Increase number of Characteristics

[Moe]

I am using the ble_blinky example (s132) and want to increase the number of characteristics. I get the error code 4. I think the storage capacity is not the reason why I can't create more characteristics. In the a try I implemented some variables to see if I can still create the same number of characteristics, and yes I can. I read in some old Posts about a limitation for the GATT Table or the number of characters per service but I couldn't find these parameters anymore.

I tried with the the is_value_user parameter as well. Maybe I haven't used it right but the number of characteristics didn't increase and reacted the same way like before.

I hope somebody has an idea

[Marjeris Romero]

Hi Moe,

As Steve suggested, you may need to increase NRF_SDH_BLE_VS_UUID_COUNT. In addition to this you may also need to increase the RAM size allocated for the Softdevice. If you enable the NRF_LOG module you will get a message if this is necessary. To enabled NRF_LOG go to sdk_config.h and search for "NRF_LOG_ENABLED"

// <e> NRF_LOG_ENABLED - nrf_log - Logger
//==========================================================
#ifndef NRF_LOG_ENABLED
#define NRF_LOG_ENABLED 1
#endif

Best Regards,

Marjeris

[Moe]

Hey msromero,

thank you for the fast response. With the "NRF_LOG_ENABLED" it told me to change the RAM size. The Log Output is: " <error> app: Fatal error" and the error code is still 4. Increasing the NRF_SDH_BLE_VS_UUID_COUNT didn't worked either. The error Codes are still the same and I can't get more Characteristics.

[Marjeris Romero]

Hi Moe,

Did you change the RAM size and that didn't work either? Could you get me a printscreen of the debug terminal?

-Marjeris

[Moe]

Hi Marjeris,

This is what happens if I just upload the Code.

The Picture below shows the Log if I I am in the Debugger

If I start the Debugger it stops at the NRF_BREAKPOINT_CMD. Before the Breakpoint the funktion "characteristic_add" returns the error code 4

[Marjeris Romero]

Hi,

Did you increase the RAM size?

If you set the NRF_LOG flag to debug you will print the debug messages and that will make your code easier to debug. Just search in the sdk_config.h for NRF_LOG_DEFAULT_LEVEL and change the level flag from 3 (Info) to 4 (debug).

// <o> NRF_LOG_DEFAULT_LEVEL  - Default Severity level
 
// <0=> Off 
// <1=> Error 
// <2=> Warning 
// <3=> Info 
// <4=> Debug 

#ifndef NRF_LOG_DEFAULT_LEVEL
#define NRF_LOG_DEFAULT_LEVEL 4
#endif

Best Regards,

Marjeris

[Moe]

Hey Marjeris,

The first time it told me to change the Adress and Size to 0x200022B0 and 0xDD50 which I did. The NRF_LOG_DEFAULT_LEVEL change (to 4) didn't printed any new information. Due to this I added in the creation of the characters a NRF_LOG_INFO to print the error code (thats the <info> app: XY ), that I don't have to debug everything step by step and still can see if something changed. 

[Marjeris Romero]

Hi Moe,

Sorry, I forgot to mention you also need to increase NRF_SDH_BLE_GATTS_ATTB_TAB_SIZE if you have a large number of characteristic in your custom service.

If you are expecting debug information from a particular module you also need to enable NRF_LOG and change the default log level to 4 for the specific module.

Maybe you can upload your project here so I can take a look at the code inside if increasing the attribute table size does not work.

Best Regards,

Marjeris