Changing advertisement data in every packet

RE: Changing advertisement data in every packet

tomole — Mon, 24 Oct 2016 12:41:22 GMT

Yes, this is a beacon application. I am not connecting devices to the nRF51, but in next versions of my app it can be needed. I want to advertise my dynamic data which come from another part of my application. I can send 62 bytes in case I don't make connections. Am I right? Thank you for the links. I have already used BLE tutorial.

RE: Changing advertisement data in every packet

Sigurd — Thu, 20 Oct 2016 10:30:41 GMT

Is this a kind of beacon application? You are not connecting any devices to the nRF51, only advertising? What kind of data are you advertising? Is it temperature or battery voltage that is changing?

The advertising packet only supports up to 31 bytes, so the scan response data packet is an optional "secondary" advertising payload which allows scanning devices that detect an advertising device to request a second advertising packet. This allows you to send two advertising frames with a total payload of 62 bytes.

See this tutorial and this blog post about advertising.

RE: Changing advertisement data in every packet

tomole — Thu, 20 Oct 2016 10:21:55 GMT

Thank you, this is a very good option. I am looking forward for the link. I am using nRF51. For my application every packet is important and I need to count sent packets, give them kind of id and markers. I am not very clear what do you mean by puting data in the scan response packet. Right now, I don't have problems with packet size, but in other versions of application it may be an issue.

RE: Changing advertisement data in every packet

Sigurd — Thu, 20 Oct 2016 09:24:22 GMT

I can create a Keil example for you if you want. What chip are using? nRF51 or nRF52? Why do you need to change advertisement data every packet? You can also put data in the scan response packet, if you can't fit all the data in the advertisement packet.

RE: Changing advertisement data in every packet

tomole — Wed, 19 Oct 2016 14:23:16 GMT

Dear Sigourd, Thank you for a fast answer. I face some problems with GCC. Are there any Keil example projects for that?

RE: Changing advertisement data in every packet

Sigurd — Thu, 13 Oct 2016 14:38:46 GMT

The solution here is to use radio notifications. You will have to change the advertisement packet every time the radio has been active, which typically is after every advertisement interval. You will have to setup a callback function in ble_radio_notification_init(…) that changes the advertisement packet.

A user has uploaded his implementation of this solution here, where he switches between different eddystone-format advertising packets using the callback function eddystone_interleave(..).