Advertising/Scanning Problems

[Yaroslav]

Issue is similar to devzone.nordicsemi.com/.../

I'm developing an application based on latest SoftDevice 130_1.0.0 and using two or more DevKits. My application starts advertising and scanning simultaneously with parameters:

	adv_params.type        = BLE_GAP_ADV_TYPE_ADV_IND;
	adv_params.p_peer_addr = NULL;                           			
	adv_params.fp          = BLE_GAP_ADV_FP_ANY;
	adv_params.interval    = BLE_GAP_ADV_INTERVAL_MIN;
	adv_params.timeout     = BLE_GAP_ADV_TIMEOUT_GENERAL_UNLIMITED;

	if(adv_mode == LIGO_ADVERT_MODE_CONNECTED)
	{		
		adv_params.type		= BLE_GAP_ADV_TYPE_ADV_NONCONN_IND;
		adv_params.interval	= BLE_GAP_ADV_NONCON_INTERVAL_MIN;
	}

	scan_param.active = 0;
    scan_param.selective = 0;
    scan_param.p_whitelist = NULL;
    scan_param.timeout = 0;
    scan_param.interval = 0x03C0;		// 600 ms
    scan_param.window = 0x0140;		// 200 ms

Each board using LED indicates receiving advertise reports.

So, I've noticed next:

1. When I reset(or power on) two board at the same time - both boards don't indicate anything, it means there are no incoming advertising packets. Seems, nRF during scan doesn't advertise.

2. When I reset(or power on) two board at different time - they both work fine but after some time (adout 15-30 min) I see that advertising's appear much rarely up to total stopping receiving adv packets for few minutes and then I see advertise packets again.

3. When I set next scan interval = window, like:

   scan_param.interval = 0x03C0; // 600 ms scan_param.window = 0x03C0; // 600 ms I don't see any advertising using nRF MasterControlPanel for PC and/or for smartphone. Also both boards don't indicate anything.

4. When I start a app_timer() in advertising report handler I notice that scanning activity becomes worst - I can see indications very rare.

So, could you explain this behavior?

[Susheel Nuguru]

1. The device cannot scan and advertise at the same time, but they are multiplexed over the timeline.

2)when you reset boards at different time, then scanner and advertiser on each boards start at different time. So the scanner on one board can see the advertiser on the other. This has also happened due to many factor, like how far did you reset these boards, scan interval and advertising interval.