LAUNCHXL-CC26X2R1: ProjectZero: how to enable DataService notifications by default

kazola

Part Number: LAUNCHXL-CC26X2R1
Other Parts Discussed in Thread: CC2540

Tool/software:

Hi all,

Hope you are having a great Friday.

I would like my code to be modified so just after flashing it to the CC26X2R, the DataService notifications are enabled by default without the need for me to send a BLE frame to put a '1' to its configuration.

My code works fine if I enable them, but I want this done from the beginning.

How do I modify ProjectZero for this?

Thanks a lot.

4 months ago

0 David 3 months ago

TI__Genius 12925 points

Hello Kazola,

Thanks for reaching out.

Enabling notifications by default (from the peripheral) without the central triggering it while in a connection does not technically meet the Bluetooth spec. I would suggest taking a look at this thread: https://e2e.ti.com/support/wireless-connectivity/bluetooth-group/bluetooth/f/bluetooth-forum/1104751/cc2640-how-can-i-enable-the-characteristic-4-notification-in-the-simple-peripheral-project-by-default.

BR,

David.

0 kazola 3 months ago in reply to David

Guru 18515 points

Hi David!

I can understand it does not meet specifications.

Those links are for CC2540 so they are not very useful.

Is there a fast way using DataService_SetParameter to do this or directly modifying the attribute table? We are just doing performance tests, we do not care much about Bluetooth specs.

Thanks.

+1 David 3 months ago in reply to kazola

TI__Genius 12925 points

Hello Kazola,

I see. Although the links are for cc2540, the idea is similar: "...disregard the CCCD completely and just manually call GATT_Notification()". You can see the CCC validation done by the peripheral to confirm the central has enabled notifications (GATT_CLIENT_CFG_NOTIFY) inside this function: processExtMsgATT() located in icall_hci_tl.c for the simple_peripheral example found inside the SDK.

...
if ((value & GATT_CLIENT_CFG_NOTIFY) || (pNoti->handle == 0))
{
    stat = GATT_Notification(connHandle, pNoti, pBuf[2]);
    if((stat == SUCCESS) && (pNoti->pValue != NULL))
    {
        safeToDealloc = FALSE; // payload passed to GATT
        ...

BR,

David.

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LAUNCHXL-CC26X2R1: ProjectZero: how to enable DataService notifications by default