nRF52833.Is BLE_GATTS_VAR_ATTR_LEN_MAX limited 512?

[hjk1994]

Hi,
    l’m have a new question:
   Is BLE_GATTS_VAR_ATTR_LEN_MAX limited 512?I need to adjust it in my project. I tried to modify the parameter of BLE_GATTS_VAR_ATTR_LEN_MAX , Increased to 1024.but it also return error.The error is caused by this API(sd_ble_gatts_characteristic_add).

   Kind regards!

[Sigurd]

hjk1994 said:

Is BLE_GATTS_VAR_ATTR_LEN_MAX limited 512?

Yes.

This is defined by the Bluetooth specification. From BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 3, Part F page 1485:

"The maximum length of an attribute value shall be 512 octets."

[hjk1994]

Thanks.

    The size of BLE HID report_map_data[] larger than 512 in my project ,which leads to the following error.What can i do? Can i add two HID service in project ?How to do?

Kind regards!

[Sigurd]

hjk1994 said:

Can i add two HID service in project

Yes, that is the way to do it if your report map is larger than 512 bytes.

See this snippet from the HID over GATT Profile Specification:

[hjk1994]

thanks!