近づいた/離れた時だけ通信する

前の状態を覚えておく

var dist = 0;
var dist_threshold = 0.2; // 距離のしきい値
var wifeIsHere = false;


serialInit(9600);
//serialSend("this wife is watching me");

while(true) {
  dist = analogRead(0);
  if(dist > dist_threshold){
  	if(!wifeIsHere) serialSend("N");
  	wifeIsHere = true;
  }
  else{
  	if(wifeIsHere) serialSend("F")
  	wifeIsHere = false;
  }
  //serialSend(dist + "\r\n")
}