Sun-Seeking Sundial Self-Calibrates In No Time

May 6, 2020 by Kristina Panos 26 Comments

Sundials, one of humanity’s oldest ways of telling time, are typically permanent installations. The very good reason for this is that telling time by the sun with any degree of accuracy requires two-dimensional calibration — once for cardinal direction, and the other for local latitude.

[poblocki1982] is an amateur astronomer and semi-professional sundial enthusiast who took the time to make a self-calibrating equatorial ‘dial that can be used anywhere the sun shines. All this solar beauty needs is a level surface and a few seconds to find its bearings.

Switch it on, set it down, and the sundial spins around on a continuous-rotation servo until the HMC5883L compass module finds the north-south orientation. Then the GPS module determines the latitude, and a 180° servo pans the plate until it finds the ideal position. Everything is controlled with an Arduino Nano and runs on a 9V battery, although we’d love to see it run on solar power someday. Or would that be flying too close to the sun? Check out how fast this thing calibrates itself in the short demo after the break.

Not quite portable enough for you? Here’s a reverse sundial you wear on your wrist.

Celebrate Spring With A DIY Vibration Sensor

May 6, 2020 by Kristina Panos 10 Comments

Is your heaving pile of electronic parts shrinking by the day as you finish old back-burnered projects and come up with new ones? Try an old pastime that never gets old: rolling your own sensors using household objects. [Nematic!] needs a way to sense vibration for an upcoming project. Instead of spending $1 plus shipping and waiting who knows how long for a spring vibration sensor to come in the mail, they made one in a matter of minutes.

A spring vibration sensor is a simple device that can be used as a poor man’s accelerometer, or simply to detect vibration. All you need is a length of conductive wire, a 10 kΩ resistor, and a way to pick up those good vibrations. For the purposes of demonstration, [Nematic!] is using an Arduino Nano in the short build video after the break.

The wire is wound around the threads of a bolt to form a coil that’s just large enough for a resistor to fit inside. One end of the coil is connected to 5 V, and one leg of the resistor connects to an input pin. Together, they form a normally-open switch. When vibrations force the free ends of both to touch, the circuit is complete and the pin is pulled high.

If you make one of these and find the sensitivity is off, just twist up a new coil with stiffer or softer wire depending on the problem. Iterating doesn’t get much cheaper than wrapping wire around a bolt. We can’t wait to see how [Nematic!] will use this sensor. In the meantime, we’re planning to use one to detect when the dryer stops running and send a text.

Speaking of bargain basement sensors, did you know you can detect water leaks with two pennies, an aspirin, and a clothespin? These projects demonstrate the kind of ingenuity that can win you a pile of toys in our new Making Tech At Home contest, running now through July 28th, 2020.

Continue reading “Celebrate Spring With A DIY Vibration Sensor” →

Watch The Day Inch Along With A Tape Measure Clock

April 27, 2020 by Kristina Panos 24 Comments

If we asked you to rattle off all the tools at your own personal disposal, you’d probably leave your timepieces off the list. But we say clocks are definitely tools — cool tools that come in countless forms and give meaning to endless days.

A clock form we hadn’t considered was that of an actual tool. So we were immeasurably delighted to see [scealux]’s clock made from a measuring tape. At least, the time-telling part of the clock is made from a measuring tape. The case isn’t really from a tape measure — it’s entirely printed, Bondo’d, sanded, and painted so well that it’s quite easy to mistake it for the real thing.

Tightly packed inside this piece of functional art is an Arduino Nano and a DS3231 precision RTC module, which we think is fitting for a tool-based clock. The Nano fetches the time and drives a stepper motor that just barely fits inside. There’s just enough tape wound around the printed hub to measure out the time in increments of one hour per inch. Take 1/16″ or so and watch the demo and brief walk-through video after the break.

Not all tools are sharp, and not all clocks are meant to be precise. Here’s a clock for the times that gives you the gist.

Continue reading “Watch The Day Inch Along With A Tape Measure Clock” →

The Three Shell Mystery Finally Solved!

April 16, 2020 by Moritz v. Sivers 9 Comments

While we certainly acknowledge the valuable contributions of the open hardware community that help to mitigate the coronavirus crisis, we are also looking forward to the days when people start going back to building other things than 3D-printed face shields, pandemic trackers, and automatic soap dispensers. However, this handwash timer by [Agis Wichert] is a very creative version that also tries to solve the long outstanding mystery of how to use the three seashells. Unfortunately, in contrast to those in the original movie, these three seashells do not replace toilet paper which many people are seemingly so desperate in need of at the moment.

