Extended advertisement scanner drop messages

RE: Extended advertisement scanner drop messages

Kenneth — Wed, 04 May 2022 12:21:37 GMT

I would assume that after receiving an ext advertising it will return to scanning for any advertisment/ext advertisement:
https://devzone.nordicsemi.com/guides/nrf-connect-sdk-guides/b/software/posts/building-a-ble-application-on-ncs-sdk---contrasting-to-softdevice-based-ble-applications---part-2-central-role#mcetoc_1f4ua7m2t0

Kenneth

RE: Extended advertisement scanner drop messages

Ashishsult — Wed, 04 May 2022 08:35:42 GMT

Hi Kenneth, Thanks for your answer. I also want to know how the scanner would behave when we have multiple Ext Advertisers.

RE: Extended advertisement scanner drop messages

Ashishsult — Thu, 21 Apr 2022 08:40:15 GMT

HI Kenneth, I test with both the node placed next to each other and therefore, I was thinking if that is normal.

Plus, I want to know how the scanner would behave when we have multiple Ext Advertisers. Is it possible that it receive only from 1st node for some time and doesn't receive packets from other nodes. Later, it can switch to another node.

RE: Extended advertisement scanner drop messages

Kenneth — Thu, 21 Apr 2022 08:03:29 GMT

This looks like normal packet loss due to interference. You can try to move the boards closer togheter and see if the packet loss is reduced.

Kenneth

RE: Extended advertisement scanner drop messages

Ashishsult — Wed, 20 Apr 2022 11:33:11 GMT

Hi Kenneth,

Yes, I observed that the power consumption for Nordic SDK controller is higher as the radio is always seems to be in listening mode. But still it looses packet reception (ppk is attached).

Data rate is 1s, and pin 2 toggled everytime scanner receive data packet

devzone.nordicsemi.com/.../ext_5F00_nordixsdk_5F00_dr1s.zip

RE: Extended advertisement scanner drop messages

Kenneth — Wed, 20 Apr 2022 09:17:42 GMT

Is there any different if you use the softdevice controller vs. the zephyr controller? E.g. in prj.conf

CONFIG_BT_LL_SOFTDEVICE=y

vs.

CONFIG_BT_LL_SW_SPLIT=y

You may also need to enable CONFIG_BT_CTLR_ADV_EXT=y to support extended advertising with the zephyr controller.

Best regards,
Kenneth

RE: Extended advertisement scanner drop messages

Ashishsult — Mon, 11 Apr 2022 23:55:48 GMT

Hi Kenneth,

Here is the ppk file where Digital Channel 0 toggling represents the arrival of filtered packet.

It is observed in the start when the Advertiser is not active, the scanner scans for 100% time but once the advertiser starts sending the Extended ADV at an interval of 500ms, the scanner starts reducing the scan window automatically. At some point it also reduced to ~ 5 ms (check at 2:47 timestamp) and then back to 100% after ~500ms.

I do not understand this behaviour, is it expected by the scanner?

devzone.nordicsemi.com/.../collision500mssingledevicesh.zip

RE: Extended advertisement scanner drop messages

Ashishsult — Mon, 11 Apr 2022 11:15:13 GMT

Hi Kenneth,

It is already BT_LE_SCAN_OPT_NONE, as below configuration

struct bt_le_scan_param scan_param = {
.type = BT_LE_SCAN_TYPE_PASSIVE,
.interval = BT_GAP_SCAN_SLOW_INTERVAL_2,
.window = BT_GAP_SCAN_SLOW_INTERVAL_2,
.options = BT_LE_SCAN_OPT_NONE
};

About the PPK, I will check it and post it soon.

Moreover, can you explain how should the scanner behave when we have more than one broadcast devices?

RE: Extended advertisement scanner drop messages

Kenneth — Fri, 08 Apr 2022 12:29:49 GMT

If you have the possibility it could be interesting to measure the current consumption during this period (e.g. using Nordic PPK2), to understand if it's actively scanning or if it's in sleep for some reason. When you start scanning, can you check if you have set BT_LE_SCAN_OPT_FILTER_DUPLICATE or BT_LE_SCAN_OPT_NONE? I recommend to try BT_LE_SCAN_OPT_NONE to ensure the packets are not filtered somehow.

Kenneth