Category: Uncategorized

It seemed like a simple enough request… While at Milwaukee Makerspace we were discussing creating snowflakes on the Laser Cutter, and I mentioned that there should be some existing art on OpenClipArt.org, but it was down that night, so I jumped over to Thingiverse and found this snowflake.

As a bit of background, I’ve been pretty damn good at file conversions in the past. Audio, video, markup, raster images, anything 2D has been pretty simple. I mean, I’ve been using Photoshop since version 1.0.7. I know how to deal with that stuff… but 3D? It’s a whole new ~~nightmare~~ world!

Snowflake

The file was an STL, which is meant for 3D printing, but we needed more of a 2D vector file. I know how to load a DXF file into the Laser Cutter, so I figured I’m import this STL into Google Sketchup (via a plugin) and then export as a DXF (via another plugin) and that would be it.

Well, that didn’t work. (Oh, and by “didn’t work” I mean I was unable to open the DXF file in Inkscape. At this point I was still waiting to use the Laser Cutter so I didn’t get to try importing it on that machine. I figured that as long as I was waiting, I’d try to get a format I knew would work.) On to the next idea.

I exported the STL from Google Sketchup as a DAE file, and was able to open that in MeshLab. Once again I tried a DXF export, but that one wouldn’t open in Inkscape either. Argh!

Snowflake

So I made a radical decision… Since I could view the file in MeshLab, I just did a screen shot so I could get a nice, clean 2D version of it.

Snowflake

Of course if I had known I was going to do this, I probably could have just done it in Google Sketchup by altering the view… Still, the MeshLab method seemed solid.

Snowflake

I then took the screen shot and opened it in Photoshop, did a little editing, and converted it to black and white. (I considered creating paths, and exporting them, but at this point I wanted to go with what I knew (or thought) would work, and that meant getting a clean PNG file into Inkscape to convert it from a raster to a vector file via trace bitmap.

Snowflake

So finally, I had my SVG file! A vector file I could open in Inkscape and export as a clean DXF file that I was reasonable sure would open and work on the Laser Cutter…

Snowflake

Oh wait, at some point along the way I had created an OpenSCAD file, to test the other DXF files. They wouldn’t render due to some weirdness, but the new one I exported from Inkscape did. This made me feel a little more secure that this file would work.

So how did it turn out? I don’t know!

The Laser Cutter was in use making ornaments, and I couldn’t stay late enough to get a chance to use it.

And just to be clear… while there were many steps in the process above, the whole thing took about 20 minutes from the first file export to getting what seemed to be a good DXF file.

I’ve converted a lot of files in my time, but doing so for these CNC machine is proving to be a new challenge.

Of course half the fun is seeing if it will work, you know, on the machine… which I hope to test at some point. :)

Tags 3d, dxf, inkscape, makerspace, meshlab, openscad, photoshop, sketchup, snowflake, stl

Uncategorized

Processing PhotoBooth

You probably know I’m a fan of Photo Booths, and while Sparkbooth is awesome software, you might want something free (and open source) so here’s “PhotoBooth” written in Processing.

This is all the code you need for the most minimal photo booth application:

/**
 * PhotoBooth.pde
 */ 
 
import processing.video.*;
Capture cam;

void setup() {
  size(1280, 720);
  cam = new Capture(this, 1280, 720);
}

void draw() {
  if (cam.available() == true) {
    cam.read();
    image(cam, 0, 0);
  }
} 

void keyPressed() {
    if (key == ' ') {  // space bar
      saveFrame("picture-####.jpg");
    }
}

Once you’ve got that, you can export it as an application from Processing.

(Note that I’m using a Logitech C910 webcam, so I’ve set the resolution to something that makes sense for that camera. If it looks weird with your camera, try 640×480 or something else.)

I generally use Mac OS X, but other operating systems are supported. This is one of the great things about Processing.

Over in the Finder you’ll see a standalone application named “PhotoBooth” that will run fullscreen when launched. (You can exit it by hitting the escape key.)

Once you launch it you’ll see some spazzy dude, wait, that’s me! You’ll probably see yourself instead.

Hit the space bar, and it’ll save a photo. Hit the space bar again and it’ll save another one. And on, and on.

The photos will show up in the same folder as the application. They will have a random number in the name. It’s not sequential, but you can view by date created if you need them in order.

Here’s a more full version of the Processing code with a few extras commented out. Uncommenting them may prove useful for debugging or camera set-up.

/**
 * PhotoBooth.pde
 */ 
 
import processing.video.*;
Capture cam;

void setup() {
  size(1280, 720);

  // If no device is specified, will just use the default.
  cam = new Capture(this, 1280, 720);

  // To use another device (i.e. if the default device causes an error),  
  // list all available capture devices to the console to find your camera.
  //String[] devices = Capture.list();
  //println(devices);
  
  // Change devices[0] to the proper index for your camera.
  //cam = new Capture(this, width, height, devices[0]);

  // Opens the settings page for this capture device.
  //cam.settings();
}

void draw() {
  if (cam.available() == true) {
    cam.read();
    image(cam, 0, 0);
  }
} 

void keyPressed() {
    if (key == ' ') {  // space bar
      saveFrame("picture-####.jpg");
    }
}

And hey, I know that hitting the space bar ain’t cool… so you might want to use an awesome button instead.

This is a super-simple application, which basically takes some example code that ships with Processing and adds a bit to it. I hope to have a few more posts that talk about some changes you can make to this application. Stay tuned!

