I am working on building a wordclock using one of the several design ideas that you can find all over the Internet. Something like a mix of this one: http://www.instructables.com/id/Sleek-word-clock/ and this one: http://www.instructables.com/id/Personalised-Word-Clock/ A lot of the guides suggested building your own Arduino to save money, but I found these Arduino Nano clones for $7/apiece: http://www.amazon.com/gp/product/B00SGMEH7G.
I've done a few simple projects before, but nothing with the same kind of power demand. How can I figure out the power requirements? My plan is to use approximately 64 3mm LEDs via shift register, or possibly the equivalent segments of an LED strip.
The Nano clone does not have a barrel connector for external power adaptor. Should I directly solder on the power cables from an external adaptor? Use a screw terminal or similar? Is the USB adaptor a good enough source of power for 64 LEDs? Or do I have to do something else to supply external power to that many LEDs?
Thanks for any advice! I am experienced in programming but not in electrical engineering so many of the concepts are something I don't have a good handle on yet.