Can I enable notification in my ble peripheral?

RE: Can I enable notification in my ble peripheral?

Ulrich Myhre — Tue, 29 Jul 2014 18:32:01 GMT

If you have previously enabled notifications and bonded, the Quintic device will have to remember the state of the CCCD. You need to look into the device manager in thr SDK or the sys_attr_set() and get() functions to replicate this.

RE: Can I enable notification in my ble peripheral?

gootoomoon — Tue, 29 Jul 2014 06:30:49 GMT

Are you sure MCP will not automaticanlly enable notification? In the first picture ,"Quintic" device is enable notification by MCP just when I select the device without click "enable services" botton, that why I confused. And I need to implement this func in my nrf51822 device. But always failure.

RE: Can I enable notification in my ble peripheral?

Ulrich Myhre — Tue, 29 Jul 2014 04:08:09 GMT

Enabling/disabling for notifications and indications is strictly done from the peer device using a GATT Write operation. If the two devices are bonded, they are required to retain the CCCD state between connections. The default value should always be 0, i.e. no indications or notifications allowed.

The Master Control Panel does not automatically write to CCCDs unless you click the "enable services"-button or manually write e.g. 01-00 to the descriptor. A peer device that is interested in consuming the data would, on the other hand, automatically write to the descriptor to start getting data flowing. The MCP in general will not do much unless you specifically click certain buttons, so it is strictly for testing and debugging.

RE: Can I enable notification in my ble peripheral?

scytulip — Tue, 29 Jul 2014 03:51:54 GMT

I read ble_hrs.c. In "on_hrm_cccd_write" function, only a flag is set/unset. There's no code for stopping transmission. So I think this service keeps on sending data even the notification is turned off. Disabling/enabling service is done by the Android App?

You can check the code of MPC or nRF Toolbox to confirm that.

RE: Can I enable notification in my ble peripheral?

gootoomoon — Tue, 29 Jul 2014 03:33:51 GMT

Handle the client characteristic in nrf51822 device or in Android APP? I am so confused.

RE: Can I enable notification in my ble peripheral?

scytulip — Tue, 29 Jul 2014 01:52:34 GMT

MPC's "Enable Service" just works for test purpose.

Your service is enabled automatically when it connects to your cellphone, If you're using those BLE service API written by NordicSemi, such as ble_hrs.h, ble_bas.h, ble_dis.h, etc.

However, if you're writing your own service, you should handle the client characteristic configuration event correctly.