While the STAR, or Sprawl Turned Autonomous Robot, is more than capable of traveling over obstacles with its three-pointed wheels, it can also make itself thin enough to simply slide under others as needed. This clever design uses an Arduino Pro Mini for control, and normally moves around like a tank, rolling on six wheels that are turned by two motors.

When the task calls for it to go under something, a third motor cranks these wheels to nearly parallel with the floor, shrinking the robot down to a very slim profile—so thin, in fact, that it can actually slide under a door as seen in the video below! 

Print files and more information on the build can be found here, while the original paper upon which this robot is based is also available.

Father’s Day 2018 has come and gone, but it’s never too early to start planning for next year. As seen here, Michael Teeuw decided to build a clock out of three analog voltmeters for his dad in 2017. After getting sidetracked last year, he was finally able to complete it on time for 2018!

Teeuw’s clock features a trio of indicators, properly scaled and labeled for hours, minutes, and seconds, with control via an Arduino Nano, along with an RTC module for accurate timekeeping. Each indicator is housed in its own 3D-printed module, with white LEDs added for visibility. 

If you’d like to build your own, Teeuw’s code is available on GitHub and the 3D print files can be found on Thingiverse.

Solar panels are a great way to produce power literally out of thin air, but how much power they produce depends, in part, on how they are aimed. In order to figure out just how much better his solar setup could be with active tracking, YouTuber GreatScott! decided to test this by creating a miniature solar tracking system.

His device uses four LDRs to feed position data to an Arduino Nano, which then moves the small panel to properly face the sun.

The tracker/panel was set up next to a non-moving panel lying flat on his roof, and after a 2 ½-hour test, he found that the moving configuration generated 15% more energy. Of course there are other factors to consider, including time of day and how much power the tracker itself consumes, so be sure to see the experimental project and his thoughts on the results below.

Binary clocks, which use a series of dots to indicate the time, are nothing new, but you’ve never seen anything like this device by Matt Wos! 

Wos’ project features a beautiful driftwood base, and WS2812B RGB LED dots that are suspended above it with copper wire to show the time.

Inside are a pair of Arduino Nanos used to control the LEDs and take input from a small infrared remote, along with an RTC module that allows it to keep accurate time. When the alarm function goes off, you’re treated not to a normal buzzer, but the “soothing” tones of a dial-up modem via an MP3 module and speaker!

Binary clocks have always attracted my attention and here is my version. There are a number of design elements that I believe sets it apart from other variants described on Instructables and other internet sites:

• Addressable RGB LEDs have been mounted on a copper frame that is external to the body that houses the electronics.
• An IR remote is used to set the time / alarm, snooze the alarm, select a display colour.
• The alarm tone is able to be easily personalised.
• Its in a piece of driftwood!!

The use of the external frame to support the LEDs was due to how much I liked the completed look of the display. The original plan was to have it mounted inside a box, behind opaque perspex but this would have been a design crime!

If you want to work with round parts, a lathe is the tool to have, but takes some time to master. A full CNC version takes even more time and skill to understand, but mechanical engineer “Wade’o Design” has come up with something in between. Instead of running his machine with code directly, his device allows the operator to input numbers into an Arduino Uno-based controller pulled off of a mechanical drawing.

The machine then uses this information to automatically move the cutter with a pair of servos, turning out a perfect part. As an added feature, it maintains full manual control, but uses an encoder on each crank to read inputs and turn the servos in a kind of machine-by-wire setup. Cutter position is displayed on the interface screen in this mode, assisting the user even when making parts manually. 

You can see everything in action below, while more build details are available here.

Back in May, the Arduino team ran a physical computing workshop as part of the summer school program organized by the Copenhagen Institute of Interaction Design. Each workshop was taught in the context of the United Nations Sustainable Development Goals. The one-week long class focused on designing physical and interactive objects that can help kids understand the building blocks of the digital world and its foundation (e.g. the binary system, barcodes, RGB colors, digital images, digital sounds, programming, laser printing…) in an experiential and playful way.

Italian pedagogues have, at different stages, imagined innovative learning approaches where children are the center of their own learning process through a direct experience of phenomena and concepts applicable in the real world, which is a radical departure from the classic lecture-based system.

To implement this active and experiential learning approach they also designed tools that help children discover abstract concepts through play like, for example, the Montessori Pink Tower to introduce the concept of scale and the decimal system, or the tactile workshops by Bruno Munari to explore the sense of touch and textures.

In the XXI century, human experiences are increasingly mediated by digital tools, and the world we live in is going through a radical digital transformation which requires a deeper understanding of its complexity. To make this world more accessible, we need to encourage children to understand how these digital tools work and enable them to become active citizens of the future, rather than passive learners.

A handful of playful and engaging experiences have been designed by the students, which will allow children to understand a specific technology, such as how solar panel works, how to express colors in binary language, how RFID tags are able to activate objects, and even identify the principle behind accelerometers that we use everyday in video games controllers.

As if we didn’t have enough to worry about in regards to the coming robot uprising, [Ali Aslam] of Potent Printables has recently wrapped up work on a 3D printed robot that can flatten itself down to the point it can fit under doors and other tight spaces. Based on research done at UC Berkeley, this robot is built entirely from printed parts and off the shelf hardware, so anyone can have their own little slice of Skynet.

The key to the design are the folding “wings” which allow the robot to raise and lower itself on command. This not only helps it navigate tight spaces, but also gives it considerable all-terrain capability when it’s riding high. Rather than wheels or tracks, the design uses six rotors which look more like propellers than something you’d expect to find on a ground vehicle. These rotors work at the extreme angles necessary when the robot has lowered itself, and allow it to “step” over obstructions when they’re vertical.

