A Laser Cutter Challenge

When the Louisville hackerspace LVL1 was discussing the purchase of a new laser cutter, a member said, “I could build one before you get around to buying one.”  The gauntlet was thrown down, a challenge was set, and the race was on to build a tiny laser cutter before the hackerspace took delivery of their new laser cutter.

The mechanical aspect of the build is fairly simple. The X axis is simply a stepper motor, threaded rod and laser module mounted on a carriage. This carriage moves along the Y axis with the help of two stepper motors for either side. Everything was mounted on more perfboard than reason would suggest.

For the electronics of the project, three motor drivers were made with a few logic chips and the laser firing relay was stolen from test equipment developed for LVL1’s trans-Atlantic balloon build. Motor and laser control was handled by an Arduino to keep the build simple because the contest was over after the first laser was finished cutting a square.

LVL1 is now working on a second version of the winner of the laser cutter challenge. They’re planning on a touchscreen interface that will cut a plastic blank about the size of a credit card. We can’t wait to see the results of that build.

Motion Detecting Window Closers Keep Train Noise At Bay

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[Ed Rogers] has the unfortunate privilege of living right next to a set of train tracks, and as a man who holds his sleep in high regard, he needed to find a way to keep the noise in his bedroom to a minimum. To combat the sound of passing trains, he built himself a system that automatically closes his windows when a train passes by his apartment.

The setup relies on a web cam, which uses motion-sensing software to detect a passing train. The video is analyzed by a computer in his room which passes a message to an Arduino when a train is near. The Arduino then sends a pair of window mounted linear actuators into action, slowly (and quietly) shutting his windows.

The linear actuators move pretty slowly as you can see in the video below, but we doubt that matters. Since it looks like [Ed] lives in a slow zone, it likely takes quite a bit of time for a freight train to pass, making the 40-second closing period more than reasonable.

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Get The Lead Out Of The Arduino Compile Process

Relief is here from long compile times when developing firmware for your Arduino project. [Paul] was puzzled by the fact that every file used in a sketch is fully recompiled every time you hit upload–even if that file didn’t change. To make things more confusing, this behavior isn’t consistent across all Arduino compatible hardware. The Teensy has an additional feature not seen when working with other hardware boards in that it reuses previously compiled code if nothing has changed. It even tells you which files are being reused, as shown in the image above.

After the break we’ve embedded [Paul’s] video that walks us through the process of editing the Arduino IDE to reuse previously compiled files. It’s a one-liner addition to the boards.txt file. For example, if you’re working with the Arduino Uno all that needs to be added is ‘uno.build.dependency=true’. [Paul] had previously submitted a patch to roll this into the Arduino IDE source code, but it was not accepted citing a need for more testing. He’s asking for help with that testing and wants you to post your thoughts, or any bug information, on the new issue he’s opened regarding this feature. Continue reading “Get The Lead Out Of The Arduino Compile Process”

Android Phone Serves As Arduino Terminal

Looking to use his Arduino when on-the-go, [Oleg] has been working on a way to use the Android ADK terminal emulator with the Arduino. The Android side uses ADK features along with a custom application. [Oleg] received help from his friend [Victor] when developing the program for Android (you can check out our own Android Development tutorials if you’re interested in learning how this is done). The .apk file is available for download, but they’re waiting to release the source code until they can clean it up and get some of the gnarly bugs out of the beta version.

A USB host shield for the Arduino is needed to connect to an Android hand set. You’ll be able to send and receive strings via the terminal, with support for carriage return and life feed characters. Unfortunately this doesn’t allow you to change, compile, or write sketches to the Arduino. But it might come in very handy when trouble shooting a project when a computer is not around, or just for using an Android phone as an output.

Upload Firmware Over Ethernet

The team at Wicked Device has been working on working on a way to upload Arduino sketches over Ethernet for the Nanode and Arduino Ethernet boards. The team has gotten far enough along to show the world, and the new boot loader shows a lot of promise.

A new boot loader was needed to perform this magic. The boot loader sets up a TFTP with a server over DHCP or a static IP. An unmodified .hex file is downloaded from the server and the sketch starts up. The team is still working on a way to push new apps to the board over Ethernet, but that feature is expected to be completed sometime soon.

Booting over Ethernet isn’t a new idea – TFTP was proposed for this very purpose. Because Wicked Device’s Ethernet-enabled boot loader only works over a local connection and requires a press of the reset button, it should be considered an alpha build. That being said, the boot loader works as advertised, so check out the demo video after the break.

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Portable Power Strip Control Lights And Appliances Using SMS

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[Julian] wanted a way to remotely control various appliances and lights around his house without spending an arm and a leg on home automation. He also desired the ability to easily switch what items he was controlling without a ton of hassle. Since he couldn’t find anything reasonably priced to do what he desired, he built his own SMS-triggered remote control system.

He designed his system to be used like an extension cord, hence the portable junction box enclosure. This enables him to regulate up to four different items at a time, with the ability to swap out components or relocate his controller at will.

The power strip is controlled by an Arduino which receives commands from his PC via an Xbee module. Any text messages sent to his Gmail account are retrieved by his computer and then transmitted to the Arduino. The Arduino in turn triggers relays as designated by [Julain’s] text messages, utilizing H-bridges to provide the required current.

Check out his schematics and code if you’re interested in implementing something similar in your home.

ATTiny Hacks: Run Your Arduino Project On An ATTiny!

Yup. We have all been there. You throw together a really elaborate Arduino project that only really needs a couple pins, far fewer than the Arduino’s native microcontrollers have to offer. Well fear not, [Thatcher] has solved just this problem by adding some ATTtiny cores to the Arduino IDE. His blog details the process from grabbing the MIT developed core files and loading them up in your Arduino software directories. The modification looks simple and although [Thatcher] shows the whole process on a Mac it only involves unzipping and tossing files into a folder. With ATTiny chips only a few bucks each this is perfect for those simple software driven hacks that don’t require an entire Uno duct taped to the outside of an enclosure.  Nice work [Thatcher]!