FastSPI_LED2 driving an @Adafruit_Industries “Neopixel” (WS2811) Arduino shield. Thank $deity for the master brightness control in the library API… this thing is BRIGHT, with forty pixels all close together, all pointing exactly the same direction.
Hope you were wearing some very dark sunglasses!
I had the master brightness turned all the way down to 64, and I was wearing welding goggles and a lead body shield that I borrowed from my dentist’s x-ray technician. Even so, I think I have tan lines in the shape of the pixel array.
LOL! That just tells me you’re whiter than milk. 
I use my forearm to calibrate the white point on my monitor.
Do you know if those are regular 5050 RGBs, or some other specific type that’s much brighter?
I think they’re 5050s. But 5x8 of them with roughly 1cm spacing, and all pointing exactly the same direction is bright.
The shield can draw power from USB or from an external 5v source.
Adafruit’s page is here:
So at full dutycycle, that thing would pull 2.4A … USB spec says 100mA (older) or 500mA … Sooo, where’s the remaining 1.9A coming from?
MacBook Pro USB ports will put out close to 2amps to charge an iPod. The USB spec is merely minimums
If you like 5x8, of the 5050’s, then try 16x16:
The question is - what is that much (individually controllable) brightness in such a small space useful for?
I was thinking it could be interesting to make a coffee table like piece with a fresnel lens above the matrix, focused on the ceiling (or just off focus to slightly overlap the blobs from each pixel). By spreading the pixel images over a larger area the brightness might be more useful.
Um, don’t try running this on a USB port - takes 15A full on.
The nice thing about this is less the grid size (mark and I both have a few of the 16x16 sheets) - it’s more that it backpacks onto a arduino nicely. I’m using one of these setups as a always in my laptop bag dev board/system. Makes it easier to do little bits of development here and there with working leds, vs. having to drag a strip or a sheet around in addition to a controller.