Tutorial Characteristic Master example

[Francesca]

Hi, I'm trying to notify the temperature value with Tutorial Characteristic Master example. But log shows me this rows when I try to read the Descriptor Client Characteristic Configuration:

• Read Response received from descr. 00002902-0000-1000-8000-00805f9b34fb, value: (0x) 00-00

• "Notifications and indications disabled" received

Why don't I receive the temperature value? Why is notification disabled? I followed correctly all the steps explained here: devzone.nordicsemi.com/.../ On the contrary I've not problems to add a characteristic to the service. I'm using S130, nRF51822 and nRF connect for Android. Thanks!

[FormerMember]

From what I understand, you are setting up a peripheral device?

If notifications are enabled, the value of the CCCD for the given characteristic should be 0x01. The read response tells that notifications are not enabled.

What do you do in nRF Connect to enabled notifications?

Update 30.06.2017: This is how to enable notifications:

[Francesca]

Yes, I'm setting up a peripheral device. Actually I don't enable notifications using nRF connect but the example enables them writing this code:

// OUR_JOB: Step 3.A, Configuring Client Characteristic Configuration Descriptor metadata and add to char_md structure
		ble_gatts_attr_md_t cccd_md;
		memset(&cccd_md, 0, sizeof(cccd_md));
		BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.read_perm);
		BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cccd_md.write_perm);
		cccd_md.vloc                = BLE_GATTS_VLOC_STACK;    
		char_md.p_cccd_md           = &cccd_md;
		char_md.char_props.notify   = 1;

[FormerMember]

A peripheral device cannot enable notifications for it's own characteristics.

char_md.char_props.notify = 1; sets the characteristic notification property to '1', it means the during a service discovery, a central will see that this characteristic has the notification property. It can be useful to read more here.

Enabling/disabling notifications has to be done by the central.

[Francesca]

How can I enable notifications using nRF connect? In this case the central is a smartphone. Enabling notifications, will it be possible to receive data about temperature?

[FormerMember]

I have updated the answer, showing how to enable notifications.