Here is a picture of the new “machine”.

Its based on an A-frame and has a hinged support on the rear so that it leans back at the desired angle.  Right now its leans at 20 degrees.  The rotating disk, which holds the paper, is four feet in diameter.  The disk rests on two rollers; one is the idler on the left and the motor drive roller on the right.  The disk leans on three casters behind the disk.  Gravity keeps it in place.  This keeps things simple and not overly constrained.  There is no central shaft so the disk center is determined by the two rollers.  I used a router with a 24 inch arm which allowed me to cut a very precise circle.

So far it looks like it will work, it rotates very smoothly.  Driving on the edge insures that there is no backlash with the big disk and provides a 32:1 reduction from the motor.  The NEMA 34 motor has no trouble driving the disk.  The controller in the picture is just being used to test the design.

Next is the two 24″ disks which will be mounted above the 48 inch disk.   As in my earlier machine the pen arms will connect to the smaller disks with a movable magnet with a short shaft.  The two disks will make the whole thing look like a familiar mouse character.

This new design is meant to be suited to display in a gallery or other situation so more people can watch it work.

I have new motor controllers on order.  I hope to have it working for the East Austin Studio Tour in November.  We’ll see.

I was pleased to be invited to take part in the TEDx Austin event on February 9th at the Circuit if the Americas. I produced an interactive video and sound piece for the event called “Sound of Shadows”

The installation used Processing 2 running under Ubuntu 12.04 on a Quad-Core desktop computer.

A Creative HD webcam captured the image from a retrto-reflective screen to obtain a high contrast shadow of a person interacting with the piece.  The program then traced a horizontal outline of the person then scanned it at 150 beats per minute to play musical notes based on the persons outline.

As the videos show, guests got the hang of it quickly and had fun manipulating both the imagery and the sound.

I’ll be continuing to work on the piece to both enhance the images and the sound.

Thanks to Brent Dixon for inviting me and putting together a great interactive space at TEDx.

I will be presenting a new version of this piece at the Austin Mini Maker fair in May.

This video shows people interacting with the installation.

The program grabbed a frame on every scan and saved it.  This video shows all 1400 + frames.

If you were there, you might be able to find your picture!

Sorry about the frenetic nature of this video.   The sound is based on a random walk on a c-major scale.

A long time ago, I had an IMSAI 8080 that I built from a kit.  I was working on laser shows at the time and was experimenting with a hand built DAC board for the 8080.  I saw this article in BYTE Magazine called Serindipitous Circles.  The algorithm was real simple but produced some interesting patterns that could be displayed on an oscilloscope.  Graphics displays were hard to come by at the time.

I noticed that the Auduino Due had two built-in DACs, so this was the perfect thing to try on the Due!

The article can be seen here.

I made a quick video with my cell phone.

Here’s the code:

/* Serendipitous circles algorithm from
Byte magazine February 1977
By Craig Newswanger
*/
// Variables
int x,y,xnew,ynew,j;

void setup() {
analogWriteResolution(12);
}
void loop()
{
x=random(32768);
y=random(32768);
for (j=0;j<80000;j++)
{
analogWrite(DAC0,x);
analogWrite(DAC1,y);
xnew=x-y/2;
ynew=y+xnew/2;
x=xnew;
y=ynew;
}
}

Sorry I did not spell this out clearly!
I can build boards to order.
Prices are the same as before as shown here.

Cheers,

Craig

Wow, two in a row!  Now I’m tired.

Thanks to Joe DiPrima of ArcAttack who invited me to join them in San Mateo for the mother ship of Maker events.  I set up the Drawing machine, now named the Lissagraph, after Jules Antoine Lissajous.  Many people asked what it was called, now it has a name.

Had a great time, though I saw little of the rest of the fair.  Adam Savage gave a great talk and we experienced a solar eclipse to boot!

I was located in the ArcAttack backstage area. Thanks to everyone who came by my table to talk and watch the machine.  After my the guys get back to Austin with my stuff,  I’ll be putting up a gallery of lots of the drawings so I can make it possible for those interested to purchase the images through PayPal.  Each one is unique so as they are sold, (if they are sold)  I will remove them from the gallery.

An odd pattern appears

As I was setting up the machine for a visitor, late on Sunday, an odd pattern appeared.  I was really surprised by it.  Hard to believe that this is created with sine waves.

Now I have to figure out how to recreate it.  I wrote down the rough recipe but it will take some work to figure out the starting phase.

I always come back from the Maker Faire with inspiration,  I hope it comes to something.  We’ll see!

Cheers,

Craig

The Austin Mini Maker Faire was a great success!

Great crowds.  We brought the stepper controlled drawing machine and produce lots of drawings.

People seem to be mesmerized by the drawing machine.  Round and round and round and round… your eyelids are getting heavy…

Here are a couple of photos from the event.  I put up a link to a video soon.

Thanks to Kami Wilt for organizing a great first Austin Mini Maker Faire!