Hello, I am still learning about BLE devices and have a quick question regarding the Generic Access Profile. I understand that GAP defines 2 things:
- The discoverability of a device
- Things like scanning and advertising.
- The connection of a device.
- How the device connects to another device, as well as how that connection is managed afterward.
With that in mind, I am currently using my nRF52-DK to follow the connection between a fitness device and my smartphone. I am also using the Packet Logger on my phone as a reference to the packets that are being transmitted between the two devices for comparison's sake.
My question is in regards to the following log file I generated in which almost every packet was appended with "Generic Access Profile: Unknown":
411 11.078 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Write Command, Handle: 0x001a (Generic Access Profile: Unknown) 412 11.081 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Write Command, Handle: 0x001a (Generic Access Profile: Unknown) 413 11.083 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Write Command, Handle: 0x001a (Generic Access Profile: Unknown) 415 11.172 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown) 417 11.326 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Write Command, Handle: 0x001a (Generic Access Profile: Unknown) 418 11.415 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown) 419 11.417 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown) 421 11.708 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown) 422 11.709 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown) 423 11.713 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Write Command, Handle: 0x001a (Generic Access Profile: Unknown) 424 11.717 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Write Command, Handle: 0x001a (Generic Access Profile: Unknown) 426 11.825 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Write Command, Handle: 0x001a (Generic Access Profile: Unknown) 427 11.903 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown) 428 11.904 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown) 430 12.326 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Write Command, Handle: 0x001a (Generic Access Profile: Unknown) 431 12.392 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown) 432 12.392 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown) 434 12.684 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown) 435 12.687 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Write Command, Handle: 0x001a (Generic Access Profile: Unknown) 436 12.824 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Write Command, Handle: 0x001a (Generic Access Profile: Unknown) 438 12.878 db:3c:95:e1:8a:e8 () ATT Rcvd Handle Value Notification, Handle: 0x0017 (Generic Access Profile: Unknown)
Could someone explain to me what exactly this means? By looking at the Attribute List, it seems that the only Attributes in the Attribute Table are the Generic Attribute Profile (0x1801) and the Generic Access Profile (0x1800):
326 8.003 db:3c:95:e1:8a:e8 () ATT Rcvd Read By Group Type Request, GATT Primary Service Declaration, Handles: 0x0001..0xffff 327 8.005 SamsungE_06:de:4a (Galaxy S8+) ATT Sent Read By Group Type Response, Attribute List Length: 2, Generic Attribute Profile, Generic Access Profile
But given that this is a Fitness Device communicating with a Smartphone, I would expect more data or attributes to be shared between them like Battery Level or even manufacturer specific UUIDs that cover other services.
