     // when testing with buttons, however a legal
     // car must past start before finishing
     while (started) {
-      started = sensor_tripped(START_SENSOR, SENSOR_LOW, SENSOR_HIGH);
+      started = sensor_tripped(START_SENSOR, SENSOR_LOW, sensor_high_start);
     }
-    
-    ClearLine(1);
-    DisplayText(0, 0, "Start");
+
+    lcd.clear();
+    DisplayText(0, 0, "Car started   ");
     while (!finished) {
-      finished = sensor_tripped(END_SENSOR, SENSOR_LOW, SENSOR_HIGH);
+      finished = sensor_tripped(END_SENSOR, SENSOR_LOW, sensor_high_end);
     }
     endtime = millis();
     elapsed_time = endtime - starttime;
 
     // debounce finished sensor
     while (finished) {
-      finished = sensor_tripped(END_SENSOR, SENSOR_LOW, SENSOR_HIGH);
+      finished = sensor_tripped(END_SENSOR, SENSOR_LOW, sensor_high_end);
     }
     sprintf(DisplayString, "Elapsed %lu ms", elapsed_time);
     Serial.print(DisplayString);
     Serial.print("\n");
-    ClearLine(0);
-    ClearLine(1);
-    DisplayText(0, 0, "Finished:");
+    lcd.clear();
+    DisplayText(0, 0, "Finished:       ");
     DisplayText(1, 0, DisplayString);
     delay(2500);
   }
 }
 
+
+void BlinkDisplay(int blink_delay) {
+    lcd.noDisplay();
+    delay(blink_delay);
+    lcd.display();
+}
 void ClearLine(int LineToClear) {
   lcd.setCursor(0, LineToClear); //0 is the first and 1 is the second line, x=0
   lcd.print("                "); //Add 16 spaces to clear the line (there may be better ways to do this)

  lcd.setCursor(CursorPos, Line); //0 is the first line and 1 is the second line
  lcd.print(TextToDisplay);
}


    return true;
  }
  return false;
}

int guess_ambient_light(int sensor_id) {
  unsigned long sensor_data = 0;
  for(int i=0;i<SENSOR_SAMPLES;i++) {
    sensor_data += analogRead(sensor_id);
  }
  return int(sensor_data / SENSOR_SAMPLES);
}

void loop() {
