added leds_blink

leds_blink.cpp

@@ -0,0 +1,30 @@
+const int second = 50;
+
+void setup() {
+  // put your setup code here, to run once:
+
+  for(int i=13;i>=6;i--){
+  pinMode(i,OUTPUT);
+  }
+}
+
+void up(int led,int second) {
+  digitalWrite(led,HIGH);
+  delay(second);
+}
+
+void down(int led,int second) {
+  digitalWrite(led,LOW);
+  delay(second);
+}
+
+void loop() {
+  // put your main code here, to run repeatedly:
+  for(int j=13;j>=6;j--){
+    up(j,second);
+  }
+
+  for(int j=13;j>=6;j--){
+    down(j,second);
+  }
+}