placing

src/main.cpp

@@ -23,6 +23,8 @@ typedef struct {
   short pin;
   // elapsed time for pin (0 means not finished)
   unsigned int elapsedTime;
+  // placing
+  unsigned int place;
 } Car;
 
 // assume all cars are on sequential digital pins
@@ -63,6 +65,7 @@ void setup()
 void resetCars() {
   for(short i=0; i<CAR_COUNT; i++) {
     cars[i].elapsedTime = 0;
+    cars[i].place = 0;
   }
 }
 
@@ -70,31 +73,15 @@ void displayTimers() {
   short row = 0;
   lcd.clear();
 
-  // keep track of cars that we've already printed a score for
-  bool seenCar[CAR_COUNT];
-  for (int i=0; i<CAR_COUNT; i++) {
-    seenCar[i] = false;
-  }
-
-  for(short place=0; place<min(CAR_COUNT, DISPLAY_LINES); place++) {
-
-    // find which is the fastest car that hasn't already been processed
-    short currentCar = -1;
-    for (short i=0; i<CAR_COUNT; i++) {
-      if (!seenCar[i] && cars[i].elapsedTime != 0 && (currentCar == -1 || cars[i].elapsedTime < cars[currentCar].elapsedTime)) {
-        currentCar = i;
+  for(unsigned short place=1; place<=min(CAR_COUNT, DISPLAY_LINES); place++) {
+    for (int i=0; i<CAR_COUNT; i++) {
+      if (cars[i].place == place) {
+        // only print the score if this car finished
+        lcd.setCursor(0,place-1);
+        sprintf(buffer, "%d%s: CAR%d @ %0.2fs", place, place==1?"st":(place==2?"nd":(place==3?"rd":"th")) , i+1, cars[i].elapsedTime/1000.0);
+        lcd.print(buffer);
       }
     }
-
-    // mark car as seen so we don't show the same car again
-    seenCar[currentCar] = true;
-
-    if (cars[currentCar].elapsedTime != 0) {
-      // only print the score if this car finished
-      lcd.setCursor(0,row++);
-      sprintf(buffer, "%d%s: CAR%d @ %0.2fs", place+1, place==0?"st":(place==1?"nd":(place==2?"rd":"th")) , currentCar+1, cars[currentCar].elapsedTime/1000.0);
-      lcd.print(buffer);
-    }
   }
 }
 
@@ -106,7 +93,8 @@ unsigned long startTime;         // start time in ms
 #define STATE_RUNNING 2
 #define STATE_DONE 3
 
-short state = 0;
+unsigned short state = 0;
+unsigned short place = 0;
 
 void loop()
 {
@@ -117,6 +105,7 @@ void loop()
       lcd.clear();
       lcd.setCursor(0,0);
       lcd.print("Ready...");
+      place = 0;
       resetCars();
       digitalWrite(PIN_LED, HIGH);
     }
@@ -137,8 +126,15 @@ void loop()
       for(short i = 0; i<CAR_COUNT; i++) {
         if (cars[i].elapsedTime == 0) {
           if (digitalRead(cars[i].pin) == LOW) {
+            place++;
             // car finished, record time
             cars[i].elapsedTime = elapsedTime;
+            cars[i].place = place;
+            if (place < DISPLAY_LINES) {
+              lcd.setCursor(0,place-1);
+              sprintf(buffer, "%d%s: CAR%d @ %0.2fs", place, place==1?"st":(place==2?"nd":(place==3?"rd":"th")) , i+1, cars[i].elapsedTime/1000.0);
+              lcd.print(buffer);
+            }
           } else {
             allDone = false;
           }
@@ -148,7 +144,7 @@ void loop()
       // stop race if all cars are done or MAX TIME exceeded
       if (allDone || elapsedTime > MAX_TIME) {
         state = STATE_DONE;
-        displayTimers();
+        //displayTimers();
       }
 
     }