Introduction
In this post and video, we cover the newest development kit from Nordic Semiconductor: the nRF5340 LE Audio development kit, which was released in May 2022. You can learn more about the development kit here.
LE Audio represents the next generation of Bluetooth audio!
It requires support for an optional feature that was introduced in Bluetooth version 5.2 called LE Isochronous Channels (ISOC).
Some of the most prominent use cases include:
- Broadcast & audio sharing – location-based or personal
- Location-based: broadcasts available in certain locations such as Public Announcement (PA) systems in airports
- Personal-based: broadcasts set up by individuals for sharing audio with friends and family for example
- Standardization of Bluetooth audio for hearing aids and migrating from using the dated telecoil systems
- Multi-stream audio: support for multiple independent and synchronized audio streams to one or more devices
It also offers a much more flexible foundation and framework for developing audio applications and achieves lower power consumption, which is a really big deal especially for reducing the physical size of devices or for increased battery life.
Applications
Examples of applications:
- PA Announcements airports
- Movie theaters
- Conferences and venues - multi-language streams and allowing hearing-impaired attendees to listen directly to the audio source through their LE Audio compatible hearing aid
- Museums
- TV screens in gyms and public areas
- True Wireless Stereo (independent streams sent to independent earbuds). Even though it exists today in some products, LE Audio will standardize it and allow you to use devices from different manufacturers thanks to interoperability.
Along with the new LE Audio specs and profiles, a new more efficient audio codec named LC3 was introduced. It achieves higher quality audio at the same data rate or even slightly higher quality at lower data rates than SBC and is mandatory for all LE Audio devices.
Mode of Operation
LE Audio operates in two modes:
- Connected Isochronous Stream (CIS)
- Require a connection between the devices
- A limited number of connected devices
- Provides higher reliability
- More efficient utilization of the spectrum (retransmissions only occur based on feedback from the receivers)
- Support for bidirectional audio streams (earbud + mic)
- Broadcast Isochronous Streams
- An unlimited number of receivers can tune into the broadcast streams
- Inefficient use of the spectrum since the broadcaster may decide to include retransmissions even if the receiver is able to receive all the audio packets (due to the fact that no feedback from the receiver to the transmitter)
- Can be either open or secured
LE Audio is still in the very early stages, so you can expect that devices will continue to support Classic Audio and over time will transition to using LE Audio instead.
Nordic nRF5340 LE Audio Development Kit
Be sure to watch the video above to learn more about the newly released nRF5340 LE Audio development kit and a demo of both Broadcast Isochronous Streams (BIS) and Connected Isochronous Streams (CIS).
