diff --git a/led.c b/led.c
index 5c328e9..78e4ad0 100644
--- a/led.c
+++ b/led.c
@@ -20,6 +20,7 @@ tColor matrix[SIZE][SIZE] = {
     { OFF, OFF, OFF, OFF }
 };
 
+
 void ledSetMatrix(uint8_t col, uint8_t row, tColor color) {
     if ((col < SIZE) && (row < SIZE)) {
         matrix[col][row] = color;
diff --git a/led.h b/led.h
index 72c9a98..7bb712a 100644
--- a/led.h
+++ b/led.h
@@ -19,5 +19,4 @@ void ledInit();
 void ledExec();
 void ledSetMatrix(uint8_t col, uint8_t row, tColor color);
 
-
 #endif /* LED_H_ */
diff --git a/pattern.c b/pattern.c
index d0ba4bb..0d6b289 100644
--- a/pattern.c
+++ b/pattern.c
@@ -4,7 +4,8 @@
 #include <stdlib.h>
 
 
-
+/*
+ * traversing the whole matrix
 void patternExec() {
     static uint8_t i = 0;
     static uint8_t j = 0;
@@ -21,7 +22,48 @@ void patternExec() {
     }
     ledSetMatrix(i, j, BLUE);
 }
+*/
 
+void patternExec() {
+    static uint8_t state = 0;
+    static uint8_t column = 0;
+
+    switch (state) {
+        case 0:
+            // initialize
+            ledSetMatrix(0, 0, BLUE);
+            ledSetMatrix(1, 0, BLUE);
+            ledSetMatrix(2, 0, BLUE);
+            ledSetMatrix(3, 0, BLUE);
+            state = 1;
+            break;
+        case 1: 
+            // select new column, row 1
+            column = ((uint8_t) rand()) & 0x3;
+            ledSetMatrix(column, 1, BLUE);
+            state = 2;
+            break;
+        case 2:
+            // same column, row 2
+            ledSetMatrix(column, 2, BLUE);
+            ledSetMatrix(column, 1, OFF);
+            state = 3;
+            break;
+        case 3:
+            // same column, row 3
+            ledSetMatrix(column, 3, BLUE);
+            ledSetMatrix(column, 2, OFF);
+            state = 4;
+            break;
+        case 4:
+            // same column, row 3 off
+            ledSetMatrix(column, 3, OFF);
+            state = 1;
+        default:
+            state = 0;
+            break;
+    }
+}
 
 void patternInit() {
     schAdd(patternExec, NULL, 0, 500);