Arduino H bridge

 (Click to enlarge)

(and if you right click and choose 'view in new tab' on chrome you can see the full sized photo)
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiqy6vY0Bx1qBW_bQjpqGSyrlwPGYUJqlqQFw0muAWKM8goXgNnAfPXRU2mwgM2KKXW0qJ1eXIfOKIKy9inZwOTyavKZSdj53_ZKBdVcc8N1owjB2Nyuy0FwtTTsN4XuTT4RdxAzShmu8s/s1600/Hbridge.jpg

Just some personal notes on an Arduino H-Bridge.
http://ikalogic.cluster006.ovh.net/bjt-switches/

My Zbrush art

Just a little 3d artwork of mine, so that you know i am more than math and science. :)

Servo Test

A servo test of a robot built using AS3 glue, flash and an Arduino Uno.

(click to enlarge)

Some notes, the board only supports up to two servos and so does flash glue. You can by changing some of the programming get the AS3 glue to support as many servos as you want but you have to power them separately (i used a simple radioshack voltage regulator and a nine volt battery.) also you should multiplex the movements so that the servos are accurate. otherwise you get a lot of analog noise and the servos are not that precise. to multiplex in flash action script i did something like the following:

var speed:Number = 500;

setInterval (move, speed, 9, 10);

setInterval (move, speed*2, 10, 145);

function move (Pin:Number, Rotation:Number):Void

{

a.writeAnalog(Pin,Rotation);

}

Arduino robotic arm.

Using flash and AS3. Tutorial to come.. .maybe?

photogrammetry

So I would like to begin our discussion about motion capture by explaining to you how exactly photogrammetry works. While you may not feel like it's all that important and you just want to know how i built my DIY facial motion capture rig, I guarantee that it is important to know how it works so that you can problem solve the rig and create solutions on the fly. Also you wont be tied down to my rig and software and you may (most likely) create something superior to my set up. I will also be presenting more than one rig and i want you to understand them.

Lets begin with the math and how exactly an optical camera can tell the 3D location of an object.
There are two very simple geometric facts that you need to know.
1)all of the angles of a triangle add up to 180 degrees. So A+B+C ALWAYS equal 180.

2) the sine rule

It's a good start and luckily all the math you will every need for motion capture (well not really...but it's all you'll need for these rigs.)

Lets start by imagining you have a single camera that sees an object in the distance.

Then the camera moves around the scene creating a triangle.

So now we know that the camera moved ten feet and we can figure out the objects location in 3D space.

Ok Great so now we know that the angle C is 105 °. 

Now let us find the lengths of the side and locate the object in 3d space. We know the camera moved 10 feet. we also know the sine rule.

So there you have it we have deduced exactly where a point is in space with only the angle and a camera move. This is (simplistically) exactly how match moving programs work. 

 and here is our completed triangle:

Hope you enjoyed it, I know math can be frustrating. In my next post we will get down to some of the fun stuff and actually start designing our mocap rig.

Arduino LUX sensor

Arduino LUX sensor.

(click to enlarge)

Code:

/*
  LiquidCrystal Library - Hello World

 Demonstrates the use a 16x2 LCD display.  The LiquidCrystal
 library works with all LCD displays that are compatible with the
 Hitachi HD44780 driver. There are many of them out there, and you
 can usually tell them by the 16-pin interface.

 This sketch prints "Hello World!" to the LCD
 and shows the time.

  The circuit:
 * LCD RS pin to digital pin 12
 * LCD Enable pin to digital pin 11
 * LCD D4 pin to digital pin 5
 * LCD D5 pin to digital pin 4
 * LCD D6 pin to digital pin 3
 * LCD D7 pin to digital pin 2
 * LCD R/W pin to ground
 * 10K resistor:
 * ends to +5V and ground
 * wiper to LCD VO pin (pin 3)

 Library originally added 18 Apr 2008
 by David A. Mellis
 library modified 5 Jul 2009
 by Limor Fried (http://www.ladyada.net)
 example added 9 Jul 2009
 by Tom Igoe
 modified 22 Nov 2010
 by Tom Igoe

 some of this example code is in the public domain.
 http://www.arduino.cc/en/Tutorial/LiquidCrystal

 modified 5 Aug 2012
 by Christopher Vaughan
 */
// include the library code:
#include <LiquidCrystal.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
void setup() {
 
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
   
}
void loop() {
  //Get photoresitor value
    int sensorValue = analogRead(A0);
  //remap the value to LUX
    int lum = map(sensorValue, 0, 1023, 0, 110);
  // reverse value so that dark is 0;
    int lum2 = 110 - lum;
  // set the cursor to column 0, line 0
   lcd.setCursor(0, 0);
    String stringOne = " LUX       ";
  String stringThree = lum2 + stringOne;
 
   lcd.print(stringThree);
 // set the cursor to column 0, line 0
  // (note: line 1 is the second row, since counting begins with 0):
  lcd.setCursor(0, 1);
  // print the number of seconds since reset:
  lcd.print(millis()/1000);
}

Classical Physics - vectors part 3