Scan Response

RE: Scan Response

letter57 — Tue, 30 Aug 2016 17:24:39 GMT

I have seen the question 2 in 『Bluetooth Low Energy The Developer’s Handbook』,the author is "Robin Heydon".

In the "Active Scanning" chapter

『In active scanning, whenever a new device is discovered by the Link Layer, a scan request is sent to the advertising device, and a scan response is expected in reply. Both these scan requests and response packets are transmitted on the advertising channel. For active scanning to work efficiently, the data in the scan response must be mostly static because this data is expensive in terms of energy expended to retrieve due to the additional two packets that are transmitted or received. The data in the original advertising packet, however, can change regularly because this will always be received.』

RE: Scan Response

Petter Myhre — Mon, 13 Jun 2016 07:28:23 GMT

How to setup a scan response is included in this tutorial.

RE: Scan Response

Defozoo — Sat, 11 Jun 2016 17:15:32 GMT

Can you provide some code, please?

RE: Scan Response

RK — Thu, 07 Jan 2016 01:25:01 GMT

it does so state. Nothing forces you to actually do that but in generally it's recommended that you do, especially if you ever want it to be a 'real product' or use it with any kind of standard scanning central which will read and interpret those two bytes as the manu id.

RE: Scan Response

WestCoastDaz — Wed, 06 Jan 2016 23:38:15 GMT

RK,

Thanks for the reply! One final question if I am using the manufacturing specific data then SIG states that the company identifer be the first 2 octets correct?

RE: Scan Response

RK — Wed, 06 Jan 2016 23:28:07 GMT

Yes - the scan response is more usually used in things which are connectable than aren't, but either works.
I don't know where you read that, it's not true, you can change every piece of data in the adverting and scan response on a constant basis if you like, have a scan response, not have one later. Whether the device scanning you manages to handle and report all those changes is up to the device scanning you.
possibly not - but it's trivial - just encode the scan response in the same way you encode the advertising data and then add the encoded data to the p_sr_data and srdlen of the sd_ble_gap_adv_data_set(). Or if you're using the Advertising and Scan Response encoder library, one layer higher, the unencoded data into the last argument of ble_adv_data_set(), p_srdata, if if you're using the entire advertising module, ble_advertising_init() with a non-NULL p_srdata second paramter.