heart_beat.ino

#define PIN01 9
#define PIN02 8
#define PIN03 7
#define PIN04 6
#define PIN05 5
#define PIN06 4
#define PIN07 3
#define PIN08 2

#define PIN09 11
#define PIN10 10
#define PIN11 A5
#define PIN12 A4
#define PIN13 A3
#define PIN14 A2
#define PIN15 A1
#define PIN16 A0

#define EDGE_SIZE 8

// default to HIGH
const byte row[EDGE_SIZE] = {
   PIN16, PIN15, PIN11, PIN06, PIN09, PIN04, PIN03, PIN13
};

// default to LOW
const byte col[EDGE_SIZE] = {
  PIN10, PIN14, PIN08, PIN12, PIN01, PIN07, PIN02, PIN05
};

const byte frames[][EDGE_SIZE][EDGE_SIZE] = {
{
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 1, 0, 0, 1, 0, 0, },
  { 0, 1, 3, 3, 3, 3, 1, 0, },
  { 0, 1, 3, 4, 4, 3, 1, 0, },
  { 0, 0, 1, 3, 3, 1, 0, 0, },
  { 0, 0, 0, 1, 1, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
},{
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 1, 0, 0, 1, 0, 0, },
  { 0, 1, 3, 3, 3, 3, 1, 0, },
  { 0, 1, 3, 4, 4, 3, 1, 0, },
  { 0, 0, 1, 3, 3, 1, 0, 0, },
  { 0, 0, 0, 1, 1, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
},{
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 1, 0, 0, 1, 0, 0, },
  { 0, 1, 3, 3, 3, 3, 1, 0, },
  { 0, 1, 3, 4, 4, 3, 1, 0, },
  { 0, 0, 1, 3, 3, 1, 0, 0, },
  { 0, 0, 0, 1, 1, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
},{
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 1, 0, 0, 1, 0, 0, },
  { 0, 1, 3, 3, 3, 3, 1, 0, },
  { 0, 1, 3, 4, 4, 3, 1, 0, },
  { 0, 0, 1, 3, 3, 1, 0, 0, },
  { 0, 0, 0, 1, 1, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
},{
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 1, 0, 0, 1, 0, 0, },
  { 0, 1, 3, 3, 3, 3, 1, 0, },
  { 0, 1, 3, 4, 4, 3, 1, 0, },
  { 0, 0, 1, 3, 3, 1, 0, 0, },
  { 0, 0, 0, 1, 1, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
},{
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 0, 1, 0, 0, 1, 0, 0, },
  { 0, 1, 3, 3, 3, 3, 1, 0, },
  { 0, 1, 3, 4, 4, 3, 1, 0, },
  { 0, 0, 1, 3, 3, 1, 0, 0, },
  { 0, 0, 0, 1, 1, 0, 0, 0, },
  { 0, 0, 0, 0, 0, 0, 0, 0, },
},{
  { 0, 0, 0, 0, 0, 0, 0, 0, },
  { 0, 4, 4, 0, 0, 4, 4, 0, },
  { 4, 4, 4, 4, 4, 4, 4, 4, },
  { 4, 4, 4, 4, 4, 4, 4, 4, },
  { 4, 4, 4, 4, 4, 4, 4, 4, },
  { 0, 4, 4, 4, 4, 4, 4, 0, },
  { 0, 0, 4, 4, 4, 4, 0, 0, },
  { 0, 0, 0, 4, 4, 0, 0, 0, },
},
};

const byte frames_count = sizeof(frames) / EDGE_SIZE / EDGE_SIZE;
const byte loop_count = 2*frames_count - 2;

void setup() 
{
    // Open serial port
    Serial.begin(9600);
    
    // Set all used pins to OUTPUT
    // This is very important! If the pins are set to input
    // the display will be very dim.
    for (byte i = 0; i < EDGE_SIZE; i++) {
        pinMode(row[i], OUTPUT);
        digitalWrite(row[i], HIGH);
    }

    for (byte i = 0; i < EDGE_SIZE; i++) {
        pinMode(col[i], OUTPUT);
        digitalWrite(col[i], LOW);
    }
}

byte cursor = 0;
void loop() {
  byte fi = cursor < frames_count ? cursor : loop_count-cursor;
  auto frame = frames[fi];
  for (byte i = 0; i < 150; i++) {
    byte level = i % 4;
    for (byte r = 0; r < EDGE_SIZE; r++) {
      digitalWrite(row[r], LOW);
      for (byte c = 0; c < EDGE_SIZE; c++) {
        byte grade = frame[r][c];
  
        digitalWrite(col[c], grade > level ? HIGH : LOW);
  
        digitalWrite(col[c], LOW);
      }
      digitalWrite(row[r], HIGH);
    }
  }
  cursor = (cursor + 1) % loop_count;
}