#include <LiquidCrystal.h>
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
int LEDR = 8; // Pin connected to red LED
int LEDB = 7; // Pin connected to blue LED
int LEDGr = 6; // Pin connected to green LED
int Button = 9; // Pin connected to pushbutton
int COLOR; // Variable color
int Beep;
int PSE; // Variable pause
int TME; // Time
int RTME = 0; // Reaction time
void setup() {
 lcd.begin(16, 2);
 pinMode(LEDR, OUTPUT); // Set LED pins as output
 pinMode(LEDB, OUTPUT);
 pinMode(LEDGr, OUTPUT);
 pinMode(Button, INPUT); // Set pushbutton as input
 digitalWrite(LEDR, LOW); // Switch on all LED colors
 digitalWrite(LEDB, LOW);
 digitalWrite(LEDGr, LOW);
}
void loop() {
 lcd.clear(); // Clear screen
 lcd.print("Hold Button to"); // Display message on LCD screen
 lcd.setCursor(0, 1); // Move to second line
 lcd.print("start.");
 while (digitalRead(Button) == LOW) { // Test does not start until
 // button is pushed (and held)
 tone(13, 1200, 30);
 delay(1400);
 noTone(13);
 }
 lcd.clear();
 digitalWrite(LEDR, HIGH); // Switch off start light
 digitalWrite(LEDB, HIGH);
 digitalWrite(LEDGr, HIGH);
 randomSeed(analogRead(0)); // Random noise from pin 0
 COLOR = random(1, 4); // Generate random color
 PSE = random(500, 1200); // Set random pause duration between lights
 // Repeat this loop while color is green or blue AND pushbutton 
 // is held
 while (COLOR != 1 && digitalRead(Button) == HIGH) {
 digitalWrite(LEDGr, HIGH);
 digitalWrite(LEDB, HIGH);
 delay(PSE);
 randomSeed(analogRead(0));
 Beep = random(1, 4); // Select random beep from buzzer 
 // (buzzer beeps 1 in 3 times)
 PSE = random(750, 1200); // Select random pause duration between 
 // lights (to increase surprise effect)
 if (Beep == 1) {
 tone(13, 1600, 350);
 delay(750);
 noTone(13);
 }
 if (COLOR == 2) {
 digitalWrite(LEDGr, LOW);
 }
 if (COLOR == 3) {
 digitalWrite(LEDB, LOW);
 }
 delay(PSE);
 randomSeed(analogRead(0));
 COLOR = random(1, 4); // Select random color
 }
 // Execute this loop if color is red
 if (COLOR == 1 && digitalRead(Button) == HIGH) { 
 digitalWrite(LEDGr, HIGH);
 digitalWrite(LEDB, HIGH);
 delay(PSE);
 TME = millis(); // Record time since program has started
 digitalWrite(LEDR, LOW);
 while (digitalRead(Button) == HIGH) { // Runs until button is 
 // released, recording the 
 // reaction time
 delay(1);
 }
 lcd.display();
 RTME = millis() - TME; // Reaction time in ms
 lcd.print("Reaction Time:"); // Display on LCD screen
 lcd.setCursor(0, 1);
 lcd.print(RTME);
 }
// Execute if color is NOT red but the pushbutton is released
 if (COLOR != 1) {
 lcd.print("Released too");
 lcd.setCursor(0, 1); // Move to second line
 lcd.print("soon!!!");
 tone(13, 3000, 1500);
 delay(500);
 noTone(13);
 }
 // Test does not restart until the button is pushed once
 while (digitalRead(Button) == LOW) {
 delay(10);
 }
 digitalWrite(LEDR, LOW); // Reset all lights to begin again
 digitalWrite(LEDB, LOW);
 digitalWrite(LEDGr, LOW);
 lcd.clear();
 lcd.print("Hold Button to");
 lcd.setCursor(0, 1);
 lcd.print("start.");
 int Time = 0;
 delay(1000);
}