Finish week5 report

week5-5/week5-5.ino

@@ -36,27 +36,27 @@ int get_mode() {
 void show(byte digits[4]) {
   for (int i = 0; i < 4; i++) {
     digitalWrite(LATCH, LOW);
-    shiftOut(DATA, CLK, MSBFIRST, ~digits[i]);
+    shiftOut(DATA, CLK, MSBFIRST, ~digits[i]); // 低態觸發
     digitalWrite(LATCH, HIGH);
-    digitalWrite(scan[3 - i], LOW);
+    digitalWrite(scan[3 - i], LOW); // 點亮一毫秒
     delay(1);
     digitalWrite(scan[3 - i], HIGH);
   }
 }
 
 void mode_display() {
-  static byte digits[4];
-  static byte p = 0;
+  static byte digits[4];  // 所有數字的狀態
+  static byte p = 0; // 現在要改變的數字
   static unsigned long checkpoint = 0;
   show(digits);
   if (millis() - checkpoint > 200) {
     if (p == 4) {
-      // all the numbers are turned on, reset
+      // 所有 LED 皆點亮，重設所有值
       p = 0;
       for (int i = 0; i < 4; i++) digits[i] = 0;
     }
-    digits[p] <<= 1;
-    digits[p] += 1;
+    digits[p] <<= 1;  // 向左移位
+    digits[p] += 1;   // 補一
     if (digits[p] == 0xFF) {
       // if current digit is full, change to the next one
       p++;