For the electronics, things are about what you’d expect. An Arduino Pro Mini combined with tiny Pololu motor controllers is enough to get the bot rolling, and a Flysky FS-X6B receiver is onboard so the whole thing can be operated with a standard RC transmitter. The design could easily be adapted for WiFi or Bluetooth control if you’d rather not use RC gear for whatever reason.

Want to build your own? All of the STL files, as well as a complete Bill of Materials, are available on the Thingiverse page. [Ali] even has a series of videos on YouTube videos walking through the design and construction of the bot to help you along. Outside of the electronics, you’ll need a handful of screws and rods to complement the 50+ printed parts. Better start warming up the printer now.

As an interesting aside, we got a chance to see this little critter first hand at the recent East Coast RepRap Festival in Maryland, along with a number of other engineering marvels.

At this point you’ve almost certainly seen one of these low-cost portable soldering irons, perhaps best exemplified by the TS100, a pocket-sized temperature controlled iron that can be had for as little as $50 USD from the usual overseas suppliers. Whether or not you’re personally a fan of the portable irons compared to a soldering station, the fact remains that these small irons are becoming increasingly popular with hackers and makers that are operating on a budget or in a small workspace.

Believing that imitation is the most sincere form of flattery, [Electronoobs] has come up with a DIY portable soldering iron that the adventurous hacker can build themselves. Powered by an ATMega328p pulled out of an Arduino Nano, if offers the same software customization options of the TS100 but at a considerably lower price. Depending on where you source your components, you should be able to build one of these irons for as little as $15.

The iron features a custom PCB and MAX6675 thermocouple amplifier to measure tip temperature. A basic user interface is provided by two tactile buttons on the PCB as well as an 128×32 I2C OLED display. In a future version, [Electronoobs] says he will look into adding some kind of sensor to detect when the iron is actually being used and put it to sleep when inactive.

The tip is sourced from a cheap soldering station replacement iron, and according to [Electronoobs], is probably the weakest element of the entire build. He’s looking into using replacement TS100 tips, but says he’ll need to redesign his electronics to make it compatible. The case is a simple 3D printed affair, which looks solid enough, but seems likely to be streamlined in later versions.

We’ve seen a number of attempts at DIY soldering irons over the years, but we have to say, this one is probably the most professional we’ve ever seen. It will be interesting to see how future revisions improve on this already strong initial showing.

[XenonJohn] dabbles in cryptocurrency trading, and when he saw an opportunity to buy an RGB color sensor, his immediate thought — which he admitted to us would probably not be the immediate thought of most normal people — was that he could point it to his laptop screen and have it analyze the ratio of green (buy) orders to red (sell) orders being made for crypto trading. In theory, if at a given moment there are more people looking to buy than there are people looking to sell, the value of a commodity could be expected to go up slightly in the short-term. The reverse is true if a lot of sell orders coming in relative to buy orders. Having this information and possibly acting on it could be useful, but then again it might not. Either way, as far as out-of-left-field project ideas go, promoting an RGB color sensor to Cryptocurrency Trading Advisor is a pretty good one.

Since the RGB sensor only sees what is directly in front of it, [XenonJohn] assembled a sort of simple light guide. By enclosing the area of the screen that contains orders in foil-lined cardboard, the sensor can get a general approximation of the amount of red (sell orders) versus green (buy orders). The data gets read by an Arduino which does a simple analysis and sends alerts when a threshold is crossed. He dubbed it the Crypto-Eye, and a video demo is embedded below.

Could this have been done purely in software? Certainly, but there’s a certain charm to the Crypto-Eye being a standalone device that uses a simple visual input to make buy and sell predictions like a Speak & Spell.

Inventive crypto trading is just a side project for [XenonJohn], he’s better known around these parts for his outstanding contributions to one-wheeled electric vehicles, like this 3000W Electric Unicycle, which also happens to feature an Arduino with 80’s-style voice feedback, just like the Crypto-Eye.

We live in a world in which nearly any kind of gadget or tool you can imagine is just a few clicks away. In many respects, this has helped fuel the maker culture over the last decade or so; now that people aren’t limited to the hardware that’s available locally, they’re able to create bigger and better things than ever before. But it can also have a detrimental effect. One has to question, for instance, why they should go through the trouble of building something themselves when they could buy it, often for less than the cost of the individual components.

The critic could argue that many of the projects that grace the pages of Hackaday could be supplanted with commercially available counterparts. We don’t deny it. But the difference between buying a turn-key product and building an alternative yourself is that you can make it exactly how you want it. That is precisely why [Sam Izdat] created this truly one of a kind microphone preamplifier. Could he have bought one online for cheaper? Probably. Could he have saved himself an immense amount of time and effort? Undoubtedly. Do we care? Not in the slightest.

The amplifier is based on the Texas Instruments INA217 chip, with an Arduino Nano and 128×64 OLED display providing the visualization. [Sam] was able to find a bare PCB for a typical INA217 implementation on eBay for a few bucks (see what we mean?), which helped get him started and allowed him to spend more time on the software side of things. His visualization code offers a number of interesting display modes, uses Fast Hartley Transforms, and very nearly maxes out the Arduino.

But perhaps no element of this build is as unique as the case. The rationale behind the design is that [Sam] wanted to compartmentalize each section of the device (power supply, amplifier, visualization) to avoid any interference. The cylindrical shapes were an issue of practicality: the compartments were constructed by using a hole saw to make wooden discs, which were then glued together and hollowed out. The case was stained and coated with polyurethane, but due to some slightly overzealous use of glue and fillers, the coloring isn’t uniform. This gives the final piece a somewhat weathered look, in sharp contrast to the decidedly high-tech looking display.

Overall, this build reminds us of the modular 3D printed amplifier we saw earlier in the year combined with these speaker-integrated Arduino VU meters.