Complete noob to arduino

Well I wanted to install LEDs into my desk to give me some light to do homework by, and to just kind of look cool. I was planning to just do a simple circuit controlled by multiple batteries and an on off switch in there.

I saw arduino while looking for LED circuits and well what can I say, I am now hooked to the idea of using arduino to be able to control my LEDs. I just have a few questions.

I want to control 15+ LEDs which Arduino board should I get, also does arduino support RGB leds? And how would you guys suggest I get my project done. Again I am a complete noob at this so please don't flame me because this might seem like childs play to someone but to me it is rocket science to the 10th degree.

Also would I need any additional equipment if I wanted to control say 20+ LEDs? Or even with my current 15 leds?

have you looked at this area of the playground yet for projects or an idea? Lots of info there.

http://www.arduino.cc/playground/Main/InterfacingWithHardware#LED

You're going to need some external drivers. Do you have the specs for the LEDs?

Well I am not yet set on what LEDs I am going to use, I was planning on heading over to radioshack and picking some up there. Any suggestions for a good bright LED?

You need to be thinking about much current you need to light your LEDs. An Arduino can supply at most about 200mA across all its pins, so you'll need to be thinking about some external components in addition to your Arduino.

Alright, I understand the mA usage and such, but when you speak of external components what would those be. Sorry for being a noob.

You still haven't told us about your LEDs and how you want to wire them or what their specs are.

I havent purchased LEDs yet but I want either plain white LEDs or RGB LEDs, but I would like to hear any suggestions.

OK well I was interested in getting some RGB LED's and was wondering if these are any good?

http://cgi.ebay.com/20-x-5mm-DIFFUSED-RGB-LED-5000-mcd-Common-Anode-USA-/260570752541?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item3cab3a261d

Will they be bright enough to light up my desk so I can write/read etc. Also I did a little bit of research and I guess a good driver would be a TLC5947 as I saw another member was running quite a few LED's with it.

Also what Arduino should I buy, would the pro mini suffice for a simple LED strip basically or should I invest in something better to be able to have more options later on. And one last question I promise, can I use any wire, or is there a specific gauge of wire I should use for powering the LEDs or do they draw little power and the gauge wont matter at all.

That LED would not be in the illuminate your desk league. At least not a single LED. The TLC5940 is good but has a limited current capability. Power LEDs take 300mA and require heat sinks and constant current drivers. As discussed here:- http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1234273497 http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1258412419

So even if I had say 10-15 of them and made an LED strip it wouldn’t be bright enough to read by?

I am not looking to just hook one up and go I just want say 15 LEDs under my monitor and a few above my keyboard tray and maybe a couple more for decorative purposes. I chose RGB Leds because I get bored with one color too quickly.

Reading under any color other than white is a bit harsh, at least thats my personal opinion/taste.

I know that reading under any color except white is harsh, but I chose RGB because I can leave them on and change the color to set kind of a tone or mood if you will, don't get the wrong idea there :).

I would just like to have a very simple setup, an RGB Led strip of 15-20 LED's connected to a driver and then the arduino to give me control. I think I got that right, right? And would I be able to control each LED individually or would I have to control just the strip of 15-20 LEDs. I guess that would depend if I wired them in series or parallel?

I mean any help would be greatly appreciated. If anyone could help me out there might even be a reward or so to speak.

You need to make a decision early as to whether you want to control each LED individually, or as a colour channel. The first method requires (number_of_LEDs * 3) PWM channels, and the second requires 3 PWM channels.

Then you need to decide what sort of LEDs and how many you're going to use and look at their specs. Small LEDs may take 20mA each, large LEDs may take over ten times (and up) as much current, so how you supply and drive them has a big effect on your design, as does your budget.