Related articles: Wand-Controlled Robot
As a symbol of the magician’s intentionally directed will-power, the wand is an excellent interface for ritual computing with multimedia, and facilitates physical activity in ways that keyboards and mouses do not. Imagine projecting a giant digital sigil onto a wall, and after using the wand to banish the ritual space, you intone an incantation and thrust your wand toward the sigil which promptly ignites in a blaze of virtual fire. Or you could manipulate a virtual poppet, activate a robot servitor or eldritch machine, etc. There are nearly limitless possibilities.
Here is an example of using a Kymera Magic Wand to manipulate an icosahedron on my computer (sorry the animation is so difficult to see):
The Kymera wand is a programmable infrared remote control device developed and sold by The Wand Company in the UK. It is marketed for television RC.
The Kymera can transmit up to 13 distinct infrared signals in response to these distinct actions:
- Rotate anticlockwise
- Rotate clockwise
- Flick upwards
- Flick downwards
- Flick left
- Flick right
- Tap on top
- Tap on side
- Big swish
- Push forward
- Double tap on top
- Double tap on side
- Pull back
The wand contains a vibrator that pulses a number of times to let you know what state the wand is in, similar to the haptic feedback in video game controllers and cellular telephones. Signal programming is a cinch as the wand records signals from other RC devices. For the example in this article, I programmed my wand with a Sony television RC.
To interface with my computer, I am using an Arduino microcontroller with a Parallax IR receiver from Jameco, and Ken Shirriff’s outstanding multi-protocol infrared remote library. The Arduino translates the IR signals into hexadecimal values which it sends to Processing over the serial port. The Processing sketch draws and animates the icosahedron in response to the hex values received.
Source Code
Here is the source code for what is shown in the above demo video.
Arduino
/**
* Wand Test 1 (Arduino)
* by Joshua Madara, hyperRitual.com
* requires IRremote library by Ken Shirriff
* http://www.arcfn.com/2009/08/multi-protocol-infrared-remote-library.html
*/
#include <IRremote.h>
int RECV_PIN = 11;
IRrecv irrecv(RECV_PIN);
decode_results results;
void setup()
{
Serial.begin(57600);
irrecv.enableIRIn(); // start the receiver
}
void loop() {
if (irrecv.decode(&results)) { // if there is something to send
Serial.println(results.value, HEX); // send current value to Processing
irrecv.resume(); // receive the next value
}
}
Processing
/**
* Wand Test 1 (Processing)
* by Joshua Madara, hyperRitual.com
* requires Dimension3D, Shape3D, and Icosahedron by
* Ira Greenburg
* Processing \ Examples \ 3D \ Form \ Icosahedra
*/
import processing.serial.*;
Serial arduinoPort;
Icosahedron ico1;
float xRot = 0;
float yRot = 0;
float zoom = 0;
int sw1 = 0; // switch state variable
void setup(){
size(800, 600, P3D);
arduinoPort = new Serial(this, Serial.list()[1], 57600);
ico1 = new Icosahedron(100);
stroke(255, 0, 0);
noFill();
}
void draw(){
background(0);
lights();
translate(width/2, height/2);
getWandState();
switch(sw1) {
case 1: // rotate down
xRot-=0.05;
break;
case 2: // rotate up
xRot+=0.05;
break;
case 3: // rotate left
yRot-=0.05;
break;
case 4: // rotate right
yRot+=0.05;
break;
case 5: // zoom in
zoom+=5;
break;
case 6: // zoom out
zoom-=5;
break;
}
//pushMatrix();
translate(0, 0, zoom);
rotateX(xRot);
rotateY(yRot);
ico1.create();
//popMatrix();
}
void getWandState() {
while(arduinoPort.available() > 0) {
String inBuffer = arduinoPort.readString();
if(inBuffer != null) {
String theValue = inBuffer.trim();
println(theValue);
if(theValue.equals("210") == true) { // flick down
sw1 = 1;
} else if(theValue.equals("A10") == true) { // flick up
sw1 = 2;
} else if(theValue.equals("410") == true) { // flick left
sw1 = 3;
} else if(theValue.equals("C10") == true) { // flick right
sw1 = 4;
} else if(theValue.equals("E10") == true) { // push forward
sw1 = 5;
} else if(theValue.equals("610") == true) { // pull back
sw1 = 6;
} else if(theValue.equals("110") == true) { // big swish
sw1 = 0;
}
}
}
}
