What is your music source? Do you have access to the audio signal, or do you want a microphone?Audio signal is better, microphone picks up all noise, so if someone sneezes, it'll show.The one I made used Bluetooth audio from my phone, but works the same with a standard 3.5mm jack (using a splitter).I'm assuming you just want a pretty display. You're not using this to study sound frequencies. What I meant by averaging to get more bands is basically- between band 1 and 2 values, you could average them and insert an additional bar of your display at between 1 and 2. You'd get a smoother display.You have a lot to work through before even considering how to use the LEDs, but you should look at what Neopixels are capable of in terms of update speed. Maybe you don't see many Neopixel/WS2812B spectrum analyzer type projects because they're too slow. Adafruit has Dotstars which are faster. I've not hooked up to LEDs yet so I can't say. Maybe I'll do it some time this week for my own curiosity.
For what you want to do a Neopixel is fine and you will see zero difference if you use a dot star. A POV project involves moving the LEDs very rapidly, this is not what you are doing.I asked if you knew what you were doing in order to be able to pitch my answers better. So now I know it is to look cool rather than to actually measure things I can give you better advice.The equaliser is in effect seven second order band pass filters. Their is lots information in that last sentence that will mean nothing to you so try and look things up.The switched capacitor bit means that the filter's peak is dependant on the frequency of an oscillator, that in turn is set by the values of a capacitor and resistor that you put round the chip. If you have two chips and use slightly different values for each chip you shift the array of frequencies it outputs. Get it right and they slot between each other.Programming the Neopixels is easy and well within the capability of a Mega, in fact you could even do it with an ATtiny or Uno.
Yes that is what I said. However I also said that they are only second order filters so their is a bit more overlap. Get the data sheet of the device and look at the graph of the filters.I used two chips but used one for the left hand and the other for the right hand stereo channel. I used a raspberry Pi for this project, with an Arduino you just need to use 5V and you don't need the A/D converter. It is built into the Arduino. And you have the neopixel strips for a display.https://vimeo.com/167914646Then I also made this with the same hardwarehttps://vimeo.com/184643867Get the magazine articles on free download see the magazine's web site.
Should the power be coming from the arduino?
If you use a zig-zag connection* between the "bars" you have much less and shorter wiring.Every second "bar" will have the leds in reverse direction, but that can easily be hidden in software.* connect bar1 and bar2 on top, bar2 and bar3 on the bottom, ...
You don't need any PWM outputs to drive a NeoPixel strip.What R & C values are you looking to change?
So should I be using a Digital Pin to talk to the LED strips?
Yes, and a libiary to drive it. It is not the sort of thing you can program yourself.It is only the R between Pin 1 and 8 you need to consider if you want to make the bands interleave. All other components should be left as they are for a 14 band system. You are best using a 180K fixed resistor in series with a 47K pot wired as a variable resistor, for one chip and leave the other at 200K. Adjust the pot until you get the correct overlap between any two bands. All the others will fall into place.