This instructable will show you how to construct a basic interactive laser-sensitive target, great for those just getting started with Arduino. This could easily be used as a platform for a laser tag system, or just something fun to play with! It might also drive your cat insane. Here's what you'll need to build it:
- an Arduino board (I used UNO)
- 4 red LEDs (you could always change the colors or use multicolored LEDs)
- 3 green LEDs
- 1 blue LED
- 1 photosensitive resistor
- 1 5k potentiometer to adjust sensitivity
- A solderless breadboard or MakerShield
- an hour or two, and some patience!
- the Arduino IDE installed on your computer.
Step 1: Build the Circuit
I built this on a Maker Shield, but you could build this project on anything! This circuit is very straightforward. The four red LEDs are connected to pins 8,9,10,11; the three green LEDs are connected to 2,3,4; and the blue LED is connected to pin 12. (All LEDs are also connected to ground)
The sensor consists of a 5k potentiometer and a photo-resistor. The middle pin on the potentiometer is connected to ground on the Arduino and the other pin on the potentiometer is connected to analogue pin 0, or A0, on the Arduino. The photo-resistor is connected to +3.3 volts on the Arduino and to the A0 pin on the Arduino.
Your almost done!
Step 2: Program the Arduino
Download the zip folder and unzip it. In it is the program for the Arduino. Now open the file in the Arduino IDE and upload it to your Arduino! Make sure you have the Arduino plugged in to your computer and make sure you have the newest version of Arduino. Once you have the program loaded onto the Arduino, the four red lights should blink on and off in sequence.
Step 3: Have Fun!
Now get a standard 5mw red laser pointer and try pointing it at the photo-resistor! The blue light should turn on and the three green lights should blink on as well. If nothing happens, try adjusting the potentiometer to increase or decrease sensitivity. You can change things in the Arduino program as well. If you are still having issues, let me know in the comments and I might be able to help you.
You could easily use this as a base for a laser tag system with a few modifications to the program. You could also re-program the Arduino to use the green and blue LEDs as a health bar or something. The possibilities are endless! But remember kids, DON'T POINT LASERS IN ANYONE'S EYES!