Tags button, photobooth, photos, processing

Uncategorized

The iPhone 4S Camera

Post author By Pete Prodoehl
Post date 2011-12-06

I’ve been meaning to do some iPhone 4S camera tests for a while now, and rather than wait and wait while I come up with a scientific method, I thought I’d just do a few shots and post them here. Early and Often, right?

Each photos links to the Flickr version you can view it at various sizes. None of the photos have been retouched at all.

Normal iPhone 4S photo with direct light.

HDR iPhone 4S photo with direct light.

Normal iPhone 4S photo with soft light.

HDR iPhone 4S photo with soft light.

For each shot the iPhone was on a tripod, and an overheard light consisting of a single bulb was used. (It’s a large high wattage bulb from an old photostat machine.) For the soft light shots, I put an umbrella in front of the light. I used Apple’s default Camera app that comes on the iPhone. All were shot on the white sweep I use for all my tabletop stuff. (If you’ve seen my Flickr stream, you’ve seen plenty of shots on that sweep.)

Experimental iPhone Tripod Mount

This photo of my “Experimental iPhone Tripod Mount” was taken (handheld) with my Nikon D40. If you wanted to compare the two, the iPhone 4S is supposedly an 8 Megapixel camera, while the Nikon is a 6 Megapixel camera. Size isn’t everything of course. Well, the Nikon does have a bigger lens, so that helps quite a bit. The Nikon also shoots in RAW, and yes, this shot has been edited quite a bit, but hey, that’s what I do with RAW photos. (And I mainly took this shot to show the set-up I used.)

When I get ambitious again, I’ll set up two tripods, one with the iPhone, and one with the Nikon, and do duplicate shots of various objects. Until then, enjoy these… I’m off to work on my Experimental iPhone Tripod Mount Version 2.0

Tags cameras, iphone, nikon, photos

Uncategorized

Fire the Laser!

Post author By Pete Prodoehl
Post date 2011-12-04

I finally got some quality time with the Laser Cutter at Milwaukee Makerspace, and I have to say, I’m fairly pleased with the results!

Milwaukee Makerspace Logo

I started with the Milwaukee Makerspace logo (in SVG format) in Inkscape, and exported it as a DXF file. (I also kept the stroke of the width just 1 pixel for all the lines.)

Once I had a DXF file, I was able to import that into CorelDRAW, which is what the PC that controls the Laser Cutter uses to do the work. There’s a bit of trickery in CorelDRAW between raster and vector artwork, but doing it this way with a DXF file at just one pixel wide seemed to force it to work in vector mode, which is what I wanted.

Knowing the power and speed settings for the Laser Cutter are tricky, and require a bit of experimentation based on if you are etching or cutting, and how deep you wish to etch or cut. The nice thing is, as long as you don’t move whatever your material is, you can run the Laser Cutter multiple times to go deeper, or complete a cut. In many cases this may be the way to go… (More on that later!)

It’s worth noting that some materials should NEVER be cut. Since our pals at PumpingStation: One already have a list, I’ll point you to the NEVER CUT THESE MATERIALS list on their their wiki. The also have this cool list of laser settings. (Yeah, we’re working on that as well. We have a different laser, so we need to start from scratch.)

Here’s a close-up of the etching into wood. I ran it a few times. If you’re doing a vector cut, it just traces around the outline, and goes super-fast. If you are using raster artwork, it’ll behave like an old dot-matrix printer and go line-by-line and take forever. Shane did this Periodic Table and it took almost two hours. (It does look pretty amazing though!) I’m still not 100% sure what CorelDRAW does with each format. I tried to import an SVG file but it seems to convert it to raster format. The DXF kept its vector format, so I’ll stick with that for now.

After I was satisfied with wood, I moved on to plastic. When I say plastic, I mean “plastic” and I don’t know if it’s acrylic, or plastic, or what kind of plastic, or anything else, so I’ll just leave it at that for now. (And yes, we’ve got a nice scrap pile of plastic at the Makerspace to experiment with.)

This is just an outline of the logo, but we should be able to use a filled-in logo (in raster format) and create the effect of frosted glass, and then we can do this Floating Glow Display project from Make with our laser-etched plastic. Hmmm, it looks like I just gave myself another project to tackle!

Tags inkscape, lasers, makerspace, milwaukee, plastic, tools, wood

Uncategorized

Pachube Learning

Post author By Pete Prodoehl
Post date 2011-11-29

Pachube I first heard of Pachube shortly after it launched, and took a look at it, but didn’t really have any data to feed it. Then they started charging for the service, so I never pursued it, and then they got acquired by LogMeIn, and became free again, so I figured I’d check it out.

If you’ve seem my posts about logging the temperature and humidity, then you can guess what data I started feeding into Pachube.

Take a look at the feed Environment for a constantly-updated view of my office. We’re tracking the temperature and the humidity, but I’d also like to add a photocell (light sensor) and occupancy sensor (PIR) at some point.

I dabbled in Processing code, but ended up going back to Perl after some instability. There’s still some issues with bad data I need to sort out. (See below.)

Bad Data

There’s not a lot of amazing code in place yet, as it’s all learn-as-I-go experimental, but that’s fine with me…

Pachube iPhone

I mean, as it stands right now, I can quickly see the status of my office from anywhere in the world as long as I’ve got a mobile phone and an Internet connection. That alone should be worth something…

I’ve been adding updates along the way over at the project page on the Milwaukee Makerspace wiki. I’m sure I’ll have more blog posts on this, but smaller updates will probably just show up on the wiki.

Tags arduino, data, logging, pachube, sensors