Controlling 8 RGB LED strips - Beginner question

Other Hardware LEDs and Multiplexing
1

Hi all!

I'm just starting out with Arduino. I am hoping someone can tell me if I'm on the right track.

I'm attempting to create an automatic stair lighting system such as discussed here:

http://forum.arduino.cc/index.php?topic=192387.0

I will be working with 8 42"(approximately), common anode, RGB LED strips. Each will preferably be controlled independently in respect to color, brightness, and timing (on/off and perhaps fade), initialized by some kind of sensor. Likely a PIR.

I understand I will need 24 PWM channels. I have two Unos, and I don't mind obtaining a Mega 2560. I'm curious as to whether this is an appropriate product to make this work:

Would two of those and an Uno, or one of those and a Mega be an appropriate base for this project?

I'm hoping for some insight so I can start prototyping simple things and build up. Any links or comments would be appreciated.

Thanks!

2

Have you looked at the WS2812B?
http://www.ebay.com/itm/WS2811-WS2812-5050-RGB-LED-strip-Light-Waterproof-Individually-Addressable-DC5V-/111164910188
This is what I use.
Adafruit has a library.

Each pixel has built in PWM

3

See:

4

Thanks, Larry!

I've done a bunch of reading on these strips this morning. Seems like it is a solid way to go as long as I can figure out the code.

Considering that I want 8 individually addressed light sections, is the NeoPixel option easier since I'm new to coding? The wiring would be incredibly simple. I don't know enough about the code to say which would be more approachable.

It does appear that for the amount of LEDs I would use, I need to step up to a Mega for the additional SRAM.

5

You only need one pin to drive a neopixel strip.
Also needed is 0 volts an +5 volts.
Each pixel needs three bytes of RAM.
Color is very easy.
You can set any number of pixels on and set the intensity and Color of each.
Adafruit has a library:

6

See here for an example of floor lighting.

7

I think ShiftPWM would be another idea for your problem :wink: ( http://www.elcojacobs.com/shiftpwm/ )

For 8 RGB Ch. you would only need one Arduino, 3 shiftregisters ( 74HC595 ) and an AMP for each Ch. (N-Mosfet or NPN-Transistor or...)

An example for this: http://www.instructables.com/id/RainBoard-RGB-LED-Rainbow-Fader/ ( I've build it with 3 instead off 6 Registers on my breadboard and want to build 8 Panels (~ 150 LEDs/Panel) :D)