LE Audio on nrf52840

RE: LE Audio on nrf52840

ken_he — Sun, 17 Mar 2024 12:06:56 GMT

SwRa

How much current can the nRF5340 consume in CIS and BIS modes under LE AUDIO?

RE: LE Audio on nrf52840

daoms — Wed, 20 Jul 2022 07:09:46 GMT

Hi SwRa,

Thanks for your clarification. I think It's helpful for those who are new to 5340 Audio DK.

RE: LE Audio on nrf52840

SwRa — Tue, 19 Jul 2022 13:48:56 GMT

Hello,

I fully understand the confusion here, as there are indeed two instances of 'codec' appearing in relation to the LE Audio specification and the nRF5340 audio DK. The first, most prominent use of 'Codec' usually refers to the software codec that encodes/decodes the audio stream that is to be transmitted or has been received, most commonly the mandatory LC3 codec. You are correct that this codec is completely software based.

The second possible use of 'codec' is what we usually differentiate by saying 'hardware codec', which in the nRF5340 Audio DK case refers to the CS47L63. The CS47L63 is a high performance low-power audio DSP: https://www.cirrus.com/products/cs47l63/

The CS47L63 is specifically made and optimized for the earbud use-case.

As you can see from its datasheet it also has the possibility to do DSP on top of the ADC/DAC functionality, but the nrf5340_audio reference application only uses it as a ADC/DAC currently

Also, it is possible to switch the CS47L63 with any other ADC/DAC..

Best Regards,

Swathy

RE: LE Audio on nrf52840

daoms — Mon, 18 Jul 2022 01:38:04 GMT

It seems that things are still not very clear. For 5340 audio DK,

1.who is doing the LC3 coding-decoding process, or who is running the LC3 code, I suppose it is the 5340 itself, right?

2.the DSP CS47L63 on board is acting only as ADC and DAC. It just converts the I2S signal(PCM format) to analog output to headphone? It doesn't do any compression to audio data, nothing to do with LC3. You can use any other ADC/DAC instead, not concerning about the power consumption or cost etc. Right?

Appreciate any explanation.

Tks,

RE: LE Audio on nrf52840

SwRa — Mon, 04 Jul 2022 14:20:32 GMT

Hi Jash,

Codec can be hardware based or software based.. Codec takes data in one form, encodes (ADC) it into another form and decodes (DAC) it at the output end.. The CS47L63 is a high performance low-power audio DSP: https://www.cirrus.com/products/cs47l63/ It takes in the analog audio audio signal, encodes, process and decodes it. The CS47L63’s high-performance DAC and differential output driver are optimized for direct connection to an external headphone load. Please go through the data sheet of CS47L63 to get more understanding..

Nordic semiconductors have two DK based on nrf5340: The nrf5340 DK and nRF5340 Audio DK.. The Audio DK is the one suitable for the audio application and has the CS47L63 chip on it..

Regards,

Swathy

RE: LE Audio on nrf52840

Jash — Sat, 02 Jul 2022 05:56:11 GMT

Hello Swathy,

I have a doubt from codec point of view. Is CS47L63 a codec chip or DSP chip. My image for codec is that it is completely handled from the software side. Does it require hardware?

Any help will be appreciated :)

RE: LE Audio on nrf52840

SwRa — Fri, 01 Jul 2022 12:37:55 GMT

Hi Jash,

We have an example for the LE audio application in which a brief description on all of the concepts and steps involved are explained.. This sample can be used as a base to start developing.. Kindly take a look at this documentation: https://github.com/nrfconnect/sdk-nrf/blob/main/applications/nrf5340_audio/README.rst

The nRF5340 Audio DK has the codec chip CS47L63 and by default uses LC3 codec.. you can also switch to use SBC codec by changing a few configurations..

Regards,

Swathy

RE: LE Audio on nrf52840

Jash — Fri, 01 Jul 2022 07:02:20 GMT

Hello Swathy,

I just checked the nrf connect SDK for nrf5340. I want to develop an audio streaming hearing aid. I have noticed the special feature section in the datasheet, wherein it is mentioned DSP instruction. Can you provide me with any information on how the data from smartphone to 5240 SOC will be transferred via BLE using SBC codec and any support regarding communicating with DSP.

Looking forward to hear from you as well as anyone who can help :)

RE: LE Audio on nrf52840

SwRa — Thu, 30 Jun 2022 14:25:32 GMT

Hi Jash,

It is possible to use nrf52840 to develop LE Audio applications.. but we recommend and provide official support to LE audio application development based on nrf5340 (nrf5340 Audio DK). You can find the details here: https://www.nordicsemi.com/Products/Bluetooth-LE-Audio

The nrf5340 Audio DK is the recommended platform for Bluetooth LE Audio products: https://www.nordicsemi.com/Products/Development-hardware/nRF5340-Audio-DK

The latest nRF Connect SDK v2.0.0 supports Bluetooth LE audio and have examples for the same: https://www.nordicsemi.com/Products/Bluetooth-LE-Audio/Development-Software?lang=en#infotabs

nrf5340 Audio application: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/applications/nrf5340_audio/README.html

Best Regards,

Swathy