DIY Open Source Bluetooth Headphones -- Episode 586

This was another interesting element14 presents project.

Up until now I've been using the likes of Denon or Radial Engineering Bluetooth receivers:  

https://www.denonpro.com/products/view/dn-200br

https://www.radialeng.com/product/bt-pro

to accommodate those pesky mobile device users... Starts to get expensive when you need to pair with multiple devices.

However, this open-source project looks like this could open up some alternatives and experimentation.

USB Audio 'Class Compliant' interfaces would be another interesting area to explore further. It would be great to have some 'problem-solving' adapters that can plug into a computer USB port without needing additional drivers and provide basic channel mixing / splitting type functionality along with basic level control and metering, ideally all within the limited USB power budget to avoid the need for yet another wall wart power supply.

that sounds indeed like a neat problem solving product! would be cool to elaborate on that.

oh thats is a whole different can of worms, but also a very interesting one.
I think with a USB-Host capable MCU one could act as an intermediary to pass on only the data not the USb communications form the PC unlike a switch/hub.
So the PC hosts an MCU via USB
the MCU hosts 2 USB devices
data from USb devices get pased on to the pc.
the PC only ever sees 1 device, so for it its the same device that just passes on different data.

the biggest challenge for that might be latency.

To keep it simple, the mono/stereo could perhaps just be a pair of slide switches.

I was concerned about the power consumption of the addressable LED VU meters but it makes for an interesting UX feature.

I think some dinky 20mA leds would be bright enough, no need for fancy neopixels IMO
since the device could fall under the EU- USB-C recommendetion the power limitations of USB 1.1. don't apply really, but having it all doable with 5V @500mA would of course be preferrable for max compability.

slide switches would be the simplest way for passive routing ,but beeing able to mix them lets say via digital pot would be cool...

Yes, that was intended as a separate project idea.  

( The Inogenie devices do the webcam switching:
https://inogeni.com/product/share2u/  )

Seems the intended use is dunymic composition of additional sources into an hdmi feed, that is passed on downstream.
yeah a simpler solution for just the mentioned usecase seems to fit aniche here!

They do a 4:1 switcher 2xUSB/2xHDMI as well:

https://inogeni.com/product/cam300/

Originally, I was thinking of passive routing with the switches but then I was thinking of GPIO inputs so that their function could be defined in software depending on an individual's use case making it more flexible.

They could also be push buttons though that act as a simple mode selector that uses the LED VU bar position to show what mode you are in and then the rotary selector does inc/dec push to set.

5V at 500mA would be ideal as there is a lot of kit out there that isn't USB-C yet. It could use a second USB port though to bring it up to 1000mA, without reaching for a wall-wart PSU.  

In a lot of cases, the LEDs don't need to be on for the duration. They would mainly be used for configuration purposes, so a small battery could be used to provide the additional power demand for LEDs or even a small OLED display. However that adds to the design.

oh i just saw how expensive these devices are, well a simple solution just focused on the task would surely be abit more accessibly priced.

the internal battery for the higher demands and charging while its not in use is such a cool idea, of course it adds complexity but would also make the device better for payortable applications like podcasting on site.

That's one of the problem areas, most people can probably pull together a few low-cost USB devices, but when it comes to using several together, it can quickly become an overly complicated and expensive business.

That's one of the problem areas, most people can probably pull together a few low-cost USB devices, but when it comes to using several together, it can quickly become an overly complicated and expensive business.

also making them all play nicely togethers and have no wonky conenctions is a cluttered desk in itself