I gor NRF_ERROR_FORBIDDEN return value when I called "sd_ble_gatts_characteristic_add" to add a new charateristic.

[AlanBle]

NRF_ERROR_FORBIDDEN

Forbidden value supplied, certain UUIDs are reserved for the stack.

I was developing a new sw in demo board. I have added some new services  and charateristics inmy project, and I tested it ,it was ok. I can find these services and charateristics . 

however when i was adding a new charateristic with a UUID 0x0030 ,I gor NRF_ERROR_FORBIDDEN return value when I called "sd_ble_gatts_characteristic_add" to add a new charateristic. (code is shown on  below pictures )

my questions : which UUIDS are reserved for the stack( S130  SwDevice ). where can i get a table of reserved UUID. so taht I can know which UUIDs i can use .

[AlanBle]

hello ,

I found that it is beacause add too many charateristics and services . (I had added about 40 charateristics and 6 services )

so my new question is:  how many chars and services can I add to S120 stack ? 

[Einar Thorsrud]

Hi,

There is no maximum number of characteristics. But you may need to allocate more memory to the attribute table by setting a higher value for NRF_SDH_BLE_GATTS_ATTR_TAB_SIZE in sdk_config.h.

[AlanBle]

sorry , I counld not find NRF_SDH_BLE_GATTS_ATTR_TAB_SIZE in sdk_config.h. 

i am using nrf5_SDK_12.2.0_f012efa .  chip is NRF51822 . 

[Einar Thorsrud]

Hi,

I see. For the older SDKs you need to adjust the parameters in the ble_enable_params_t instance you pass to softdevice_enable. Among other things that contain gatts_enable_params (ble_gatts_enable_params_t) which holds the attr_tab_size.

[AlanBle]

hello I have adjusted    ble_enable_params.gatts_enable_params.attr_tab_size to  0x800 even bigger , but problem still exist.

[AlanBle]

and I found that if set this var(attr_tab_size) more than 0 , chip will die.

 

[AlanBle]

this is the default value on my project .

[Einar Thorsrud]

AlanBle said:

and I found that if set this var(attr_tab_size) more than 0 , chip will die.

When you write dies, what does that mean? Did you debug, and what did you find?

If I am to guess, perhaps adjusting the atribute table sizea increases the SoftDevice RAM usage so that it overlaps wiith the application's RAM region. To fix this, you can adjust the application RAM start address, and reduce the size correspondingly. This values does not need to be exact, so that it is OK to give the SoftDevice a lot of head-room as long as you still have enough RAM for your application.