A little MDF, a little plywood, some bits of threaded rod – put it all together and you’ve got this low-cost desktop CNC build using very few parts you’d need to go farther afield than the local home center to procure.

We’ve seen lots of e-waste and dumpster diving CNC builds here before; what’s appealing here is not only the low price tag of the build but also its approachability. As the short videos below show, [Thimo Voorwinden] does an admirable job of using the tools and materials he has on hand. We also appreciate the modularity of the build – the X- and Y-axis carriages are nearly identical and could be interchanged to alter the dimensions of the work area, or even replaced with a larger carriage if needed. The Z-axis is a little different from the usual low-end CNC build in that it doesn’t use a Dremel or other small rotary tool but rather mounts the handpiece of a flexible shaft rotary tool. Keeping the motor off the machine allows for more torque, less vibration, and reduced dead load.

The end result is a desktop CNC for about €200 with a work area large enough to fabricate small wooden and plastic parts, or to mill foam blocks for use as casting molds. It looks like [Thimo] has more in store for his little CNC machine, and we’re looking forward to seeing what improvements he can come up with.

[ via r/CNC]

You’d think that with as many sick people as there are in the world, it wouldn’t be too difficult for a doctor in training to get practice. It’s easy to get experience treating common complaints like colds and the flu, but it might take the young doctor a while to run across a dissecting abdominal aortic aneurysm, and that won’t be the time for on the job training.

Enter the SP, or standardized patient – people trained to deliver information to medical students to simulate a particular case. There’s a problem with SPs, though. While it’s easy enough to coach someone to deliver an oral history reflecting a medical condition, the student eventually needs to examine the SP, which will reveal none of the signs and symptoms associated with the simulated case. To remedy this, [Chris Sanders] and [J Scott Christianson] from the University of Missouri developed an open-source RFID stethoscope to simulate patient findings.

This is one of those “why didn’t I think of that?” ideas. A cheap stethoscope is fitted with an Arduino, and RFID reader, and a small audio board. RFID tags are placed at diagnostic points over an SP’s chest and abdomen. When the stethoscope is placed over a tag, a specific sound file is fetched from an SD card and played over earbuds. The student doesn’t have to ask, “What am I hearing?” anymore – the actual sound of bruits or borborygmi are heard.

We can easily see expanding this system – RFID tags that trigger a faux ultrasound machine to display diagnostic images, or tiny OLED screens displaying tagged images into an otoscope. A good place to start expanding this idea might be this digital stethoscope recorder and analyzer.

We’ve seen a lot of interest in LSM (LASER Scanning Microscopes) lately. [Stoppi71] uses an Arduino, a CD drive, and–of all things–two speakers in his build. The speakers are used to move the sample by very small amounts.

The speakers create motion in the X and Y axis depending on the voltage fed to them via a digital analog converter. [Stoppi71] claims this technique can produce motion in the micron range. His results seem to prove that out. You can see a video about the device, below.

Oddly enough, [Stoppi71] found that older CD drives were easier to work with because they were not as miniaturized as more modern versions. The device uses the Arduino to drive the scanning table (the speakers), and read the photodetector. The results of the scan appear on an LCD screen.

Using a calibration slide from eBay, [Stoppi71] calibrated the device for different magnifications. You can see the test slide at medium magnification. For the record, a human hair is about 40 or 50 microns thick. So the 10 micron mark in the photo would be like splitting a hair in quarters or fifths.

The real goal was to view pits on CDs, and the instrument is more than capable of doing that. The image doesn’t show up all at once (it is scanning, after all) and it isn’t the kind of view you’d expect from an optical microscope, but a typical optical scope can’t resolve below about 200 microns. Special techniques can push that lower, but being able to resolve things at the one or two micron level with something this simple is a great accomplishment.

We recently saw a different-looking LSM built on a conventional microscope stage and a DVD drive. If LSM isn’t enough for you, maybe you should pitch in on the open source electron microscope project.

Using an Arduino Uno with a CNC shield,  Thimo Voorwinden has made his own CNC out of MDF for just over €200 ($212).

CNC routers really open up what the type of item you can make, but tend to be expensive. Voorwinden’s homemade version, however, features a work area of 200mm x 250mm x 100mm. As shown in the results video below, it’s accurate enough to cut two pieces of MDF so that they can nest securely inside of one another. Impressively, the whole assembly was created using basic tools.

Two interesting features on this build are that the workpiece is fastened down with wood screws into the Y-axis gantry, and that it employs an offset motor with a flexible shaft to transfer power to the cutting head. 12 bearing blocks and 8mm diameter steel rod are used to keep everything lined up.

You can see more of this project in Voorwinden’s write-up, including several other videos as well.

In what is perhaps the most Arduino boards used together, 130 Arduino Nanos, (plus an Arduino Mega), 130 RFID readers, and 750 RGB LEDs power this interactive crossword puzzle.

As you might suspect, bringing a giant crossword puzzle to life was lot of work. If you’d like to know how much, you can see the process laid out in the video below. Like many great hacks, this project starts out with a lot of prep, making sure the mechanical pieces go together as they should. Everything is then wired and programmed, and on day six, it finally goes out the door, destined for the National Museum in Warsaw, Poland.

Each letter has an RFID tag. Under the table are custom made circuits with Arduino Nano, RFID reader, and WS2812B. There is 130 of those circuits and the are connected by I2C interface together to Arduino Mega 2560, which is the main brain. So basically, the table recognizes letters and takes proper actions.

