Scanning of Phy Coded advertising data on Android

RE: Scanning of Phy Coded advertising data on Android

Simonr — Tue, 05 Jan 2021 08:17:26 GMT

I'm sorry, but we have no such list, as the sheer number of phones that would require testing is too large to make a comprehensive list of this. Most of the latest high-end phones and flagship models the last couple of years. For example, the later OnePlus models, the Samsung S10 and newer, etc. It is in our backlog (for the nRFConnect app that is) to check whether the phone supports Coded PHY "correctly" or not, but this is not in place as of yet. Please look out for it in future updates.

Thank you for explaining your predicament, I think I understand, but I think you have a lot of trial and error in front of you to find this balance.

Best regards,

Simon

RE: Scanning of Phy Coded advertising data on Android

ifrz — Mon, 04 Jan 2021 17:02:12 GMT

Hi Simon

Tanks for the replay, I understand that the problem is whit my phone that cannot support the secondary PHY as coded and for that reason I cannot see the advertisement done in the secondary PHY, I guess I'll do the other approach that commented before. But we'll developing more Bluetooth 5 related projects in a near future, I have some nrf dongles with Bluetooth 5.2 that probably test for some precise indoor location project. It's possible to get a list of android devices (smartphone/tablet) that fully support all Bluetooth 5 features?

[quote userid="75734" url="~/f/nordic-q-a/70057/scanning-of-phy-coded-advertising-data-on-android/287264#287264"]Is there a specific reason you're using Coded PHY for these advertisement? I don't see how it's well suited here, as Coded PHY advertisements take ~8 times longer to do than on the Uncoded PHYs (1MBPS and 2MBPS). Are these sensor nodes located too far away from the scanning module(s)? [/quote]

Maybe not in the line of sight but keep in mind that it is a very noisy environment. Inside it's impossible to get GSM/GPS coverage, it's like a Faraday cage, that's why we use LoRa to communicate with the outside but even to communicate on the inside the noise are also quite big. The reason why we do not use LoRa for indoor communication is because of the low bandwidth, the communication with the outside does not matter if it is delayed but the indoor one has to be fast. We have tried Ble legacy and it did not offer as good coverage as Phy Coded, at this moment I have code it for the most extreme case, I know that with the lowest coding rate in the device and extended advertising I have the potential to cause the three advertising channels to become congested and with fast advertisement the 650mA node batteries are drained in 17 hours but it would be a question of adjusting it to find a good balance between coverage and transmission speed.

Regards

RE: Scanning of Phy Coded advertising data on Android

Simonr — Mon, 04 Jan 2021 13:55:12 GMT

The nRFConnect screenshot is reminiscent of an Android phone not supporting Coded PHY fully. Multiple phones state that they support Coded PHY in the app because the app checks this by checking the Android stack if it supports BLE 5.0, where Coded PHY is an optional feature.

The reason you're able to see these short periods of advertisements is because this is the amount of time the devces are advertising on the primary advertising channels (37, 38, & 39). The rest of the advertisement in Coded PHY advertising is done on secondary channels, which a phone not supporting Coded PHY will not be able to "see".

If you use a phone supporting Coded PHY you should be able to see a "complete" scan of Coded PHY advertisements as well.

Is there a specific reason you're using Coded PHY for these advertisement? I don't see how it's well suited here, as Coded PHY advertisements take ~8 times longer to do than on the Uncoded PHYs (1MBPS and 2MBPS). Are these sensor nodes located too far away from the scanning module(s)?

Best regards,

Simon