Maximum number of services

RE: Maximum number of services

andy2003hunan — Mon, 16 Sep 2013 06:00:43 GMT

ok,thank you anyway.

RE: Maximum number of services

Carles — Mon, 16 Sep 2013 05:49:07 GMT

I doubt it, but I am not sure. For iOS related questions there may be better forums than this one however.

RE: Maximum number of services

andy2003hunan — Mon, 16 Sep 2013 05:42:00 GMT

ok,thank you. and does IOS has the limitation of the number of services and characteristics?

RE: Maximum number of services

Carles — Mon, 16 Sep 2013 05:33:16 GMT

by the way,is the characteristics number in a service limited?if is,what is the maxim number?

No, not at all. There are no limits at all imposed by the stack in terms of service, characteristic or descriptor counts. The only limit is the memory available for the attribute table.

Carles

RE: Maximum number of services

andy2003hunan — Sat, 14 Sep 2013 05:03:50 GMT

by the way,is the characteristics number in a service limited?if is,what is the maxim number? tks!

RE: Maximum number of services

Artem Zemlyanukhin — Fri, 13 Sep 2013 06:00:59 GMT

Ok, thanks!

RE: Maximum number of services

Carles — Fri, 13 Sep 2013 05:59:10 GMT

No, CCCDs as of today have to live inside the stack. The reason for that is that it is the stack itself the one that actually creates them.

RE: Maximum number of services

Artem Zemlyanukhin — Thu, 12 Sep 2013 17:48:23 GMT

Thank you, I optimized my services and they all fit.

And I am interested, can I store CCCD data in user ram? CCCD also has 'vloc ' parameter, but donn't see where I can pont data.. There is no corresponding struct member for pointer to cccd data.

RE: Maximum number of services

Ole Morten — Tue, 10 Sep 2013 12:30:36 GMT

Also see this answer to another question: https://devzone.nordicsemi.com/index.php/sd-characteristics-per-service-limit#reply-827

RE: Maximum number of services

Carles — Tue, 10 Sep 2013 11:40:43 GMT

Hi there,

Could you tell me please the maximum supporting number of services?

There really is not a maximum number of services in the attribute table. Instead, the table is allocated a fixed number of bytes in memory and you fill those in when you add attributes in general, until space runs out and no more can be added.

This number may be varied depending on number of attributes in each service and its size. So how can I evaluate maximum size of GATT table?

Unfortunately at this point you cannot with exactitude. You will have to try and fit what you need until you run out of memory. We have not made the layout of our internal table public, and so I cannot give you exact numbers.

Also I interested in what cases it is advantageous to use option BLE_GATTS_VLOC_USER. For example, I have attribute with length 1 byte. If I use BLE_GATTS_VLOC_USER, I think, stack will have pointer to my data (size of pointer = 4 bytes). If I use BLE_GATTS_VLOC_STACK, does is take 1 byte in table inside Stack?

The internal pointer exists regardless of the vloc type you use. Hence the more attributes with BLE_GATTS_VLOC_USER the less space you will take inside our attribute table and the more services/characteristics/descriptors you will be able to fit.

Regards,

Carles