Better 3D Prints By Mixing Slicing Techniques

July 22, 2015 by Al Williams 28 Comments

Most 3D printing projects start with a 3D model of some kind. Slicing programs transform the model into gcode. The gcode file contains the commands that actually drive your printer. There are different ways to slice a model and sometimes you want to use more than one on a single model. I’ve been working on a way to make that easier.

When you slice a 3D printing model, you can select different attributes for the resulting gcode file. For example, you might set the slicer to produce different infill density, temperatures, or print speeds. These settings can have a big impact on your printing results. For example, a piece that needs high strength might require a denser infill than some trinket or key chain. You might want an artistic piece to have a finer layer height than some internal part for some gadget no one will ever see.

One Size Fits All?

The problem is that for most open source slicers, these settings will apply to the entire model. Cura has some plugins that can change settings at different Z heights, and Slic3r can vary layer height, but in the general case, what you set for the slicer will apply to the entire model. Of course, a gcode file is nothing more than a text file, so if you are industrious, you can manually merge two or more files into one.

A manual merge is a pain, which is why I wrote gblend. It can stitch together gcode files to get various effects. The program takes multiple gcode files in as inputs and can combine them in different ways. The most useful feature allows you to get a certain number of layers from each source file and combine them into a single print. Measurements are in millimeters, so you don’t have to worry about layer numbers. The entire process is much easier than anything else I’ve come across.

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Learn FPGAs In Your Browser

July 21, 2015 by Al Williams 40 Comments

FPGAs aren’t really programmed, they are configured. Most designers use Verilog or VHDL to describe the desired circuit configuration. Developers typically simulate these configurations before committing them to silicon (a good habit, especially if you ever graduate from FPGAs to ASICs where changes are very expensive). That simulation takes a lot of software you have to install and learn, right?

Not necessarily. You can do e-mail, word processing, and PCB layout in your browser. Why not FPGA design? The EDAPlayground website provides two editor views: one for your main “code” and another for the testbench (the simulation driver you use to test your design). You can even open multiple files, if you have a complex design.

Once you’ve entered your Verilog or VHDL (or picked one of many examples) you can run the simulation and see the result right in your browser. No software to install, and–outside of actually learning VHDL or Verilog–not much learning curve.

As [Strauburn], [combinatorylogic], and others commented on our recent post about a VHDL CPU, you can do a lot of learning without ever having your hands on real hardware. The web site gives you access to several different tools (useful if you want to see how your code will behave on different tools) and also many standard verification libraries. There are limited synthesis tools, but honestly, if you want to go to real hardware, you are going to want the vendor tools for the specific FPGA you are using.

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A Breadboard In A Browser

July 20, 2015 by Al Williams 16 Comments

[Flownez] sent in a tip that a port of the venerable Falstad circuit simulator is now available that doesn’t require Java (it uses HTML 5). This is a welcome port since some modern browsers (particularly Chrome) make it difficult to run Java applets and prevented the Falstad simulator’s execution.

Like the original simulator, this one is great to show a classroom circuits and encourage building or studying circuits in the browser. There’s no extra software to install, which is handy for an impromptu demo. Another cool feature is the visualization of current flow as animated dots. The dots move in the direction of the current flow and the speed of motion is proportional to the amount of current. Watching a capacitor charge with the moving dots is very illustrative. You can also view data in a scope format or hover the mouse over things to read their values.

You can open a blank circuit and add quite a few components (use the right click button on your mouse or the menu to add components and wires). However, you can also pick from a number of predefined circuits ranging from the simple (a voltage divider, for example) to the illustrative (a PLL frequency doubler comes to mind). There’s even an AM radio (see below) that you can tune to find several “stations” by varying the tuning capacitor’s value. Circuit elements include many types of analog and digital components.

