New guy, no Arduino knowledge, need help with a crazy audio idea - Long post

Hello everyone. My name is Scott. I'm new one here. I actually only got on here for a couple of reasons.

First, I'm into car audio, and I'm always thinking outside the box trying to come up with my own DIY ideas. I love it. I enjoy researching. But there's always that overwhelming feeling the first time you come up with an idea that has to do with something you have absolutely ZERO knowledge about.

Second, I'm not afraid to learn something new. A lot of my smarts come with hands on, reading diagrams etc. It's so much easier for me to understand something when I see it on a diagram, along with an explanation on how it works. I'm pretty good with my hands and have a love for new skills.

So, all that being said this is what I'm currently working on. I'm not sure what I can do as far as pictures on here, but for now I'll just describe.

My current plans in my truck for car audio consist of a Samsung Galaxy Note Pro 12.1 tablet for a source unit. To get the best possible quality sound out of it, at this point, I'm using an Octava HDMI Amplifier/Distribution unit. Basically it takes an HDMI input, and amplifies it and sends it out by 4 different selections. 2 HDMI outputs, 1 Optical Toslinik Output, and Analog L & R output.

I'm using the Analog output, because I didn't want to go out and buy a processor. I decided to make my own Signal Distribution Unit. I'm going to have multiple amplifiers, which all have built in active crossovers on them, so no real need for a processor.

So I'm making my own signal distribution unit. I've used an empty amplifier case and cut it down to size. I'm using a balanced line driver to boost the signal from the Octava. I've tested this and it works well. I've purchased 4 Axxess AALC knobs. These are to control sections of the system. I knob for main volume, one for rear volume, one for center front sub, and one for rear subs. I have used an S.M.S.L. case for a headphone amplifier I was going to use for a separate project I had laying around. I've cut it down for the remote on the unit. Here's how I've done it thus far.

The knobs have been disassembled completely, and then I CA-Glued the knobs (potentiometers 50K) to the front of the boards, to give extra space to prevent touching the metal case. I then soldered wires from the board to the knobs, taking the place of them being soldered to the boards directly. Next I have an HDMI Breakout board. That will be my connection from the main unit, to the remote. Essentially, the signal is to come in to the main knob, then out to each knob and to the unit as the front signal. Then the second knob is for the rear adjustment, so output will be sent to the unit allowing me to adjust the volume of only the rear speakers. Third knob is to go out to the unit for the center front sub volume adjustment. Fourth knobs is for the rear subs volume controls. It's all very basic. The wires will go to the HDMI breakout board, and then through an HDMI cable, and into the main unit via another HDMI Breakout board. From there distributed to the rca jack outputs accordingly.

So far it's going well, however, I have much bigger ideas in mind. What I want to do is make it much better with an LCD screen for volume level monitoring, 1 knob (rotary encoder w/ push), 4 buttons to select which adjustment, and have it somehow be in a small footprint. Here is a list of what I'm after:

Single knob (rotary encoder – w/ push button) -
Short push – mute
Long push – power on/off
LCD screen -
Volume notification – 0-60 (?)
Selection adjustment notification
Single buttons for each adjustment selection -
Main volume
Rear volume
Center sub volume
Rear sub volume

How I want it to work -

"Volume" always on screen with numerical level monitor or a bar is fine too.

In general mode –
Main volume default – screen shows “Volume” with numerical level
Volume raised and lowered by knob
Screen shows all button names over the buttons
Push knob to mute – Screen flashes “MUTE” and output signal is muted
Push knob to unmute – “MUTE” goes away on screen and output signal is unmuted
Selection names above all buttons (Main, Rear, C.Sub, R.Sub)
All names above buttons indicates in Main/Default Volume mode.

Pushing a volume selection button –
Knob controls that selection level when button is pushed
Screen shows selected button name. i.e. rear volume would show “Rear” above button.
Others selections disappear from the screen, showing only the selection chosen.
10 second default back to main volume. – When a button is pushed (rear in this example), and not used for 10 seconds, the mode goes back to Main Volume as default.
All other button selections re appear on the screen.

On/Off - I want to be able to long push the knob and the unit turns off or on.

Small Remote Size –
Want the main pieces (encoder/knob, lcd screen, buttons) in a small case for up front mounting.
Want the brains of what makes it all work to be in the SDU Case in the back.
Small remote connection line between SDU Remote and SDU.

Here are a couple of pictures of what I'd like to make, or something similar. This is the remote for an Audison Bit One Processor. Some may be familiar with it, not sure. However, what I want is something similar, to the set up anyway. I don't care about the lights around buttons and knob etc. I'd also like for the volume to always be on, where the Audison is currently on the screen. Then the button names above each button.

Here is another picture with the volume on the screen. When you turn the volume knob it comes up on these, and then it goes away back to audison after a certain amount of time.

So that's basically what I'm after. I'm not sure if the Arduino is the way to go with this, or even how to go about making it all work. I'm hoping you all can help me with this. I don't have any clue on how to even get started with all of this. I'm just a guy with ideas.

Thanks all!

That looks feasible.

For the level controls you can use digital pots. I believe there are 3 kinds of digital pots - Parallel control, serial control and up/down control. Any of these can be controlled with the Arduino.

I'm not sure if you'll find a rotary encoder with a pushbutton.... I haven't looked... Sometimes these things are custom manufactured for a particular product/application.

...the first time you come up with an idea that has to do with something you have absolutely ZERO knowledge about.

I don't think you'll have any trouble with the hardware & wiring, but if you've never programmed before you've got some learning ahead of you.

Take it one step at a time... i.e. Learn how to read the state of a pushbutton, learn how to write to an LCD. Then when you're ready to put it all together, write a few lines of program code at a time, test-compiling and test-running as you go along.

These rotary encoders should all have a built in switch - check the datasheet before ordering.