S132 Attribute Table Size

[oneguy]

Hi,

referring to the SoftDevice Specification, S132 Softdevice vx.0, paragraph 15.2 (Attribute table size) I wonder how one does work out the size of the attribute table.

The reference given at the bottom of the paragraph refers to the API and the API refers back to the S132 SoftDevice specification.

As I have quite a number of attributes I'd like to make sure my attribute table has got the right size.

Thanks four your help Matthias

[bjorn-spockeli]

Hi Matthias,

I am afraid that there is no way to calculate the attribute size for a given number of services and characteristics( the internal build-up of the attribute table is "hidden" in the SoftDevice, which is not public information).

You will get the NRF_ERROR_NO_MEM error when you add services and characteristics with sd_ble_gatts_service_add and sd_ble_gatts_characteristic_add and the attribute table size is to small. Thus, finding the correct attribute is a process of trail and error, i.e. increase the attribute table size until you dont get any errors.

-Bjørn

[oneguy]

Hi Bjørn,

Thank you - that's how I have done it.

Please confirm: Once I have finished calling sd_ble_gatts_service_add and sd_ble_gatts_characteristic_add the attribute table has grown to its final size and will never expand again?

Regards Matthias

[bjorn-spockeli]

Yes, you are correct. The attribute table will not increase in size after you have added all your services and characteristics.

[oneguy]

Thanks :-)

[bjorn-spockeli]

Happy to help ;) I would appreciate if you could mark the answer as correct(click the check mark in the circle tot he left of the answer).