I have a bogus BLE device which exposes "badly" a characteristic notification. Even though it doesn't find a characteristic descriptor, I'm still able to start notifications and even receive value changed events. For info, Android and macOS raise an exception when trying to start notifications. See https://github.com/WebBluetoothCG/ble-test-peripheral-android/issues/63 See logs: < ACL Data TX: Handle 32 flags 0x00 dlen 9 [hci0] 403.621325 ATT: Find Information Request (0x04) len 4 Handle range: 0x002b-0xffff > HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 403.689256 Num handles: 1 Handle: 32 Count: 1 > ACL Data RX: Handle 32 flags 0x02 dlen 9 [hci0] 403.755926 ATT: Error Response (0x01) len 4 Find Information Request (0x04) Handle: 0x002b Error: Attribute Not Found (0x0a) --- [Nexus 5X]# list-attributes Primary Service /org/bluez/hci0/dev_46_EE_57_93_31_08/service0001 Generic Attribute Profile Characteristic /org/bluez/hci0/dev_46_EE_57_93_31_08/service0001/char0002 Service Changed Primary Service /org/bluez/hci0/dev_46_EE_57_93_31_08/service0028 Battery Service Characteristic /org/bluez/hci0/dev_46_EE_57_93_31_08/service0028/char0029 Battery Level [Nexus 5X]# select-attribute /org/bluez/hci0/dev_46_EE_57_93_31_08/service0028/char0029 [Nexus 5X:/service0028/char0029]# notify on [CHG] Attribute /org/bluez/hci0/dev_46_EE_57_93_31_08/service0028/char0029 Notifying: yes Notify started [CHG] Attribute /org/bluez/hci0/dev_46_EE_57_93_31_08/service0028/char0029 Value: 0x32 [Nexus 5X:/service0028/char0029]# notify off [CHG] Attribute /org/bluez/hci0/dev_46_EE_57_93_31_08/service0028/char0029 Notifying: no Notify stopped -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
