I need to feed two headphones from one audio source. In the past, I've done this with one of the many Bluetooth transmitters that support two headphones. I assume the transmitter did this by simply opening two Bluetooth connections, perhaps by using two Bluetooth chips.
My transmitter has recently broken, so it's time to buy another. I've seen various opinions on whether Bluetooth 5 has a new protocol feature that supports two headphones. If true, I'll look at transmitters supporting that feature. Presumably, since the protocol would be affected, I would also need new compatible headphones.
If anyone has definitive information on Bluetooth 5 support for two headphones, I'd like to see it. And, it would be useful it you can reference the specific Bluetooth 5 profile that defines the feature, or perhaps the section of the Bluetooth spec.
Thanks,
Ron
They say that Bluetooth Hearing Aid Profile will support multi-user HQ audio and audio broadcast, but it is not adopted yet.
Related
This article describes my main annoyance with Bluetooth: They are perfectly fine for listening to music with AptX (and the new LC3).
But till now, it was impossible to replace a "traditional" headset (whether wired or with a proprietary USB dongle) with a bluetooth headset because as soon as you activate the mic, it switches to the HSP/HFP profiles, which use low bitrate, bad codec mono audio, and quality drops to terrible.
That means I can't drop into discord and watch a movie. (Well I can, but audio will suck)
Has there been any progress on this with Bluetooth 5.x / Bluetooth LE Audio? Have the HSP/HFP profiles been updated to also use LC3, or are there new bi-directional profiles?
The LE audio website hilariously only focuses on hearing aids. The information content regarding microphone quality is damn near 0 (and the spec isn't out yet), but in one side remark of a talk there was a slight hint that microphone quality could be better.
This impression is aided by the new architecture allowing high quality audio and some microphone transmission simultaneously. The use case presented was talking to a voice assistant while listening to music, but one can hope it'll also apply to acceptable quality voice calls.
However, as for some reason regarding the topic, none of the so far available press releases by Qualcomm or Nordic Semiconductor are mentioning this as a feature.
there seems to be an extension called FastStream, which supports a voice backchannel in A2DP.
In that reddit post is a non authorative, non-exhaustive list of supported features per device. None of my BT headphones support FastStream, so I can not test that.
I want to develop the application to input the voice from the microphone of the Bluetooth headset and to output into the Bluetooth speaker.
I think that use of HFP to input and A2DP to output.
The two profile can be used at the same time?
I'm interested in this as well. From what I can find, it sounds possible but I've yet to see many hardware vendors specifically market it as a feature.
Creative recently released their BT-W2 bluetooth dongle that supports what they're calling a "voice-back channel". Might be similar to what we're talking about but it's hard to find tech specs that confirm it.
Below is a link to some documentation I found on the Bluetooth SIG website that appears to support the fact that it's possible. Maybe it'll help you:
https://www.bluetooth.org/docman/handlers/DownloadDoc.ashx?doc_id=296662
I am trying to identify which android phones support Bluetooth Low Energy and I am a bit confused on whether or not a device with BTv4.0+ is BLE compatible.
To be more precise, I am looking at the device Samsung Galaxy J5. According to http://www.gsmarena.com/samsung_galaxy_j5-7184.php, the bluetooth version is 4.1 but it doesn't mention anything about BLE.
According to the bluetooth specification:
"Bluetooth Low Energy (LE) (also called Bluetooth Smart or Version 4.0+ of the Bluetooth specification) is the power- and application-friendly version of Bluetooth that was built for the Internet of Things (IoT).". According to this I would presume that 4.0+ is BLE.
However if you see the specs of Samsung Galaxy S6 (http://www.gsmarena.com/samsung_galaxy_s6-6849.php) it mentions that it supports both BTv4.1 and BLE. It therefore distinguishes the two BT specifications.
Any information would be very helpful
Edit
Additional reference information for interested parties:
from bluetooth.org: Two flavors of Bluetooth The two most prevalent implementations of the specification are Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR), which was adopted as version 2.0/2.1, and Bluetooth with low energy (LE), which was adopted as version 4.0/4.1/4.2. Each implementation has different use cases and each implementation uses a different chipset to meet essential hardware requirements. Dual-mode chipsets are also available for applications that include both use cases. - See more at: https://www.bluetooth.com/specifications/bluetooth-core-specification#sthash.7X7IrtWy.dpuf
Instead of relying on gsmarena with unreliable information, you can refer to Bluetooth SIG's official information.
Based on this Bluetooth SIG's announcement and this one, BLE is a core specification of Bluetooth 4.0. Bluetooth 4.1 and 4.2 also adopt this core specification.
However, all this still depends on whether the manufacturers implement the firmware. To keep track of all this, Bluetooth SIG maintains a list of devices currently supporting any profile (for example GATT).