• When there is no letter: LED are dimmed white
• When letter is good: LED are green
• When letter is bad: LED are red
• When whole word is completed: LED play colorful animation

The main controller (Arduino Mega) communicates with a PC via RS-232. This PC plays special graphic visualization on the wall. When the whole crossword is completed, the whole table begins doing disco + sound effects.

It’s quite a colorful display, and it looks like the kids playing with it in the “Anything Goes” exhibition love it! You can see more about this project in Robert Mordzon’s write-up.

For the fourth year, we invite the open source community to join us in celebrating Arduino’s birthday on Saturday, April 1st!

Arduino Day is a 24-hour-long worldwide event – organized by our team and the community – where people interested in Arduino can get together, share their experiences, and learn more about the platform through all sorts of activities, tailored to local audiences. Participation is open to anyone, from young Makers and students to professional engineers and designers.

More than 330 were held by Arduino enthusiasts across the globe in 2016. This year, we are hoping to make that number 500! If you want to organize Arduino Day festivities of your own, please fill out the online form and submit your proposal here by March 11th.

In the coming weeks, be sure to visit the official website to learn more or find an event in your area. And don’t forget to post, engage, and follow along on social media using the hashtag #ArduinoD17!

There have been a lot of smart computers on TV and movies. We often think among the smartest, though, are the ones on Star Trek. Not the big “library computer” and not the little silver portable computers. No, the smart computers on Star Trek ran the doors. If you ever watch, the doors seem to know the difference between someone walking towards it, versus someone flying towards it in the middle of a fist fight. It also seems to know when more people are en route to the door.

Granted, the reason they are so smart is that the doors really have a human operating them. For the real fan, though, you can buy a little gadget that looks like an intercom panel from the Enterprise. That would be cool enough, but this one has sound effects and can sense when someone walks into your doorway so they can hear the comforting woosh of a turbolift door.

Of course, for the real hacker, that’s not good enough either. [Evan] started with this $25 gadget, but wanted to control it with an Arduino for inclusion in his hackerspace’s pneumatic door system. He did a bit of reverse engineering, a bit of coding, and he wound up in complete control of the device.

The internals of the device were mostly straightforward with some PIR sensors, switches, LEDs, and some epoxy blobs that produce the sound and control the logic. [Evan] had to be a little creative since the red alert sound, once started, would not stop for some time. The solution? Let the Arduino cut power to the board when it wants silence.

The code is available on GitHub. There were a few other tricks required, including removing a PIR sensor chip and adding a USB to serial adapter. Once you can treat the whole thing as an I/O device, you could probably do a lot of interesting projects easily. And of course, this sort of offering would be perfect as an entry in the Hackaday Sci-Fi contest.

For some reason, we don’t see as many original series hacks as we do for the Next Generation. We have, though, seen at least one other swoosh door. On the other hand, if you fly against that door while being thrown by a Captain Kirk style body slam the door will still open. We can’t vouch for it, but this video has an interesting analysis of the door noise that reminded us of a modern version of playing our old LPs backward.

Give kids some responsible and challenging tasks, and you’d be surprised at the results. The “Anything Goes” exhibit at the National Museum in Warsaw was aimed as a museological and educational experiment. A group of 69 children aged 6–14 was divided into teams responsible for preparing the main temporary exhibition at the museum. Over six months, they worked on preparing the exhibition during weekly four-hour meetings. They prepared scripts, provided ideas for multimedia presentations, and curated almost 300 works for display. One of those was [Robert Mordzon]’s Giant Interactive Crossword.

The build is in two parts. The letter tiles, which have embedded RFID tags, obviously look like the easiest part of the build. The table, looking at the video (after the break), probably needed a lot more effort and labour. It is built in two halves to make construction easier. There are a 130 boxes that need to be filled in with the right letters to complete the crossword. Each box contains a bunch of electronics consisting of an Arduino Nano, a RFID Reader and a bunch of sixteen WS2812B LEDs, all assembled on a custom PCB. Do the math, and you’ll figure out that there’s 2080 LEDs, each capable of sipping 60 mA at full brightness. That’s a total current requirement of almost 125 amps at 5 V. Add in all the Arduino’s, and [Robert] needed a beefy 750 W of power, supplied via four switch mode power supplies.

Each Arduino Nano is a slave on the I²C bus. The I²C master is an Arduino Mega 2560, which in turn communicates with a computer over serial. When a box is empty, the LEDs are dim, when a wrong letter is placed, they turn Red, and when the right letter is placed, they turn Green. If a word gets completed, a special word animation is played. This information is also passed on to the computer, which then projects an animation related to the word on a giant wall screen. Upon the crossword getting completed, the table erupts in to a sound (via the computer) and light “disco” show and also reveals the main motto of this section of the exhibit – “Playing the Hero”.

When your microwave is done with its food, it generally beeps… and beeps… and beeps. Though you definitely want to know when your frozen burrito is edible, if you get to it right when it wants, things can get quite annoying. Tim Gremalm decided to do something about it, and replaced the buzzer in his appliance with an Arduino Nano, an amplifier, and small speaker.

His initial speaker/amplifier combination wasn’t loud enough so he replaced it with more appropriate options. After this hack, he now has something that can play a more pleasing tone—in his case, the Windows XP startup sound—and do so only once!

You can see more of this project on Gremalm’s page, as well as check out his code here or this Arduino program that inspired his code. It’s a neat hack, and a great example of what can be done with an Arduino, but you probably shouldn’t mod your microwave unless you really know what you’re doing!

Voroni moves in a smooth and organic way, thanks to some creative thinking.

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