// MCU BASIC: https://www.basic4mcu.com
// DateTime : 2019-02-01 오전 10:54:35
// by Ok-Hyun Park
//
unsigned long t_tri[3]={0,};
unsigned int  tri_cnt=0,t_fade=0,t0_cnt=0,t1_cnt=0,t2_cnt=0,t3_cnt=0;
int fadingRGB_ledPin[3]={5,6,9}; // 핀 위치(G R B)
int fadeRGBValue[3]    ={0,0,0}; // 0부터 밝기 시작
int fadeRGBDir[3]      ={1,1,1}; // Led를 밝게함.0으로하면 처음에 꺼져있는듯...
//
void distancetriple_loop(){
  if(t_flag){
    for(int i=0; i<3; i++){
        if(t-t_tri[i]>50){ t_tri[i]=t; //t는 currentmillis임    해석: if(currentmillis-previousmillis[i]>50){ previousmillis[i]=currentmillis;
          if(tri_cnt<256){ //0부터 255까지의 구간
            if(++t0_cnt>=1){ t0_cnt=0; //++c0_cnt>=1 의 숫자 1을 올릴수록 느려짐
              t_fade=tri_cnt;
              if(fadeRGBDir[i]==1){ // led를 밝게함
                if(fadeRGBValue[i]==255){
                  if(++fadeRGBValue[i]==255)fadeRGBDir[i]=0;
                }
              }
            }
          }
          else if(tri_cnt<512){ //256부터 511까지의 구간
            if(++t1_cnt>=1){ t1_cnt=0;
              t_fade=tri_cnt-256; //fade=511-neo_cnt는 감소
              if(fadeRGBValue[i]>0){
                if(--fadeRGBValue[i]==0){ fadeRGBValue[i]=0; fadeRGBDir[i]=1; if(digitalRead(13)==0)t_flag=0; }
              }
            }
          }
          else if(tri_cnt<764){ //512부터 763까지의 구간
            if(++t2_cnt>=1){ t2_cnt=0; t_fade=tri_cnt-512; } //fade=neo_cnt-512는 증가
          }
          else{ // if(neo_cnt<1024)
            if(++t3_cnt>=1){ t3_cnt=0; t_fade=1023-tri_cnt; } //fade=neo_cnt-765는 감소
          }
          //
          if(++tri_cnt>=1024)tri_cnt=0; //-----------------------------------------//
        }
        //
        if(i==2)analogWrite(fadingRGB_ledPin[i],fadeRGBValue[i]/8); // 해설: if(i==1)...../4  1번핀을 /4정도만 증가 시킨다.(i=0은 5번핀 i=1은 6번 핀 i=2는 9번핀임)
        else    analogWrite(fadingRGB_ledPin[i],fadeRGBValue[i]);
        //
        if(digitalRead(13)==0)t_flag=0;
      }
    }
  }
 
코드가 복잡해서 점점 봐드리기 어렵습니다. ^^