Android nRF Connect - proper indication of Coded PHY support

[Lukáš]

Hi, we just found out a bug in nRF Connect for Android indicates that the phone Sony Xperia L4 supports Coded PHY. Unfortunately, when we try to run Bluetooth: Central Heart Rate Monitor with Coded PHY sample, the advertisements on this phone cannot be seen. When we use other phones (e.g. Samsung Galaxy S20 or OnePlus 8T), they can both show advertisements in nRF Connect from that sample. What could be the possible issue? I found this ticket on DevZone but I don't know if it is relevant.

This is a screenshot from Sony Xperia L4 indicating that Coded PHY is supported:

 

Advertising extensions work, but on 1M LE PHY, not on Coded one.

[Hung Bui]

Hi Lukas, 

We have reports on other phones having the same problem. The controller might not support scanning in Coded PHY. For example Pixel 4, there is a discussion here: https://github.com/NordicSemiconductor/Android-BLE-Library/issues/166

So the conclusion is that the phone marked isLeCodedPhySupported but it doesn't support connection establishing via coded PHY. But it may support switching from 1Mbps to Coded PHY. So the connection has to be established normally, and then you switch to Coded PHY after that. 

[Lukáš]

Hi,

Well, then this should be either specified or fixed with some test in the nRF Connect app. Now the app says Long Range Coded PHY supported, but it is only partially true. Actually, it might put people in the same situation as us that they will buy a phone based on this info and then they got disappointed that it won't work.

Almost a year ago, the maintainer of Android BLE Library wrote:

> I'm working on a test feature in nRF Connect for Android that will let us create such list, but this is still month before releasing.

Could you please ask him, when this one will get released?

[Hung Bui]

Hi Lukas, 

Please note that the app just printout the OS's device information that it can read. It's not a bug on the nRF Connect app. In addition a device can claim that it support CODED PHY if it allow switching from 1Mbps to CODED PHY in connection. It's not obligated to support scanning/connection establishing using CODED PHY to claim that it support CODED PHY.

I will check with the developer if he find a way to detect this.  He will be back from parental leave by 15th Jan. 

[Gary M.]

Hi Hung Bui,

I am using Realme 3 Pro (Model: RMX1851). Through nRF Connect Apps I can see my phone support all the LE features, I can scan Coded PHY advertising packet too. However I cannot establish connection with my peripheral (nrf52840) when it is advertising in Coded PHY, I can only scan them. I did look into the link to the Pixel 4 discussion, the problem is similar but not quite the same as my phone can scan the Coded PHY advertising. 

I just want to know if there is known issues like phone that support advertising and scanning in Coded PHY but cannot establish connection with Coded PHY? It has no problem connecting to the peripheral in Extended 1M PHY.

[Hung Bui]

Hi Gary, 

Could you tell how you advertise with Coded PHY ? Did you use extended advertising ? 
Have you tried to establish the connection in 1M PHY and then request to switch to CODED PHY ? 
We currently don't have a full overview of which phones support CODED PHY.