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]

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.

[Hung Bui]

Could post the code where you do scanning and connecting ? 

Please try testing by doing this : 

1. Just do normal advertising and check if your scanning parameter works. Meaning you can scan for the advertising packet when the advertising in normal advertising mode. 

2. Just do only scanning, not connecting, and check which advertising packets you receive. 

There is a chance that the address you input into the scan parameter was not correct (wrong endianess for example)

[Xphiting]

Thank you very much for your time and reply.

I have found the direcetd advertising packet in the BLE_GAP_EVT_ADV_REPORT and have established the connection.

Thank you again.