LED Strobe Light

[nes999]

I want to make a box with a few different colored LEDs for a special needs family member. This is my first time dealing with small electronics.  I am having a total of 32 LEDs. The most on at one time is 16. However there will be rapid flashing between colors.

 Do I plan for enough power for all 32 LEDs or for the max of 16 that will be on at one time?

If it matters I am using an arduino to control the flash patterns.

[ebclr]

In the worst case scenario 500 ma will be enought, but probably you will be in 200 ma range

[ajb]

There's no need to design for conditions your device is never expected to see.  Whether your expected conditions are accurate to the intended usage scenarios is another question, though.  "Rapid flashing" isn't a concern as long as one color is turned off before the other color is turned off, but even a brief period of both being on may be able to be covered by bulk capacitance. 

What sort of LEDs are we talking about here? 

[BrianHG]

For my recent flashing led project, I used this cheap SOT-23 mosfet: BSS806N H6327 which I drove right from my PIC's IO with a gate drive of 2.5v or above, and had a series resistor to the power LED I was using.
Though in my case, I was sinking a 2 amp pulse to strobe illuminate a room, you will only need to use a fraction of that with normal LEDs.

[nes999]

There's no need to design for conditions your device is never expected to see.  Whether your expected conditions are accurate to the intended usage scenarios is another question, though.  "Rapid flashing" isn't a concern as long as one color is turned off before the other color is turned off, but even a brief period of both being on may be able to be covered by bulk capacitance. 

What sort of LEDs are we talking about here?

Attached below is the full data sheet for the ones I bought.

I know those are really bright, However what they are using now are construction strobes and I'm afraid if they want from that level brightness to a dimmer LED he will not use it. I figured I could make this, and if it works try making a dimmer one also.

I'm really glad to see that I only have to have the battery sized for what's on at the moment. That means I only need to supply it with a 12v battery source, and of course appropriate resistors.

http://cloud.tapatalk.com/s/587275821a089/YSL-R531Y2C-A13.pdf