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By fizBANG
#199581
I'm looking for any suggestions or watchouts on projects involving the lumenati boards. I am hoping to drive two of the 8 LED round boards from a single arduino pro mini 5v. I have to do this via batteries, as it'll be part of a wearable. Is this even possible?

The hookup guides for the lumenati show use of a PCA9306 Level Translator Breakout which I am assuming that I don't need since it's already a 5v board.

Or should I consider using a separate battery source for the lumenati (not ideal) and keep the PCA9306 in there?
By Valen
#199944
One of those led chip takes 25 mA on it's own according to the APA102C datasheet. (Though the hookup guide mentions 60mA per unit!) Times 16 led units. At full brightness the extra load of the pro mini won't matter much. But yeah, technically you should add the pro mini board miliAmps consumption to it ( I don't know how much, it depends. Measure!) For how long/many hours do you need it? Then do the numbers for how many Amps*hours you need for batteries. Then choose larger, not smaller, or it won't last as much.

The level translator should not be needed as both are 5 volt devices. Generally speaking a powerbank would work as they provide 5 volt. Though considering the maximum current load a USB cable/connector might not be appropriate. Maybe hack a jack plug into it with thicker wires.