RE: Using Scan Request as a means of acknowledging beacon sensors advertisement

Rj_bro — Wed, 19 Jun 2019 13:08:09 GMT

Actually in advertising side, you have two parameters named Min Interval and Maximum Interval, minimum interval is time for only advertising packet to be sent and maximum interval includes both advertising packet and scan response packet to be sent. you can play around with that to change the timings. Similarlly you have scanning window and scanning interval on the central device. if you set both of them equally it will scan continuously.

You can set the peripheral device not to send scan response even though it receives scan request, all you need to do is while setting data for advertising and scan-response you can send NULL pointer in place of scan response pointer. But, in central device if you send scan request it will definetaly wait for scan response(I think playing with scanning window you can neglect the search for scanning response). But modifying the scan request is not possible.

I think this will help you, but i am not sure. Sorry if i am worng.

RE: Using Scan Request as a means of acknowledging beacon sensors advertisement

bjorn-spockeli — Mon, 03 Sep 2018 09:35:16 GMT

Hi Eric,

Q1: Yes, if the peripheral is advertising as a scannable device, then the peripheral will turn on its receiver after every advertisment packet.

Q2: It is possible to reconfigure the advertisement data so that the peripheral stops advertising as a scannable device and starts advertising as a non-scannable device. As far as I know there is no way to send scan requests as a central without scanning for advertisement packets first

[quote user=""] And although similar acknowledge functionality can be achieve with real GATT connections via Indications, actual GATT connections would consume too much power. [/quote]

This is not entirely correct as the current consumption in a connection versus broadcasting is highly application specific. As you already pointed out advertising will send the same data on 3 channels every advertisment interval and in a connection its only sent on one channel. Hence, an advertisement interval of 3 seconds will be the same as being in a connection with connection interval of 1 seconds in terms of current consumption.
In addition you may also set the link slave latency which allows the peripheral to only reply to every 2, 5, 10 or n-th packet if it does not have any data to send to the central.

Best regards

Bjørn