limit switches, also EStop switches (emergency) should
always activate low, idle high. it must idle high, because
consider what would happen if it idles low, then the wire
gets inadvertedly disconnected. you wouldn't notice it. 
BUT, you can also just put all estops on an actual hardware
disconnect for best practice. At the risk of frying some 
not robust chips (tradeoff). Though the note for limit switches
remains correct.