RX Radio Stopped for 100uS after each adv packet on scanner

RE: RX Radio Stopped for 100uS after each adv packet on scanner

Einar Thorsrud — Wed, 15 Jan 2020 18:52:59 GMT

Hi,

Which SoftDevice version are you using? Older SoftDevices did resume scanning automatically, but from version 6 (if I don't remember wrong) this has to be done by the application. However, you may not notice it if you use the scan module since this does it for you (you can search for sd_ble_gap_scan_start in nrf_ble_scan.c to see how it is used).

I cannot think of any other way to speed this up than to call sd_ble_gap_scan_start() as soon as possible (directly or via a SDK library)

RE: RX Radio Stopped for 100uS after each adv packet on scanner

wozix — Wed, 15 Jan 2020 18:46:23 GMT

Hi Einar, thanks a lot for your reply.

I am not restarting the scan inside the adv report event so this must be done by the Softdevice. I tried to manually enable the scan again while inside the event (the first thing I do) but I see the same delay of 93uS before the scan starts again. Is there any way to make this period shorter? Is there any configuration I am missing?

RE: RX Radio Stopped for 100uS after each adv packet on scanner

Einar Thorsrud — Wed, 15 Jan 2020 18:38:43 GMT

Hi,

Yes, there is a small time before starting scanning again after receiving an advertisement packet. In this case, The application has to restart/continue scanning, and that is typically done when receiving an advertising report event. You will miss any advertisement packets on air during this time. However, there are several other reasons why you could miss an advertisement packet as well, so you should never base a system on the assumption that you can receive (almost) all advertisement packets.