Introduction: Multi-Touch Interface on the Cheap(really Cheap)
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Step 1: Necesary Objects
For this you will need a Webcam, a Glass Desk, software called roboRealm ( RoboRealm download ). For me i mounted my webcam under my desk with ducktape.
Step 2: The Software and Setup
For this step we will be setting up the software to read and interpret the image. You can download this software from there website www.roborealm.com. iI have not perfected the software for using fingers,kinda hard to seperate them,but..., I do have a pen like thing that I built from random things lying around my room that powers up an LED. The file Pen.robo is for using the LED pen thingy,u can use anything that powers up an LED and for added precision you can put an IR filter over the camera that is made from either a floppy disk drive or a completely dark spot from a negative on camera filem strip, And the file Touch.robo is for using hands but is not perfected.
Step 3: The LED Pen Device
The following pictures(sorry about the quality) are my newest version of the LED pen device, in the picture i have about 6-7 LED's attached but you only need 1 or 2 for extra precision
Materials needed are
3 volt small clock/watch battery x 1
Zip tie x 2
Switch with 2 wires coming out of it
LED's x 1/2 (your choice)
Steps for it are:
1) take the + side and face it down
2) put a wire to the switch on the - side
3) wrap zip tie tightly around battery so wire is held firmly, cut off excess zip tie
4) put tape on battery and zip tie
5) place penney on tape making shure it does NOT touch the battery
6 place second wire to switch on penny
7) tightly tie second zip tie in opposite direction than first one and cut off excess
8) place squares of tape on top/bottom
9) insert LED(s) by taking the long end and bending it up a little and then further down bending it down so the two wires a further apart but still even and parallel with each other
and make shure the - side touches the penny and the + touches the + side of the battery and when you flip the switch it should turn on, this is a very easy/compact way of doing an LED pointer for this project