Silman:
i hear a lot of talk bout the MSGEQ7 chip but i have no idea how it is used to control color/brightness.
The MSGEQ7 doesn't control color/brightness, it analyses sound data and gives you the results. YOU are the one who writes the software function to map the output of the MSGEQ7 to the LEDs.
Silman:
Secondly if i did end up buying the digitally addressable ones i will still want to controlo color and brightness with both a remote and sound input, but i will also want to be able to to switch into modes. Such as a visualizer mode where it picks up sound and "pushes" the LEDs across the strip according to the sound, or a rainbow chase mode where it circles through the colors except all offset a little. I assume this is just a little more coding to do and won't be much more complex than setting up IR control for the analog ones.
That's more software. Once the hardware is set up you can really do whatever you like (and change it as many times as you want...)
Silman:
The difference though, is that the analog ones only have 4 input (one for each color and then ground) but the digital ones have data in, clock in, power, and ground. Clearly if i chose to do analog it will require a lot more chips in order to control brightness and color as i will need to vary the voltage going into each of the three color controls (I am assuming).
You need three MOSFETs.
Silman:
If i chose to buy the digitally addressable ones then I still need to learn how to make the arduino receive the IR remote control data, but instead i will be trying to figure out how to control the color, brightness of the digitally addressable ones, which i feel is much easier. If i am not mistaken (and please correct me if i am wrong) the digitally addressable ones can have color and brightness set via just the digital signal sent to it? I will need to learn the protocol for sending digital signals to each individual LED, is there a resource I can go to learn more about this in depth?
It's just RGB color, 8 bits of each for each LED.
Silman:
These are currently the ones i am looking at, but I can't help but wonder if there is any cheaper ones? 15 meters is a lot and I don't want to be breaking the bank just to get individually addressable LEDs on my walls!
Do you need 60 LEDs/m? Strips with 30 LEDs are much cheaper.
Silman:
Lastly i am curious about powering such a long strip of LEDs. I read on adafruit that to avoid "brown out" you need to power the LEDs every meter, does that imply i need a separate power supply each meter? Or is there a way to wire it such that you apply "fresh" power from the power supply each meter?
Yes, 15m at 60 RGB LEDs/m is 2700 LEDs so you need a LOT of amps.
For 15m of those strips you'll need a 60 amp power supply (seriously!).
You only need one power supply. You can run a really thick power cable alongside the strip and put in little 'jumper' wires from that across to the LED strip. Every meter sounds a bit much to me on a long strip (don't believe everything you read in forums), every two meters should be fine.
Silman:
Oh two last questions! Since this is my first real arduino project and i intend to keep it forever, where do i go to learn about burning the design to a "permanent" chip? Or do i have to keep my arduino attached to the LED strip forever if i want to keep these forever?Secondly, What is a good material to diffuse the LED light so i get an even spread instead of just a bunch of dots of light? I need it to be easy to cut and apply to walls and it needs to house the LEDS.
An Arduino Uno with wires poked into the header strips isn't ideal for permanent installations. For that I use Arduino Pro Minis - much cheaper/smaller and you can solder wires directly to the board.