Register access nRF5340

[RomainB]

I'm working on the nRF5340 Audio DK board from the nrf5340_audio example project in sdk 2.3 and I'd like to test the different Bluetooth data rates of the nRF5340 SoC present on this board.
In the documentation, I was able to locate a register, MODE 0x510, of the Radio device, 0X41008000, grouping together the different BLE data rates: 2 Mbps, 1 Mbps, 500 kbps, 125 kbps.
However, I don't know how I can access it to modify this value and set the bit rate of my choice.
Does anyone know how to do this please?

Sincerely

[Karl Ylvisaker]

Hello,

However, I don't know how I can access it to modify this value and set the bit rate of my choice.
Does anyone know how to do this please?

If you do any register manipulation directly in combination with using one of our drivers then you may place the driver in an invalid state, which in turn could break its functionality. Please always just use the intended driver/module APIs directly, instead of register manipulation.

Could you elaborate which part of your application you would like to change the PHY for?

Best regards,
Karl

[RomainB]

Thank you for your reply.

I would like to change the bit rate to test the range of Bluetooth communication. So I would like to use the 2Mbps, 1Mbps, 500kbps and 125kbps data rate to test the different ranges.
Is it possible to change it or not ?

Best regards

[Karl Ylvisaker]

Hello,

RomainB said:

Thank you for your reply.

No problem at all, I am happy to help!

RomainB said:

I would like to change the bit rate to test the range of Bluetooth communication. So I would like to use the 2Mbps, 1Mbps, 500kbps and 125kbps data rate to test the different ranges.
Is it possible to change it or not ?

It is possible, yes, but it would depend on the use-case of your application. For instance, our LE Audio controller does not have support for Coded PHY currently, and so that is not an option when combining this with LE Audio.
In general, your power consumption and audio quality will also be worse if you use 1 M instead of 2 M PHY, which is why I ask if you could elaborate on your use-case and intentions so that I may provide you with the best advice.

Also, there are other configurations (based on your use-case) that you could change as well to increase range, such as TX Power and connection/advertising parameters.

Best regards,
Karl

[RomainB]

Hello,

Sorry for the delay in replying.
I would like to thank you once again for your clarifications.

In my case, I simply want to know and define the limits of use of the nRF5340 Audio DK card concerning Bluetooth LE Audio communication.
I would welcome any advice on how to improve or not communication in terms of range, power consumption or audio quality.

Best regards,
Romain

[Karl Ylvisaker]

Hello Romain,

RomainB said:

Sorry for the delay in replying.
I would like to thank you once again for your clarifications.

No problem at all - we will continue this whenever you get a chance :) 

RomainB said:

In my case, I simply want to know and define the limits of use of the nRF5340 Audio DK card concerning Bluetooth LE Audio communication.
I would welcome any advice on how to improve or not communication in terms of range, power consumption or audio quality.

This is a very broad question since the LE Audio specification is made to be very flexible so that you may configure it to fit your application perfectly. It would therefore be easier if you could elaborate on your intended use-case so that I may better advise you on the optimizations you could use.

For instance, to increase range we could increase the TX power along with the connection and stream parameters (shorter intervals, additional retransmissions), but this will come at the cost of increased power consumption. If a very large operating range is paramount to the application then you should also consider adding a Front End Module (FEM) to your hardware to increase the range to either +10 dBM (EU) or +20 dBm (US), but this will further increase power consumption.
If low power consumption is more important than range and quality we could make other optimizations to target this as well, but it would be easier to discuss this with a specific use-case in mind.

Best regards,
Karl

[RomainB]

Hello,

For the moment, I don't have any specific plans for an application. It was more a question of studying the card to better understand how it works and whether it could be useful in future projects.
In any case, I'd like to thank you for your answers, which have given me some ideas for future research.

Best regards,
Romain

[Karl Ylvisaker]

Hello Romain,

Aha, I understand - thank you for clarifying.
If you wish to read more in-depth on the LE Audio specification (but not quite want to look at the specification) then I would highly recommend the Introduction to LE Audio book by Nick Hunn - this is also a great book to look up specific configurations or questions on your own, if you should have any.

You can of course also always open another ticket here on DevZone to ask us any question you might have - we're happy to help! :) 

Best regards,
Karl