Periodic advertising data

[DanisXZ]

Hi,

I am trying to understand periodic advertising and some basic questions:

I am using periodic_adv example from the NCS.

1. I see teo ADV data defined in the file as shown below. How will this data be used ? 
   
   

When I used wireshark I can see "TEST PERIODIC ADVERTISING" in AUX_ADV_IND packet, but should not the ADV data be in the AUX_SYNC_IND packets ? 

The AUX_SYNC_IND packets shows ADV_DATA but I cannot match the data given in the code.

     2. The periodic adv example keeps changing the ble address. How can I keep the address static-random which will not change ?

     3. On wireshark, when I select the device, then I can only see the AUX_SYNC_IND packets. Why is this so ?

[Amanda Hsieh]

Hi, 

1. The periodic_adv example starts Extended Advertising with the device name package, so it comes with the AUX_ADV_IND. See this line. Then BT_DATA_MANUFACTURER_DATA is set to the periodic advertising data with this line, so it comes with the AUX_SYNC_SUBEVENT_IND. 

2. You can replace BT_LE_EXT_ADV_NCONN with BT_LE_EXT_ADV_NCONN_IDENTITY.

diff --git a/samples/bluetooth/periodic_adv/src/main.c b/samples/bluetooth/periodic_adv/src/main.c
index a927c82e16c..425eccdbae3 100644
--- a/samples/bluetooth/periodic_adv/src/main.c
+++ b/samples/bluetooth/periodic_adv/src/main.c
@@ -31,7 +31,8 @@ int main(void)
        }

        /* Create a non-connectable advertising set */
-       err = bt_le_ext_adv_create(BT_LE_EXT_ADV_NCONN, NULL, &adv);
+
+       err = bt_le_ext_adv_create(BT_LE_EXT_ADV_NCONN_IDENTITY, NULL, &adv);
        if (err) {
                printk("Failed to create advertising set (err %d)\n", err);
                return 0;

3. When you select a device in Wireshark, you're essentially synchronizing with its periodic advertising train. The sniffer follows the periodic advertising and subscribes to the subevent, which is why you're seeing the AUX_SYNC_IND packets nRF Sniffer for Bluetooth LE guide.

Regards,
Amanda H.

[DanisXZ]

Thank you Amanda Hsieh  for your reply.

Why am I not seeing the periodic adv data in the sniffer ?

[Sigurd]

Hi!

Could you save and upload the sniffer file?