Rcvd Error Response - Attribute Not Found, Handle: 0x0008

[Paul]

I am troubling shooting some issues between my device and iPhone using nRF Sniffer.

One of the errors the sniffer captures is this:

Master to Slave: Rcvd Read By Type Request, GATT Characteristic Declaration, Handles: 0x0008..0x0008

Slave To Master: Rcvd Error Response - Attribute Not Found, Handle: 0x0008

In previous response, Handle 0x0008 is for UUID 0x1801 (Generic Attribute Profile)

There is a ble_gap_conn_params_t for setting up Generic Access Profile (GAP), I am just wondering is there something for setting up Generic Attribute Profile?

It seems to me that I missed something that the central is expecting for Generic Attribute Profile.

[Paul]

I am running the ble_app_hrs_rtx with iPhone nRF Toolbox to compare. It has the same error. What is iPhone looking for for 0x1801?

[Anders Strand]

According to the bluetooth docs, it seems to be the Service changed characteristic. It is optional to include this characteristic. It is used to indicate to a central that the device has a new GATT table, and that the central should do another service discovery.

During service discovery, a central might try to find many things (after all, it is in the process of discovering what is there). It is no cause for alarm when it does not find everything is looks for.

[Paul]

Yep. I set the service change flag to 1 and that error is gone. Thanks

[Paul]

I did further comparison: the off the shelf product has properties: Read, Indicate. (0x22).

nRF51422 has only Indicate. (0x20)

The UUID is correct: 0x2A05

I don't see softdevice has provided any configuration for 0x2A05.

[Paul]

OK, I see the answer on the page your linked: only indicator is mandatory. All others are excluded. What does "excluded" mean technically?