So with this project I’m attempting to make my old analog 5.1 surround sound system a little more digital with the use of a Raspberry Pi Zero W.
Rather than having cables going all over the place, connect a RasPi0W to the system and then transmit a signal via Bluetooth or WiFi to it and hopefully it can decode the audio into the surround system. As it is I have a HDMI audio splitter that can take a HDMI video signal and copy the audio signal, decode it into 5.1/7.1 surround or what ever the original audio signal is. I also have a Dolby Virtual encoder too that can take a two channel signal and create a virtual 5.1 surround signal with what ever magic it uses (and it does seem to work quite well with previous uses).
So at the moment I’m installing software/firmware onto the RasPi0W via this installation process https://sound.balenalabs.io/
so it will be interesting to see how this pans out!!
Well… that failed!!
It just didn’t want to happen? even after a day of trying.
Take 2.
So back to the drawing board, and reformat the sdcard and try something else. I did remember seeing something a couple of years ago that kinda fitted my idea, but I remember it didn’t work, but then again I now have 2 years of messing with Pi’s and coding so I thought I’d give it another go.. and…Success.
I went with this version https://github.com/nicokaiser/rpi-audio-receiver and this time I was able to install the parts I needed and omit the ones I don’t. so I’m currently testing it as I’m typing this by listening to music from my streaming server through my phone with my headphones connected (wire) to the Raspberry Pi Zero W via an audio USB dongle. Now with the Raspberry Pi being headless (without a screen) and without a user interface (desktop) it can only be controlled via command line.
So even the little things like volume have to be controlled via command line. But it’s not that hard to do. Especially when you know how.
So all that is left to do is incorporate it into my 5.1 surround system somehow, Power shouldn’t be too much of a problem as both the HDMI audio splitter and the Dolby virtual surround both require 5V , and the raspberry Pi Zero only uses a few hundred mAh, I should be able to take the power from somewhere without causing too much of a power loss.
I’ll post up photos if I can get it done, I also have the option to add a Vu meter if required, even if its two green and one red LED for clipping should be enough!
Well it worked, sort of!
So after testing which worked fine, I incorporated the system together, but there was too much interference coming through the audio, so it was back to the drawing board, as it was just not workable.
Third attempt.
So after that I remembered I had an old Bluetooth speaker that didn’t work, so I removed the module from that and with a quick online search I found the schematics for the pin-outs. So with that wired it up, and again testing worked fine.
I even surprised myself on how quick I got it working, and how well it worked, but when I added it to the system it seemed to short out the power supply? and for some reason just stopped working… OOPS!!!
Even though its something I’ll keep in mind for the next time I have to incorporate Bluetooth audio into anything.
Finally…
All was not lost though, I knew if all else failed I had an old pair of Bluetooth headphones that stopped charging, even though everything else worked. So a quick dismantle and rewire,and BINGO.. it works, actually better than expected.
