Charlieplexing 20LED test

Charlieplexing.ino

// Charlieplexing
// 20150319 @houmei
//

#define MAXCharlie 5
int Charlie[] = { 12,11,10,9,8 };

int CA[] = {
  0,1, 0,2, 0,3, 0,4, 1,2, 1,3, 1,4, 2,3, 2,4, 3,4
};
int CB[] = {
  1,0, 2,0, 3,0, 4,0, 2,1, 3,1, 4,1, 3,2, 4,2, 4,3
};


void setup() {
  all_off();
}

int pos = 0;
int dir = 1;

void loop() {
  all_off();
  turn_on(pos);
  pos = pos + dir;
  if (pos>=20) {
    pos=19;
    dir = -1;
  }
  if (pos<0) {
    pos=0;
    dir = 1;
  }
  delay(30);
}

void all_off() {
  for(int i=0; i<MAXCharlie; i++) {
    pinMode(Charlie[i],INPUT);
  }
}

void turn_on(int num) {
  int pA,pB,xA,xB;
  if (num>=0 && num <20) {
    xA = CA[num]; xB = CB[num]; // get Chari¥lieplex Index
    pA = Charlie[xA] ; pB = Charlie[xB]; // get Charlieplex port No.
    pinMode(pA,OUTPUT);
    pinMode(pB,OUTPUT);
    digitalWrite(pA,LOW);
    digitalWrite(pB,HIGH);
  }
}