diff --git a/8By8/8By8.ino b/8By8/8By8.ino
index 7426736..17a884c 100644
--- a/8By8/8By8.ino
+++ b/8By8/8By8.ino
@@ -9,10 +9,48 @@ class Cube {
 private:
   static int layer_count;
   static int brightness_count;
+  static bool blinking_LED_status;
 
 public:
   // Every int represents a row of 8 LED status.
-  static int LED_status[8][8];
+  static uint16_t LED_status[8][8];
+  static uint16_t LED_brightness[8][8];
+  static uint8_t LED_blinking_status[8][8];
+
+  static void set_blinking(int x, int y, int z) {
+    // 1 = enable blinking
+    if (x >= 8 || x < 0 || y >= 8 || y < 0 || z >= 8 || z < 0) {
+      return;
+    }
+    LED_blinking_status[z][x] = LED_blinking_status[z][x] | (1 << y);
+  }
+
+  static void unset_blinking(int x, int y, int z) {
+    if (x >= 8 || x < 0 || y >= 8 || y < 0 || z >= 8 || z < 0) {
+      return;
+    }
+    LED_blinking_status[z][x] = LED_blinking_status[z][x] & (~1 << y);
+
+    LED_status[z][x] = (LED_status[z][x] & (~(3 << (y * 2)))) |
+                       (LED_brightness[z][x] & (3 << (y * 2)));
+  }
+
+  static void do_blinking() {
+    blinking_LED_status ^= 1;
+    for (int i = 0; i < 8; i++) {
+      for (int j = 0; j < 8; j++) {
+        for (int k = 0; k < 8; k++) {
+          if (LED_blinking_status[i][j] >> k & 1) {
+            if (blinking_LED_status) {
+              LED_status[i][j] = LED_brightness[i][j];
+            } else {
+              LED_status[i][j] = LED_status[i][j] & (~(3 << (k * 2)));
+            }
+          }
+        }
+      }
+    }
+  }
 
   static void display() {
     // Serial.println("Here");
@@ -46,53 +84,61 @@ public:
     brightness %= 4;
     LED_status[z][x] =
         (LED_status[z][x] & (~(3 << (y * 2)))) | (brightness << (y * 2));
+    LED_brightness[z][x] =
+        (LED_brightness[z][x] & (~(3 << (y * 2)))) | (brightness << (y * 2));
   }
 
   static int get_status(int x, int y, int z) {
-    return LED_status[z][x] >> (y * 2) & 3;
+    return LED_brightness[z][x] >> (y * 2) & 3;
   }
 
   static void clear() {
     for (int i = 0; i < 8; i++) {
       for (int j = 0; j < 8; j++) {
+        LED_brightness[i][j] = 0;
         LED_status[i][j] = 0;
       }
     }
   }
 
-  static void draw_line(int x, int y, int z, int length, int direction, int brightness) {
-    if (x >=8 || x < 0 || y >=8 || y < 0 || z >= 8 || z < 0) {
+  static void draw_line(int x, int y, int z, int length, int direction,
+                        int brightness) {
+    if (x >= 8 || x < 0 || y >= 8 || y < 0 || z >= 8 || z < 0) {
       return;
     }
-    if (direction >= 3 || direction < 0 || length <= 0 || brightness >= 4 || brightness < 0) {
+    if (direction >= 3 || direction < 0 || length <= 0 || brightness >= 4 ||
+        brightness < 0) {
       return;
     }
     // 0: x
     // 1: y
     // 2: z
     switch (direction) {
-      case 0:
-        for (int i = 0; i < length; i++) {
-          set_status(x + i, y, z, brightness);
-        }
-        break;
-      case 1:
-        for (int i = 0; i < length; i++) {
-          set_status(x, y + i, z, brightness);
-        }
-        break;
-      case 2:
-        for (int i = 0; i < length; i++) {
-          set_status(x, y, z + i, brightness);
-        }
-        break;
+    case 0:
+      for (int i = 0; i < length; i++) {
+        set_status(x + i, y, z, brightness);
+      }
+      break;
+    case 1:
+      for (int i = 0; i < length; i++) {
+        set_status(x, y + i, z, brightness);
+      }
+      break;
+    case 2:
+      for (int i = 0; i < length; i++) {
+        set_status(x, y, z + i, brightness);
+      }
+      break;
     }
   }
 };
 
 int Cube::layer_count = 0;
 int Cube::brightness_count = 0;
-int Cube::LED_status[8][8] = {0};
+uint16_t Cube::LED_status[8][8] = {0};
+uint16_t Cube::LED_brightness[8][8] = {0};
+uint8_t Cube::LED_blinking_status[8][8] = {0};
+bool Cube::blinking_LED_status = false;
 int bright = 3;
 
 void setup() {
@@ -104,18 +150,33 @@ void setup() {
   Timer1.setPeriod(TIME_PER_LAYER_IN_US);
   Timer1.attachInterrupt(Cube::display);
 
+  cli();
+  TCCR4A = 0; // set entire TCCR1A register to 0
+  TCCR4B = 0; // same for TCCR1B
+  TCNT4 = 0;  // initialize counter value to 0
+  // set compare match register for 1hz increments
+  OCR4A = 7500 / 1; // = (16*10^6) / (1*1024) - 1 (must be <65536)
+  // turn on CTC mode
+  TCCR4B |= (1 << WGM12);
+  // Set CS12 and CS10 bits for 1024 prescaler
+  TCCR4B |= (1 << CS12) | (1 << CS10);
+  // enable timer compare interrupt
+  TIMSK4 |= (1 << OCIE4A);
+  sei();
+
+  Cube::set_blinking(1, 1, 1);
   Serial.begin(115200);
 }
 
 void loop() {
-
   for (int i = 7; i >= 0; i--) {
     for (int j = 0; j < 8; j++) {
       for (int k = 0; k < 8; k++) {
-        Cube::set_status(i, j, k, bright);
+        Cube::set_status(i, j, k, 3);
         delay(5);
       }
     }
   }
-  bright = (bright + 1) % 4;
-}
\ No newline at end of file
+}
+
+ISR(TIMER4_COMPA_vect) { Cube::do_blinking(); }
\ No newline at end of file