Original HERE: http://tsjwang.blogspot.com/2013/09/star-trek-target-practice.html

I guess I was watching a bit too much Star Trek with my brother. I decided to make a phaser.
Some of you may know that there are multiple types of phasers. I modeled mine after one of these....

HERE IS A VIDEO, basically this whole instructables.

Step 1: Schematic

Here is the schematic.

And a parts list:

Target

- Phototransistors
- two NPN transistors
- $1 calculator
- Some resistor
- 1.5v battery and casing

Phaser

- ATTiny25, 45, 85
- switch
- 2x pushbutton
- piezo buzzer
- 3x resistors (one for LED, two pulldown)
- NPN transistor
- LASER BEAMZ
- OPTIONAL - AVR ISP header

The schematic should explain. Attached is the code.

phaser.zip
Download

Step 2: Just a Tip on Taking Apart the Calculator

Like I said in the video, I'm only using the = button on the calculator.

First take the calculator apart. you should be able to find the place where the rubber thing touches the board. Those are two contacts of a switch. Now trace those contacts until you find a spot where you can solder wires to.

You should have four wires after, Vcc, GND, =1, =2.

To find out out where to connect =1 and =2 on the transistor, just test out both ways! It's one or the other.

Step 3: Some Pics of the Phaser

I didn't talk much about how to actually paint, glue, cut the phaser.

Well, I used an old paper towel roll as the handle, and leftovers from a pin wood derby car as the body.

I cut them to shape, glued them together, and painted them black.
After that I completed the electronics and glued those on too.