Time Synchronization Between BLE devices only after they have established a connection.

[dcooperch]

I took a look at this article here: Wireless timer synchronization among nRF5 devices and it looks promising for what I need.  However, I have a couple of questions.  Specifically with the Zephyr sample.

I plan on having a star topology with one central and multiple peripherals.  The sample code does not differentiate between the two roles.  In fact, the sample code starts advertising right away in the main function and it appears to have a partial/incomplete example of how to use the UART service. 

I am planning on having one central device transmit beacons only to BLE advertising peripherals that I have already intentionally established a connection with. How could I modify the mentioned example to only direct the beacon packets to those peripherals?

Also, for starters, I plan on combining the time sync logic with the Central UART and Peripheral UART samples for now but may plan on creating my own custom services in the near future.  And I want to make sure that the time synchronization sample will still work.

Any help would be greatly appreciated.

[Susheel Nuguru]

Hi Daniel,

I think it wont be that hard to change the behavior to broadcast the same data that we send in the notifications. The challenge here is to configure the broadcast data same as the notification data. Maybe the adv data size is too small?  The author of that module and blog is away on parental leave so I cannot get more insights into it easily either. But in short, the challenge seems to fir the notification data in adv data and do  start advertiser and send notification at the same configured time interval.

[mej7000]

dcooperch said:

 Wireless timer synchronization among nRF5 devices

I have the same need as the OP for either a Star Topology over Shockburst or BLE Mesh (TBD).

Is there a Zephyr sample for wireless time sync?