Disable scan response

RE: Disable scan response

run_ar — Thu, 27 Apr 2017 12:19:17 GMT

Sorry, my bad; not sure what I was thinking. Please try to just set the flag to: BLE_GAP_ADV_FLAG_BR_EDR_NOT_SUPPORTED (0x04). Note that some phones might not support a peripheral that doesn't send a scan response, even if it is just an empty reply.

RE: Disable scan response

Al Bundy — Mon, 10 Apr 2017 13:51:12 GMT

'You can use the the whitelist in limited discoverable mode.' Well if I set BLE_GAP_ADV_FLAGS_LE_ONLY_LIMITED_DISC_MODE instead of BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE I still get error 0x3201. According to one of yours earlier comments it means 'Use of Whitelist not permitted with discoverable advertising.'

RE: Disable scan response

Al Bundy — Fri, 07 Apr 2017 15:06:57 GMT

Mobile phone, or to be more precise multiple mobile phones. I still want all mobile phones to be able to connect to my beacon but do not want to sent SCAN RESPONSES. Is it possible with limited discoverable mode? I want to use whitelist for scan requests with one random address.

RE: Disable scan response

run_ar — Fri, 07 Apr 2017 14:23:15 GMT

You can use the the whitelist in limited discoverable mode. But what peer devices do you have?

RE: Disable scan response

Al Bundy — Fri, 07 Apr 2017 13:54:01 GMT

Can I disable SCAN RESPONSE in limited discoverable mode or there is no SCAN REQUEST at all in this mode?

RE: Disable scan response

run_ar — Fri, 07 Apr 2017 12:40:23 GMT

It's a core spec limitation: "The Host shall set the advertising filter policy to ‘process scan and connection requests from all devices’."
Note: You could use limited discoverable mode and just restart advertising when it times out.

I finally figured out why we still send a scan response even with 0 data length. Apparently it's common that the scanner will ignore advertisers that don't respond to scan requests, so your device wouldn't be discoverable at all. A bit inconvenient, but it is what it is.

RE: Disable scan response

Al Bundy — Fri, 31 Mar 2017 15:58:19 GMT

So it is not possible to filter SCAN REQUEST and accept BLE connections from any other devices? These 2 things seems to be totally independent

RE: Disable scan response

run_ar — Fri, 31 Mar 2017 14:27:40 GMT

Yes, it means: Use of Whitelist not permitted with discoverable advertising.

RE: Disable scan response

Al Bundy — Tue, 28 Mar 2017 13:14:50 GMT

In EDIT I have shown how I want to achieve my goal, unfortunately ad_ble_gap_adv_start returns 0x3201.

RE: Disable scan response

run_ar — Tue, 28 Mar 2017 12:38:15 GMT

To use the whitelist advertisement feature just provide a static address and configure the filter policy correctly (ble_gap_adv_params_t::fp)

RE: Disable scan response

Al Bundy — Mon, 27 Mar 2017 13:00:27 GMT

Last time I have tried to implement it I have end up with failure. I sniffed SCAN RESPONSEs anyway. I am going to try again, can you also try it? It is not so time consuming.

RE: Disable scan response

endnode — Mon, 27 Mar 2017 12:43:39 GMT

From what I read yes. What do you see on RF sniffer?;)

RE: Disable scan response

Al Bundy — Mon, 27 Mar 2017 12:31:17 GMT

Yes it will, but using whitelist should result in sending no SCAN_RSP at all?

RE: Disable scan response

endnode — Mon, 27 Mar 2017 11:22:40 GMT

But this will still send SCAN_RSP just with zero PDU lenght, won't it?

RE: Disable scan response

run_ar — Mon, 27 Mar 2017 11:00:08 GMT

If you don't want to send scan responses at all you can set p_sr_data og srdlen to 0 when calling sd_ble_gap_adv_data_set.

RE: Disable scan response

endnode — Mon, 27 Mar 2017 10:17:02 GMT

In that case yes, this GAP API flag should bring you what you want (sending SCAN_RSP only to SCAN_REQ from given MAC address). Have you already tested it?

RE: Disable scan response

Al Bundy — Mon, 27 Mar 2017 09:51:42 GMT

I do not want to avoid Rx window, I want to avoid sending scan response packet. I thought that when I use filter for scan request with random address then my beacon will send scan response packet only to that one specific address. Now my beacon sends scan response to every device that issue scan request. Am I wrong?

RE: Disable scan response

endnode — Sat, 25 Mar 2017 16:05:08 GMT

Hi,

You probably want to avoid Rx window after each Advertisement Tx packet, providing random address to the whitelist won't help you (Soft Device will still be listening). In that case you must use BLE_GAP_ADV_TYPE_ADV_NONCONN_IND (see this answer for more) but it has some side effects:

Soft Device won't allow you to set lower adv. interval then 100ms (in-line with BT SIG Core specification).
Soft Device won't listen for connection (again in-line with BT SIG Core).

If you don't like this variant, then you would need other BLE stack then Nordic Soft Device (and probably customize it as it might be enforcing these BT SIG rules as well).

Cheers