I have a project that requires 900 12mm Diffused RGB LED Pixel WS2811 12V Addressable modules and I am not sure what Arduino I should use. It will be for dock lights so for most of the year it will be standard lighting and a little animated on holidays.
Any Arduino will probably do what you need.
The only real question is how many patterns you may want to change / store in memory.
Once you get to thinking about large strings or arrays of LEDs, you need to think about power supply to the LEDs - current, and signal integrity.
The power supply demand is, if you want full brightness, around 900x60 ma. = 54 amps. But bear in mind that the power supply leads running the length of a strand of neopixels are much too delicate to be carrying that power supply load. You'd best find a way to break up your LED's into, say, 9 strands of 100.
Also, as I understand it, the data rate for loading these LED's is 800 Kbits/sec. and with 24 bits per pixel, you have a little short of 3 ms. for each data load. That sounds feasible, but the arduino may have housekeeping chores going on that must occur more frequently than that. I can't claim any expertise as to that, but it could interfere with trying to run all of these from one arduino. This may require that you use more than one arduino, or perhaps something with a higher clock rate.
Thank you for the pointers, I did some more research and as suggested, breaking them into manageable groups that I can insert power but I am not sure if the length of the run is going to be too much for an arduino to handle.
I am installing lights on a dock that is about 500 feet long and has 84 dock pilings that I am going to install lights on. Each piling will have 11 dumb RBG nodes. I plan to split the string into 10 groups, with a 27-Channel DMX RGB Controller (9 RGB groups) and a 60W 12V Waterproof Power Supply connected to each.
Could I use an arduino to run this?