How can the Peripheral connect with Central only by using directed Broadcast

[Xphiting]

Hi

I'm using SKD16.0.0 and S132, and I want to realize that peripherals can only connect to a center with a known MAC address through directed advertising.How should I implement this?

• Where the central MAC address is known. 
• The peripheral address is unknown.
• Use directed advertising directly
• No pairing or binding is required.

Best regards

Xft

[Hung Bui]

Hi XFT, 

- You can get the MAC address of a central device when you connect to the central device (BLE_GAP_EVT_CONNECTED event). This only applied for central device that use static address. 

- Please have a look at our ble_app_mouse example. In the example we use directed advertising after a disconnection. In the example we use bonding but you can think of skipping that if you don't plan to use bonding. When configuring the advertising set, you need to select the adv_params.properties.type = BLE_GAP_ADV_TYPE_CONNECTABLE_NONSCANNABLE_DIRECTED or BLE_GAP_ADV_TYPE_CONNECTABLE_NONSCANNABLE_DIRECTED_HIGH_DUTY_CYCLE

[Xphiting]

Hi Hung Bui,

Thank you for your answer, but it does not fulfill my idea.Because I already knew the MAC address of the central in advance, I wanted to communicate with the specified central from the beginning via directed advertising, rather than using directed advertising after the disconnect.Can you provide a solution to this idea?

[Hung Bui]

If you already have the address, you can fill that in the p_peer_addr field in ble_gap_adv_params_t struct. And then start directed advertising. Please study the ble_advertising.c library we have. 

[Xphiting]

 I am a newbie in BLE.Could you please provide a more detailed procedure for configuring directed advertising.

Thank you.

[Hung Bui]

Please study the ble_app_mouse example and get familiar with our APIs. 
I wouldn't suggest you to go straight into advanced feature without basic knowledge about the softdevice and the libraries. 

[Xphiting]

Hi

I have configured the peripheral to broadcast directionally. How do I configure scanning in the central?

Thank you.

[Hung Bui]

Hi Xft, 

I'm sorry for late response. 

You can just do scanning normally. Directed advertising packet is similar to normal connectable advertising packet with only 1 bit difference and the interval is shorter. Have look here: https://devzone.nordicsemi.com/f/nordic-q-a/41407/nrf51-scan-for-directed-advertising

[Xphiting]

Hi  Hung Bui

As shown in my sniffer, directed advertising has already begun.

Advertising Address and Initator Address are both correct.

But, no connection was established while using a normal scan on the central via using the NRF_BLE_SCAN_ADDR_FILTER.