This crossed my mind myself as I saw it as a pointless advancement until I saw the low energy bLE (bluetooth low energy) side of it. In my pastime I tinker with various electronics and with various BLE 4.x modules and their pro's and cons are HUGE.
All in all, BLE is better as Bluetooth pretty much is battery drain on the most robust of phones.
I found a nice little writeup (pretty simple yet comprehensive) here: http://www.argenox.com/bluetooth-low-energy-ble-v4-0-development/library/a-guide-to-selecting-a-bluetooth-chipset/
Do cut my answer short, as the bag you linked shows it as being "NFC" compatible, then yet, it's BLE 4.x. (That's Near Field Communication i.e. similar to your your contactless bank card). The v4.1, A2DP which you mention is how one "audio device talks to another" via bluetooth. (dvanced Audio Distribution Profile).
If you're really bored, there's a long list of other profiles (other than A2D):
https://en.wikipedia.org/wiki/List_of_Bluetooth_profiles
Hope this helps!
Happy bluetoothing!
I am trying to get my hands dirty on understanding Bluetooth (BT) for building a BT based speaker. When i read through Google on selecting the device, i came across CSR, TI and few more of them. After some research and talking to ppl, they suggested to go with TI (CC256x series). Few questions i have here are:
Can the same TI chip be used as Speaker, BT headset?
Can both SPP profiles and audio profiles co-exist together?
I am not sure as a application developer, i should know about BT firmware but wanted to get some insight on how BT works. Any good books?
Sorry for asking basic question here
-Prashanth
Yes! Audio transfer requires a high data rate which means you have to use a chip that supports bluetooth classic and not low energy (ble). The CC256x offers both a bluetooth classic and a dual bluetooth (classic + low energy) version, both will work.
Yes! SPP and audio profiles are implemented on different streams and it is normal for them to co-exist.
Good books on bluetooth classic are hard to come by, one of the best places to start is the Apple developer documentation (linked down below). The developer area of bluetooth.org is also a good place to start.
https://developer.apple.com/library/mac/documentation/DeviceDrivers/Conceptual/Bluetooth/BT_Intro/BT_Intro.html
https://developer.bluetooth.org/
I understand that Bluetooth profiles consist of other profiles and protocols. What I don't understand is exactly how Bluetooth devices interact with each other. For example, if you take any accessory that implements the A2DP profile and connect it to the iPad then the iPad will stream all audio output to it. This makes me believe that a profile is nothing more than a modular component in a well-defined eco-system. For instance, a web-browser can use any one of your choice of search-engines in the toolbar; would I be correct in saying that the iPad is the equivalent of the browser and the A2DP accessory is the equivalent of the search-engine? Would I also be correct in saying that the use of A2DP is entirely up to the device it's paired with? That is, Apple could have instead chosen (albeit unwisely) to make the iPad output only key-clicks and ring-tones to it, correct? So there's nothing inherent in the A2DP profile that says "All devices using the A2DP profile MUST output all audio to it" right?
I'm not 100% familiar with Bluetooth as a whole. I've been spending some time drafting a profile for BT Low-Energy, so someone might be able to provide insight on standard Bluetooth with a little more detail.
But, from what I understand, the profiles are essentially a large map of connected references. So the A2DP profile will have a list of attributes, or rather, a list of HEX values which point to attributes within the larger profile. These attribute are typically universally available to all profiles, but only implemented by the profile where they are needed. These attributes define some piece of information that is going to be transmitted. This profile needs to be on both device to communicate, because this allows to Bluetooth transmissions to be smaller by only referencing a commonly known definition of the data it is transmitting (rather than defining what the data is in every transmission like some communication types).
So for A2DP, the transmission might be something very simple like '0x1351458 0', which tails the device that whatever that profile attribute is, it's value is 0. So that attribute might be the "play" attribute, so setting to 0 might stop the music.
Again, this is how I understand Bluetooth profiles from the Low-Energy standpoint which tends to be more a transmission of state than actual data, so it might differ a bit with regular Bluetooth.
Bluetooth profiles are specifications of bluetooth protocols that are implemented on the host side in bluetooth protocol stack.
Following link by bluetooth.org will provide basics about bluetooth profiles
https://developer.bluetooth.org/TechnologyOverview/Pages/Profiles.aspx
Bluetooth Profiles are set of standard interoperable guidelines defined by bluetooth.org, to ensure interoperability between different bluetooth devices.
Bluetooth devices claiming to support bluetooth profiles, should get Bluetooth Qualification Board[BQB] certified for interoperability.
You can buy any device supporting A2DP and test with any tablet/computers[which has bluetooth A2DP profile supported].
A2DP is not specific to iPad. It is a generic profile that stands for Advanced Audio Distribution Profile for exchanging Audio between two bluetooth devices.