RGB LED Questions

Okay, so I'm a little confused at this whole thing. I want common anode LEDs correct? This lets me pulse the +V? Why aren't transistors usable for PWM with LEDs?

Also, as I'm just learning about transistors, they seem like the perfect solution for everything. Can a PWM signal ever be used to control a transistor? I saw something here that MOSFETS might be possible to control as they have faster response times.

I want to make a color changer that has three potentiometers where a user can adjust the pot and change the colors. I would run strings of 12v LEDs (so the driver needs to be able to do 12v).

As there's a bit of information out there with the tlc5940, (TLC5940NT Texas Instruments | Mouser Europe)
is this the safest one to get?

I'm using the TLC5940 and recommend it. Between the chip and the Arduino library available, a lot of the difficult work is already done. How many LEDs do you want to string together?

This is my prototype: http://www.cmiyc.com/blog/2009/03/25/row-your-boat-part-1/

Still working out the PCB design so I (easily) extend the number of 5940s and LEDs.

@ Interesting: You can use transistors with PWM. It's used to control motor speed without reducing torque by just passing less current through. But for LED control for more than say two; the TLC5940 is very recommended. I've got some free samples direct from TI and they are great! Hooked one up with a breadboard and the TLC5940 Library in no time.

Haven't ventured into daisy chaining because I can't afford to buy a bigger breadboard or any more jumper wires.

@ CMiYC: I like the patters you've created. I'm trying to develop an RGB 8x16 LED matrix with three TLC's and a darlington array.

But I'm having trouble generating cool patterns without directly coding then into memory and working out all the colours by hand!

Got any code to show?

/me