Reaction Timer

1. Before you start

This lesson will use a LCD this is the reason why you are invited to read  the lesson Arduino & LCDs before you start.

2. Schematic

The schematic is very simple. There are all the connections needed to use the LCD and three buttons that from left to right are UP, DOWN and START/STOP.

3. How does it work?

When the Arduino is powered on you'll be invited to set a countdown. Use the UP and DOWN button to choose the count and the START/STOP button to choose it. After a countdown will start and when the GO signal will appear on the screen you have to press the START/STOP button as soon as possible.

In base of your score a different message will appear on the screen:

• Well done! if 0 < elapsed <= 350;

• Not bad! if 350 < elapsed <= 500;

• Try again please otherwise;

4. The code

Here is the code:

/*
Test your ability with the Reaction Timer
 author: Arturo Guadalupi 
 */
 
// include the library code:
#include 
 
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
 
int count = 0;
 
void setup() {
  lcd.begin(16, 2);
  pinMode(10, OUTPUT);
  pinMode(A0, INPUT); //UP button
  pinMode(A1, INPUT); //DOWN button
  pinMode(A2, INPUT); //START/STOP button
  
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Arduino");
  lcd.setCursor(0, 1);
  lcd.print("Reaction Timer!");
  delay(2000);
  lcd.clear();
  delay(1000);
}
 
void loop() {
  SetCountdown(); //function to set the countdown
  countdown();    //function for the countdown
  reaction();     //function who count your reaction
}
 
void SetCountdown()
{
  lcd.clear();
  lcd.print("Please set the");
  lcd.setCursor(0, 1);
  lcd.print("countdown");
  delay(2000);
  lcd.clear();
  
  while (digitalRead(A2) != LOW) //while you not press START
  {
    if (digitalRead(A0) == LOW) //if UP is pressed
    {
      count++;
      delay(200);
      lcd.clear(); 
    }
    if (count > 10) //10 seconds are enough to prepare yourself!
      count = 0;
 
    if (digitalRead(A1) == LOW) //if DOWN is pressed
    {
      count--;
      delay(200);
      lcd.clear(); 
    }
    
    if (count  350 && elapsed  500)
    lcd.print("Try again please");
  delay(1500);
}