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Having one of those days where your too lazy to do anything? Have a robot doodle for you while you sit back in your favorite chair. This is a very simple drawing robot that was actually started by one of our student engineers. I just made the base plate bigger so I could add a third servo to raise and lower the pen.

My base plate is laser cut acrylic but it could easily have been a small food container, CD or a piece of wood. Just use some double sided tape or hotglue to hold it all together.

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Components Required for this project:

• Arduino UNO
• Breadboard
• 9 LEDs
• 9 x 330 ohm resistors
• Wires to connect the circuit
• USB connection cable: to connect the computer to the Arduino
• A computer: to run the processing sketch, and to compile / upload the Arduino sketch
• Processing Program installed on computer
• Arduino Program installed on the computer

Arduino Sketch

Arduino Code

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/* This program was created by ScottC on 9/5/2012 to receive serial 
signals from a computer to turn on/off  1-9 LEDs */

void setup() {                
  // initialize the digital pins as an output.
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
// Turn the Serial Protocol ON
  Serial.begin(9600);
}

void loop() {
  byte byteRead;

   /*  check if data has been sent from the computer: */
  if (Serial.available()) {
  
    /* read the most recent byte */
    byteRead = Serial.read();
    //You have to subtract '0' from the read Byte to convert from text to a number.
    byteRead=byteRead-'0';
    
    //Turn off all LEDS
    for(int i=2; i<11; i++){
      digitalWrite(i, LOW);
    }
    
    if(byteRead>0){
      //Turn on the relevant LEDs
      for(int i=1; i<(byteRead+1); i++){
        digitalWrite(i+1, HIGH);
      }
    }
  }
}

Processing Code

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//Created by ScottC on 12/05/2012 to send mouse coordinates to Arduino

import processing.serial.*;

// Global variables
int new_sX, old_sX;
int nX, nY;
Serial myPort;

// Setup the Processing Canvas
void setup(){
  size( 800, 400 );
  strokeWeight( 10 );
 
  //Open the serial port for communication with the Arduino
  //Make sure the COM port is correct
  myPort = new Serial(this, "COM6", 9600);
  myPort.bufferUntil('\n'); 
}

// Draw the Window on the computer screen
void draw(){
  
  // Fill canvas grey
  background( 100 );
    
  // Set the stroke colour to white
  stroke(255); 
  
  // Draw a circle at the mouse location
  ellipse( nX, nY, 10, 10 );

  //Draw Line from the top of the page to the bottom of the page
  //in line with the mouse.
  line(nX,0,nX,height);  
}


// Get the new mouse location and send it to the arduino
void mouseMoved(){
  nX = mouseX;
  nY = mouseY; 
  
  //map the mouse x coordinates to the LEDs on the Arduino.
  new_sX=(int)map(nX,0,800,0,10);

  if(new_sX==old_sX){
    //do nothing
  } else {
    //only send values to the Arduino when the new X coordinates are different.
    old_sX = new_sX;
    myPort.write(""+new_sX);
  }
}

Light-based communication seems to wind throughout the MIT Media Lab -- it is a universal language, after all, since many devices output light, be it with a dedicated LED or a standard LCD, and have the capacity to view and interpret it. One such device, coined Droplet, essentially redirects light from one source to another, while also serving as a physical interface for tablet-based tasks. Rob Hemsley, a research assistant at the Media Lab, was on hand to demonstrate two of his projects. Droplet is a compact self-contained module with an integrated RGB LED, a photodiode and a CR1216 lithium coin battery -- which provides roughly one day of power in the gadget's current early prototype status. Today's demo used a computer-connected HDTV and a capacitive-touch-enabled tablet. Using the TV to pull up a custom Google Calendar module, Hemsley held the Droplet up to a defined area on the display, which then output a series of colors, transmitting data to the module. Then, that data was pushed to a tablet after placing the Droplet on the display, pulling up the same calendar appointment and providing a physical interface for adjusting the date and time, which is retained in the cloud and the module itself, which also outputs pulsing light as it counts down to the appointment time.

StackAR, the second project, functions in much the same way, but instead of outputting a countdown indicator, it displays schematics for a LilyPad Arduino when placed on the tablet, identifying connectors based on a pre-selected program. The capacitive display can recognize orientation, letting you drop the controller in any position throughout the surface, then outputting a map to match. Like the Droplet, StackAR can also recognize light input, even letting you program the Arduino directly from the tablet by outputting light, effectively simplifying the interface creation process even further. You can also add software control to the board, which will work in conjunction with the hardware, bringing universal control interfaces to the otherwise space-limited Arduino. Both projects appear to have incredible potential, but they're clearly not ready for production just yet. For now, you can get a better feel for Droplet and StackAR in our hands-on video just past the break.

Gallery: MIT Media Lab: Droplet and StackAR hands-on

Continue reading Droplet and StackAR bring physical interface to virtual experiences, communicate through light (hands-on)

Droplet and StackAR bring physical interface to virtual experiences, communicate through light (hands-on) originally appeared on Engadget on Tue, 24 Apr 2012 15:03:00 EST. Please see our terms for use of feeds.