Discovering a VS UUID Characterisic, but it shows UUID as 0

Question

Hi, I am running SDK15, and using the example ble_app_interactive in ble_central and peripheral. I am trying to discover services and characteristic from a peripheral device, using NRF52 DK as a central device. There is a lot of services and VS services and characteristic in the peripheral. I can discover the services, and see the VS UUID services. As seen on picture: But when i try to discover the characteristics in the VS services, it writes out the UUID as 0. I have also made it print out it handles and it does have it's handles Both things is shown in pictures below. The UUID is 0. This is by using gatt characteristics

2EAF. If i then try to write gatt characteristics

AE62. I still don't get UUID, but my progam also crashes and gives me error code 11, but this is in the CCCD descriptor, as seen on picture: I have made extra logging. I have also increased NRF_SDH_BLE_VS_UUID_COUNT in sdk_config. I have also increased my maximum characterstics and services. Hope you can help. Regards Andreas

Dresse · Accepted Answer

And now it works like a charm! Thanks Hung! Fullscreen 20181123_121839putty.log Download =~=~=~=~=~=~=~=~=~=~=~= PuTTY log 2018.11.23 12:18:39 =~=~=~=~=~=~=~=~=~=~=~= uart_cli:~$ BLE app with command line interface example started. uart_cli:~$ Press Tab to view all available commands. uart_cli:~$ connect 0uart_cli:~$ uart_cli:~$ app: Scanning uart_cli:~$ Connected to address: uart_cli:~$ 08 uart_cli:~$ AE uart_cli:~$ D6 uart_cli:~$ 81 uart_cli:~$ 3F uart_cli:~$ 26 uart_cli:~$ uart_cli:~$ app: CENTRAL: Connected, handle: 0. uart_cli:~$ gatt services 08:AE:D6:81:3F:26 peer_manager_handler: Connection secured: role: Central, conn_handle: 0, procedure: Encryption uart_cli:~$ gatt services 08:AE:D6:81:3F:26 Current MTU: 247 uart_cli:~$ gatt services 08:AE:D6:81:3F:26 MTU changed successfully uart_cli:~$ gatt services 08:AE:D6:81:3F:26 app: Data length updated to 251 bytes. uart_cli:~$ gatt services 08:AE:D6:81:3F:26 peer_manager_handler: Connection secured: role: Central, conn_handle: 0, procedure: Encryption uart_cli:~$ gatt services 08:AE:D6:81:3F:26 Connection parameters update success uart_cli:~$ gatt services 08:AE:D6:81:3F:26 uart_cli:~$ app: GATT Services uart_cli:~$ app: Saving all Service DATA uart_cli:~$ app: Saving all Service DATA uart_cli:~$ app: Saving all Service DATA uart_cli:~$ app: Saving all Service DATA uart_cli:~$ app: Services count: 6 uart_cli:~$ Found service UUIDs: uart_cli:~$ UUID: 1801 type: 0x1 uart_cli:~$ UUID: 1800 type: 0x1 uart_cli:~$ UUID: AE62 type: 0x2 uart_cli:~$ UUID: 181C type: 0x1 uart_cli:~$ UUID: 180F type: 0x1 uart_cli:~$ UUID: 2EAF type: 0x3 uart_cli:~$ gatt characteristics 08:AE:D6:81:3F:26 AE62uart_cli:~$ app: Number of characteristics: 2 uart_cli:~$ Characteristics: uart_cli:~$ UUID: B52E type: 0x4 uart_cli:~$ With these parameters: uart_cli:~$ broadcast: 0 uart_cli:~$ read: 1 uart_cli:~$ write_wo_resp: 0 uart_cli:~$ write: 0 uart_cli:~$ notify: 1 uart_cli:~$ indicate: 0 uart_cli:~$ auth_signed_wr: 0 uart_cli:~$ UUID: AAA2 type: 0x5 uart_cli:~$ With these parameters: uart_cli:~$ broadcast: 0 uart_cli:~$ read: 0 uart_cli:~$ write_wo_resp: 1 uart_cli:~$ write: 1 uart_cli:~$ notify: 0 uart_cli:~$ indicate: 1 uart_cli:~$ auth_signed_wr: 0 uart_cli:~$ app: CENTRAL: Disconnected, handle: 0, reason: 0x13 uart_cli:~$ Just a recap for anyone else stumbling upon this problem: If a custom characteristic, inside a custom service, has a different base UUID, then it needs to be read specifically with sd_ble_gattc_read, this is done as described in the posts above. Since you read on a characteristic declaration it has more than 16 bytes, as Hung described. That just needs to be decoded correctly and you are good to go!

Hannu Hirvonen · Answer

Hello Dresse and Hung, 
 
 I'm fighting also with same kind of issue. Is this possible to somehow get this correction, so that I don't need to do same things again which has already done (by Dresse). 
 
 -Hannu-

Discovering a VS UUID Characterisic, but it shows UUID as 0

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