CCS/CC2640R2F: Multi primary services

Giuseppe_pe

Expert 1930 points

Part Number: CC2640R2F
Other Parts Discussed in Thread: LAUNCHXL-CC26X2R1, CC2540, PACKET-SNIFFER

Tool/software: Code Composer Studio

Hi,

In my code I have one primary service with 4 charcteristics (write,indicate,indicate,indicate) when I scan with BLE scanner app I connect to CC2640R2F and I see the list of service.

Now, I add another primary service with 4 charcteristics (write,indicate,write,indicate), when I scan with BLE scanner app I try to connect it, but the connection fail.

Can you help me to add a primary services?

I notice that also with only one primary service, when I add more attribute in the list (>23) the device doesn't connect.

Is there a max number of attribute in attribute list?

Thanks.

Best regards.

Giuseppe

over 6 years ago

0 IUsedToBeARealPerson (M-W) over 6 years ago

TI__Guru 58425 points

Hi,

I have assigned a expert to comment on this.

0 Eirik V over 6 years ago

TI__Guru 56590 points

Hello Guiseppe,

The RAM is mainly the limitation for number of attributes. There should be for plenty more if you use the standard simple_peripheral example.

Please share the service source file and I can take a look.

You can also sniff the air traffic to figure out why the connection drop:

PACKET SNIFFER:
------------------------------------------------------------------------------------------
TI BLE Packet sniffer is a low cost option that support BLE 4.0. You can download it here:
www.ti.com/.../PACKET-SNIFFER

There are two versions of the tool depending on which sniffer front end you want to use.
You need to install Wireshark to use PACKET-SNIFFER-2.

PACKET-SNIFFER-2 with LAUNCHXL-CC26X2R1 (www.ti.com/.../LAUNCHXL-CC26X2R1).
PACKET-SNIFFER with CC2540 USB Dongle (www.ti.com/.../CC2540EMK-USB).

Here are a few third party packet sniffers that also require a physical sniffer you would need to purchase:
Ellisys (www.ellisys.com/.../bluetooth.php)
Frontline (www.fte.com/.../BPAlowenergy.aspx)

Other options may be out there.

0 Giuseppe_pe over 6 years ago in reply to Eirik V

Expert 1930 points

Hi,

attached simple_gatt_profile.h and simple_gatt_profile.c with a primary service and 4 attributes that work and where I have to add another primary service with 4 other attributes.gatt_profile.zip

Thanks.

Best regards.

Giuseppe

0 Giuseppe_pe over 6 years ago in reply to Giuseppe_pe

Expert 1930 points

Hi,

attached the same files as before, but I added 3 characteristics on the same primary service :

confprofile_char1 write

confprofile_char2 indicate

confprofile_char3 write.

If I add only confprofile_char1 the device services are discovered from BLE scanner app.

If I add confprofile_char1 + confprofile_char2 or confprofile_char1 + confprofile_char3 or confprofile_char1 + confprofile_char2 + confprofile_char3,

the services are not discovered.

Best regards.

Giuseppesimple_gatt.zip

0 Eirik V over 6 years ago in reply to Giuseppe_pe

TI__Guru 56590 points

Hello Giuseppe,

There might be issues with with the bluetooth cache on yout phone, please review section below in FAQ:

Q: When switching sample applications on my board or LaunchPad, my iOS or Android device is not able to "see" new Characteristics or Services

https://e2e.ti.com/support/wireless-connectivity/bluetooth/f/538/t/404236

You can use Btool instead to discover the services:

http://dev.ti.com/tirex/explore/content/simplelink_academy_cc2640r2sdk_3_40_02_00/modules/blestack/ble_01_basic/ble_01_basic.html#task-2-connect-and-navigate-exposed-services

0 Eirik V over 6 years ago in reply to Giuseppe_pe

TI__Guru 56590 points

Did you see the Example service generator here?

dev.ti.com/.../ble_01_custom_profile.html

0 Eirik V over 6 years ago in reply to Giuseppe_pe

TI__Guru 56590 points

Also I see that you define all the characteristic value attributes of length 255. You need to adjust the ATT_MTU size for this to work efficiently and then set the indication characteristic value length to maxim um ATT_MTU - 3 bytes.

https://e2e.ti.com/support/wireless-connectivity/bluetooth/f/538/p/549857/2011171#2011171

http://dev.ti.com/tirex/explore/content/simplelink_cc2640r2_sdk_3_40_00_10/docs/blestack/ble_user_guide/html/ble-stack-3.x/gatt.html?highlight=mtu#maximum-transmission-unit-mtu

To test I would even just start at for example 20 bytes and make sure the service works as expected before you increase the attribute value length.

0 Giuseppe_pe over 6 years ago in reply to Eirik V

Expert 1930 points

Hi,

ok, thanks I reducece the number of bytes and all new characteristics are added.

Now I try to define another primary service and I try to put the new characteristics inside it.

But, when I scan with the app I see two primary service, but all characteristivcs are in the first.

To put the first 4 characteristics in the first primary service and the second 4 in the second primary service I change the simpleProfileAttrTbl in this way:

static gattAttribute_t simpleProfileAttrTbl[SERVAPP_NUM_ATTR_SUPPORTED] =
{

{ primary service 1},

{ characteristic 1},

{ characteristic 2},

{ characteristic 3},

{ characteristic 4},

{ primary service 2},

{ characteristic_a 1},

{ characteristic_a 2},

{ characteristic_a 3},

{ characteristic_a 4},

}

but it doesn't seem enough.

what else should i do in the code?

Thanks.

Best regards.

Giuseppe

0 Eirik V over 6 years ago in reply to Giuseppe_pe

TI__Guru 56590 points

For separate services create separate source files with their own initialization like its done in the Project Zero example where led_service.c, button_service.c, etc must all be separately implemented

// Add services to GATT server and give ID of this task for Indication acks.
  LedService_AddService( selfEntity );
  ButtonService_AddService( selfEntity );
  DataService_AddService( selfEntity );

  // Register callbacks with the generated services that
  // can generate events (writes received) to the application
  LedService_RegisterAppCBs( &user_LED_ServiceCBs );
  ButtonService_RegisterAppCBs( &user_Button_ServiceCBs );
  DataService_RegisterAppCBs( &user_Data_ServiceCBs );

Bluetooth®︎

Bluetooth forum

CCS/CC2640R2F: Multi primary services