BLE coded phy scan get twice the same ADV

[Prayam]

Hello,

I've seen when ADV interval is near than 1 second, the sniffer cacth the same adv twice in diferent channels, but if the adv interval is near to 50 ms the sniffer only cacht 1 per ADV,  and athother question, if adv is send every 800ms I capture the adv every 800ms and the same adv 400ms after.  I using the same code example for long range  blog.nordicsemi.com/.../tested-by-nordic-bluetooth-long-range

[Kenneth]

I will see if someone can comment on your observation from the developers. I presume you are using the latest nRF sniffer (as of today that is v3.1): https://www.nordicsemi.com/Software-and-tools/Development-Tools/nRF-Sniffer-for-Bluetooth-LE 

[Prayam]

I'm using as sniffer/scaner another nrf52840 DK with long range test from your example: 

 devzone.nordicsemi.com/.../testing-long-range-coded-phy-with-nordic-solution-it-simply-works-922075585

[Kenneth]

Thanks for the clarification, I was thinking you were using our nRF sniffer tool. In your case you are not using our nRF sniffer tool, so disregard my previous comment.

During normal scanning the amount of received advertisement packets will depend on the scan window and interval, every scan interval the radio will switch to a new channel and scan for the period set by the window.

So in your case you likely need to modify the scan window and interval.

[Prayam]

Ok, can you do a scheme of what is the correct scan window for 50ms and for 800ms, and what i get after modified that? In my code i have the same time for scan window and scan interval, i misunderstood that if both are equal ,the scanner is ever scanning, therefore the time inst important

thanks!

[Kenneth]

This is a trade-off between current consumption, time to discover, other BLE links that you may have active at the same time, and potentially also interference that may be present in the area. If you know the maximum advertisement interval is 800ms, and you don't have any current consumption limitations, and there are no other active BLE links, then I would use 1sec for both window and interval.

Kenneth

[Prayam]

I´d adjust 800ms ADV for 1sec scanner, i get twice the same ADV,  80ms ADV to 100ms of scanner and 50ms adv for 70ms scanner all of that both window and interval. I have always the same result get ADVs on scanner twice. this is the correct result or not?

[Prayam]

hi! any progress with this?