:52.113 Error 133 (0x85): GATT ERROR D 17:45:52.114 [Callback] Connection state changed with status: 0 and new state: DISCONNECTED (0) I 17:45:52.114 Disconnected D 17:45:52.254 [Broadcast] Action received: android.bluetooth.device.action.ACL_DISCONNECTED
If I write to the CCCD first (tapping the 3 arrows of the characteristic) then reading afterwards works fine.
I also checked the HRS example app and there this behaviour does not occur. Reading the CCCD works perfectly there, but I couldn't find a difference in the setup of the characteristic compared to the tutorial above.
The problem for me is that my central application (written in Qt) times out during service discovery because of this behaviour.
Has someone encountered this problem before and has a solution?
