007 Recommended-power-supplies-for-the-Arduino-Uno
http://txplo.re/2f0zfrj

007 Learn-about-communications-protocols
http://txplo.re/2gHu2dH

009 Learn-about-floating-pins
http://txplo.re/2foLFft

009 Learn-about-pull-up-and-pull-down-resistors
https://www.txplore.com/blog/1364317/pullupdownresistors

010 Learn-about-PWM
http://txplo.re/2fXdc6z