   pinMode(7, OUTPUT);
   pinMode(8, OUTPUT);
   pinMode(9, OUTPUT);
-  writeDot(0);  // start with the "dot" off
+  clearDot();
+  Serial.begin(9600);
 }
 
 void writeDot(byte dot) {
   digitalWrite(9, dot);
 }
 
+void clearDot() {
+  writeDot(0);
+}
+
+void blinkDot(byte times) {
+  for (byte count = 1; count <= times * 2; count++) {
+    writeDot(count % 2);
+    delay(1000);
+  }
+}
+
+
+// set display to `digit` [0..9]
 void sevenSegWrite(byte digit) {
+  Serial.print("digit:");
+  Serial.println(digit);
   byte pin = 2;
   for (byte segCount = 0; segCount < 7; ++segCount) {
     digitalWrite(pin, seven_seg_digits[digit][segCount]);

// Note that these patterns are for common cathode displays
// For common anode displays, change the 1's to 0's and 0's to 1's
// 1 = LED on, 0 = LED off, in this order:
//                                    Arduino pin: 2,3,4,5,6,7,8
byte seven_seg_digits[10][7] = { { 1,1,1,1,1,1,0 },  // = 0
                                                           { 0,1,1,0,0,0,0 },  // = 1
                                                           { 1,1,0,1,1,0,1 },  // = 2
                                                           { 1,1,1,1,0,0,1 },  // = 3
                                                           { 0,1,1,0,0,1,1 },  // = 4
                                                           { 1,0,1,1,0,1,1 },  // = 5
                                                           { 1,0,1,1,1,1,1 },  // = 6
                                                           { 1,1,1,0,0,0,0 },  // = 7
                                                           { 1,1,1,1,1,1,1 },  // = 8
                                                           { 1,1,1,0,0,1,1 }   // = 9
                                                           };

void setup() {
  pinMode(2, OUTPUT);

}

void loop() {
  // countdown 9,8,7..0
  for (byte count = 10; count > 0; count--) {
    sevenSegWrite(count - 1);
    delay(1000);
  }
  blinkDot(4);
}
