How to use the Coded Phy?

[AGlass0fMilk]

Hi,

I am trying to write a range test app for the LE Coded Phy introduced in BLE 5.

I would like to test the maximum range and therefore want to use the 125kbps (8 symbols per bit) version of the Coded Phy.

I am currently trying to set the preferred phy to the Coded Phy using Gap::setPreferredPhys. There appears to be no API to set the version of the coded phy used (500kbps vs 125kbps). Is it possible to set this during advertising? Does the BLE spec limit which variant can be used during advertising?

I did notice there is a way to set the symbols per bit parameter once a connection is formed. I would like to avoid having to enter a connection -- advertising should be enough to test the range.

Further, I do not see a clear API that lets you set the primary advertising vs. secondary advertising phy.

There is no existing example to use the long range phy. EP may be persuaded to open-source our long-range test application once it's done if that would get us some help...

@pan- @paul-szczepanek-arm

[AGlass0fMilk]

Okay, so I found a way to adapt the BLE_PeriodicAdvertising example to scan and advertise on the Coded Phy. There are methods on scan parameters and advertising parameters to use the Coded Phy instead of the 1M phy. There is also a method to set the primary and secondary advertising phys.

I am now able to scan/advertise on the coded phy... however!

I still do not see an option (aside from during a connection, using the Gap API) to set the symbols-per-bit variant of the Coded Phy used during scanning/advertising. I assume during scanning the packet contains this information and so it can be automatically ascertained (?)

I did some step debugging to see what variant of the Coded Phy was being used by the Cordio stack. The variant used seems to default to "whatever the stack default is", which is thankfully the S8 (125kbps) variant of the coded phy. This is what I wanted at this point. But still, why is there no API to set this up outside of connections?

Maybe I'm missing a footnote in the BLE Spec that says the S2 coded phy can only be used for connections. I'm admittedly not fully up to speed on some of the BLE5 features like extended advertising and the new Coded Phy.

@pan- Is this a deficiency in the BLE API or am I missing something?