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Police LiDAR Tear Down

July 20, 2015 by Al Williams 48 Comments

Most police departments made a big switch from RADAR to LiDAR after consumers starting buying RADAR detectors. A lot of those LiDAR units are now out there on the surplus market. If you don’t have $500 or so to buy a LiDAR gun just to see what makes it tick, you are in luck. [Alexei Polkhanov] spent an hour tearing down a UltraLyte LTI 20-20 LR 100 so you don’t have to.

An hour seems like a lot for a tear down video, but [Alexei] speeds up through the boring parts, and spends a lot of time talking about the optics and how the device works (with a lot of hand drawn diagrams). He also puts it back together and connects a scope to show the electronic operation of the device.

He mentions the display and control board uses a serial interface to talk to the controller board. There is also an unpopulated header on the main board that is clearly a serial port, probably for reprogramming the onboard microcontroller. With a little reverse engineering work, this LiDAR gun ought to be highly hackable.

In addition to the display and control board, the unit contains a high voltage supply for the laser and the photodiode. Making a power supply to drive the laser that is clean enough not to disturb the sensor is one of the design drivers and it shows. The power supply is a large and complex board by comparison to the other boards in the system.

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Talk To The (Robotic) Hand

July 19, 2015 by Al Williams 1 Comment

Robotic hacker [Andrea Trufini] apparently likes choices. Not only does his robotic arm have six degrees of freedom, but it has a variety of ways he can control it. The arm’s software can accept commands through a programming language, via potentiometers, an infrared remote, or–the really interesting part–through spoken commands.

The videos don’t show too much of the build detail, but the arm is mainly constructed of laser cut plywood and uses an Arduino. Hopefully, we’ll see more particulars about the build soon but for now have a look at a similar project.

The software (myrobotlab) is on github and looks very impressive. The Java-based framework has a service-oriented architecture, with modules that support common processors (like the Arduino, Raspberry Pi, and Beagle Board) along with I/O devices (like motors, sound devices, and that Leap Motion controller you just had to buy). As you might expect from the demonstration found below, there are speech to text and text to speech services, too. Like a lot of open source projects, some of these services are more ready for prime time than others but that just means you can contribute your hacks back to the project.

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The Internet Of Soldering Irons

July 19, 2015 by Al Williams 25 Comments

The Internet of Things needs — well — things. Do you really need your paper shredder hooked up to the Internet? Maybe. But [Vegard Paulsen] put something on the network that every hacker can relate to: his soldering iron.

In typical hacker fashion, fixing a broken digital display on the soldering station turned into a development project that allows [Vegard] to monitor the temperature of his soldering iron on his phone. He found a handy source of power on the station’s PC board and connected a NodeMCU WiFi device (that uses the ubiquitous ESP8266 and an onboard Lua interpreter).

The data pushes out to the Thingspeak server which handles pushing data out to the bigger network, and data representation (like the cool Google gauge in the picture). The best part: [Vegard] gets a phone notification when he accidentally leaves his soldering iron on. How perfect is that?

One unique challenge he faced was soldering the power wires to the soldering station. This could be a problem because the iron tip is grounded so making the joint while the iron was energized would probably blow a fuse (or worse). Luckily, [Vegard] thought ahead and devised a plan that apparently worked.

We’ve seen other examples of how easy NodeMCU and Thingspeak work to put the mundane on the Internet. It seems particularly appropriate to hack a soldering iron, though.

Secret Keyboard Stash

July 18, 2015 by Al Williams 32 Comments

Hide in plain sight is an old axiom, and one that [Kipkay] took to heart. His sneaky keyboard hack takes the little-used numeric keyboard and converts it to a handy (and secret) hiding hole for small objects you want to keep away from prying eyes.

You might have to adapt the hack to your specific model, but [Kipkay] cuts out the membrane keyboard, secures the numeric keypad keys with hot glue, and then cuts it out with a Dremel. Some cardboard makes the compartment and once the fake keypad is in place, no one is the wiser.

As you can see in the clip after the break, the compartment isn’t very big. You aren’t going to hide your phone inside, but it is just the right size for some emergency cash, a credit card, or maybe an SD card or two.

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