Ready… Set… Go! Test your reaction time!

In this game, one of three LEDs will randomly light up. You must tap the corresponding capacitive sensor as quick as possible. If you don’t react fast enough, the game is over.

Materials

Instructions

1. Attach the shield onto the top of the Arduino board.
   
2. Connect three LEDs across breadboard gap.
   
3. Connect a 220 ohm resistor to digital pin 9. Connect the resistor to the long leg of the first LED.
4. Connect each of the digital pins 10 and 11 to the corresponding LED following the same method.
   
5. Connect the short leg of the LEDs to GND pin using black jumper wires.
   
6. Connect the piezo speaker to the breadboard and connect one leg to digital pin 8 and the other to GND.
   
7. Using a separate breadboard, connect a 1 M ohm resistor between digital pin 3 and digital pin 2.
   
8. Connect digital pins 4 and 5 to digital pin 2 following the same method.
   
9. Make a touch sensor by cutting a 5 cm x 5 cm square of aluminium foil. Wrap one corner of a foil square to a loose wire – the metal of the wire must contact the foil.
   
10. Make three capacitive sensors and connect each to digital pins 3 through 5 – tape the three sensors firmly to the table making sure they do not touch.
    
11. Connect the Arduino assembly to the computer, upload example ‘React’ and try out the game.
    

Code

Find the code in File>Examples>EducationShield>Block2-Sports>Projects>React

How it works

• The CapacitiveSensor and EducationShield libraries are included.
• pitches.h is included, the file containing the definitions of the notes.
• The VU-meter variables are declared, ledPins[], pinCount and LEDs.
• An array to hold the three CapacitiveSwitch objects is declared.
• The variable reactTime is declared to hold the reaction time in milliseconds.
• The Melody object is declared.
• In setup(), the VU-meter and capacitive switches are configured and initialized.
• In loop(), the program pauses for a random period of time, somewhere between 50 and 2000 milliseconds.
• The variable target is declared and given a random value between 0 and 3.
• The LED in the position of the target number is turned on.
• If the capacitive sensor in the position of the target number is pressed within the react time, the LED is turned off again.
• A short melody is defined by declaring the variables melody[], noteDurations[] and numberOfNotes.
• The melody is played.
• If the capacitive sensor in the position of the target number is not pressed within the react time, the program jumps to the function gameOver().
• In gameOver(), all LEDs are turned on.
• A short melody is defined by declaring the variables melody[], noteDurations[] and numberOfNotes.
• The melody is played.
• All LEDs are blinked.
• All LEDs are turned off.
• The program jumps back to the same place in loop().
• loop() continues to loop.

Troubleshooting

• Refer to the illustration and double check your connections. Make sure the shield and wires are firmly connected. Check the LED polarities to make sure they are consistent and properly wired.
• Increase the allowed reaction time to make the game easier for testing. Make sure to change them back when everything is working.
• If the VU-meter does not work correctly, see VU-Meter reference for debugging VU-meter.
• If the capacitive sensor does not work, see reference CapacitiveSwitch for debugging.

Learn by doing

• Increase game difficulty: change the reaction time and the waiting time.
• Make up your own melodies: change the tones and make a song.
• Improve the game over reaction: change the way the LEDs blink when it is game over. See the VU-meter reference for the commands you can use.
• Add more components: try adding more LEDs and sensors. Do not forget to add them both onto the board and into the code.