Unable to detect nRF52833 with Peripheral Coded PHY

RE: Unable to detect nRF52833 with Peripheral Coded PHY

Simonr — Thu, 22 Sep 2022 12:55:20 GMT

As there are no follow ups for now, I'll close this case as we're moving away from the initial subject of this ticket. Please create a new ticket if you have any other questions.

Best regards,

Simon

RE: Unable to detect nRF52833 with Peripheral Coded PHY

adam_atmo — Thu, 22 Sep 2022 07:48:54 GMT

Great, thanks Simon.

RE: Unable to detect nRF52833 with Peripheral Coded PHY

Simonr — Wed, 21 Sep 2022 13:35:41 GMT

Hi again Adam

This is better explained in the Coded PHY NovelBits blog post where you can see that the Coding Indicator is larder in Coded PHY than in the Uncoded ones, but the payload is still the same. I just takes longer to transmit, as it takes ~8 times as long to transmit.

Best regards,

Simon

RE: Unable to detect nRF52833 with Peripheral Coded PHY

adam_atmo — Wed, 21 Sep 2022 01:46:06 GMT

Hi Simon,

Thanks for the explanation.

Can I also please clarify the following: is the payload size of Coded PHY advertising packets smaller than that of LE 1M or 2M packets because of the additional bits used for FEC?

Thanks,

Adam

RE: Unable to detect nRF52833 with Peripheral Coded PHY

Simonr — Tue, 20 Sep 2022 06:35:39 GMT

Hi Adam

Scanning on the Coded PHY requires extended advertising because the Coded PHY uses both the primary channels (37, 38 and 39) to indicate an advertisement, as well as the secondary channels where the actual payload is. The secondary channels are required in order to get the increased range that Coded PHY provides, as these generally have less interference on them than the primary channels. Legacy advertising/scanning can not be used to connect in Coded PHY.

The phones Joakim mention all support Coded PHY, but not necessarily scanning and connecting in Coded PHY, as that is an optional feature in the specification. I'll let him know so he can update his reply.

Best regards,

Simon

RE: Unable to detect nRF52833 with Peripheral Coded PHY

adam_atmo — Mon, 19 Sep 2022 11:20:09 GMT

Hi Simon,

Perhaps you are right. Once connected, I was able to update the PHY to Coded PHY. The only change I made to the code was adding a few lines in the proj.conf file. Does that sound right to you?

Also, why does advertising on Coded PHY require extended advertising? Can’t legacy advertising be used?

This is where I saw the Coded PHY is supported.

Adam

RE: Unable to detect nRF52833 with Peripheral Coded PHY

Simonr — Mon, 19 Sep 2022 10:43:59 GMT

Hi Adam

Can you link to where you found that the Pixel 4 supports scanning in Coded PHY? I found this discussion in our Android BLE library on Github, where one of our developers confirm that the Pixel 4 does not support scanning on the Coded PHY. It will be able to support a connection in Coded PHY, but that connection will have to be initialized and created in the 1MBPS PHY initially I'm afraid.

Best regards,

Simon

RE: Unable to detect nRF52833 with Peripheral Coded PHY

adam_atmo — Sun, 18 Sep 2022 10:56:52 GMT

Hi Simon,

Any suggestions as to what I should do? I cannot detect any peripheral when scanning from the Pixel 4 (Coded PHY is supported). Also, I cannot see three broken-up advertising signals as per your image.

The README says that this application should be tested with another nRF device using the Central sample. Surely it should work with the Android device using nRF Connect?

Could the issue be that the Android does not support scanning for peripherals that use extended advertising?

Thanks

Adam

RE: Unable to detect nRF52833 with Peripheral Coded PHY

adam_atmo — Fri, 16 Sep 2022 12:58:11 GMT

Hi Simon,

It’s the pixel 4 apologies - it apparently does support coded PHY according to list published on a Nordic dev zone forum.

Adam

RE: Unable to detect nRF52833 with Peripheral Coded PHY

Simonr — Fri, 16 Sep 2022 11:42:46 GMT

Are you sure the Google Pixel 3 supports the Coded PHY? It's not a given in any phone supporting Bluetooth 5.0 unfortunately, as it is an optional feature. And it was not very common in phones when the Pixel 3 came out, and unfortunately the nRF Connect app is not trustworthy on the Coded PHY check.

My guess is that the phone is only scanning on the primary advertising channels (37, 38 and 39) and not the secondary ones where most of Coded PHY advertising takes place. If that's the case you should see one advertisement on your phone looking similar to this, where it only picks up parts of the advertisement (the ones on the primary channel).

Best regards,

Simon