The build is quite simple and requires only a few off-the-shelf components including a Neopixel strip, IR proximity sensor, and an Arduino Nano. The plastic seashells were taken from the classic German “Schleckmuschel” candy, thereby giving the project an extra retro twist. As shown in the video embedded below, the timer works by consecutively dimming the LEDs located under each seashell until the recommended duration of 20 seconds has elapsed which is indicated by shortly flashing all LEDs.

Handwash timer projects do not always have to be visual as this one playing your favorite Spotify tunes proves. What we really would like to see though is someone building a toilet paper dispenser that is triggered by swearwords.

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Pulse Visualizer Is A Real Work Of Heart

April 15, 2020 by Kristina Panos 4 Comments

Some projects are all-around simple, such as the lemon battery or the potato clock. Other projects are rooted in simple ideas, but their design and execution elevates them to another level. [Sharathnaik]’s heart visualizer may not be all that electronically complex, but the execution is pulse-pounding.

The closest that most of us will get to seeing our own heartbeat is watching the skin twitch in our neck or wrist. You know that your heart doing the work of keeping you alive, but it’s hard to appreciate how it exerts itself. With just a few components and printed parts, the heart’s pumping action comes to life as your pulse drives single-x scissor mechanisms to push and pull the plastic plates.

This heart visualizer isn’t nearly as complex as the organ it models, and it’s an easy build for anyone just starting out in electronics. Put your finger on the heart rate sensor in the base, and an Arduino Nano actuates a single servo to your own personal beat. We’d love to see it work overtime while someone gets worked up. For now, there’s an even-tempered demo after the break, followed by an assembly video.

Heartbeat sensing can be romantic, too. Here’s a lovely circuit sculpture that runs at the rate of the receiver.

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LED Heart Beats With The Beholder

April 3, 2020 by Lewin Day 9 Comments

Many a maker likes to use their craft to create gifts for loved ones. [Jiří Praus] was celebrating having been married for 5 years, and crafted this beautiful LED heart sculpture to commemorate the occasion.

The outer shell was created by first starting with a 3D printed heart shape. This was used as a form upon which the brass wire could be soldered together to form an attractive heart-shaped cage. Inside, an Arduino Nano is hooked up to a series of WS2812b LEDs. The LEDs are flashed in time with the heartbeat of the person holding the heart, thanks to a MAX30102 heartbeat sensor. There’s also a TP4056 charge module and a small lithium battery to provide power for the device.

Adding the heartbeat sensor really makes this project shine, forming a connection between the holder and the device itself. The tasteful craftsmanship of the brass design makes this an excellent gift, one we’re sure anyone would like to receive. We’ve seen [Jiří Praus] make the most of this artform before too, with projects like this stunning tulip or dead-bug Arduino. Video after the break. Continue reading “LED Heart Beats With The Beholder” →

Minimalist Magnetic Minute Minder Mesmerizes

April 3, 2020 by Kristina Panos 26 Comments

Timepieces are cool no matter how simplistic or granular they are. Sometimes its nice not to know exactly what time it is down to the second, and most of the really beautiful clocks are simple as can be. If you didn’t know this was a clock, it would still be fascinating to watch the bearings race around the face.

This clock takes design cues from the Story clock, a visual revolution in counting down time which uses magnetic levitation to move a single bearing around the face exactly once over a duration of any length as set by the user. As a clock, it’s not very useful, so there’s a digital readout that still doesn’t justify the $800 price tag.

[tomatoskins] designed a DIY version that’s far more elegant. It has two ball bearings that move around the surface against hidden magnets — an hour ball and a minute ball. Inside there’s a pair of 3D-printed ring gears that are each driven by a stepper motor and controlled with an Arduino Nano and a real-time clock module. The body is made of plywood reclaimed from a bed frame, and [tomatoskins] added a walnut veneer for timeless class.

In addition to the code, STLs, and CAD files that birthed the STLs, [tomatoskins] has a juicy 3D-printing tip to offer. The gears had to be printed in interlocked pieces, but these seams can be sealed with a solution of acetone and plastic from supports and failed prints.

If you dig minimalism but think this clock is a bit too vague to read, here’s a huge digital clock made from small analog clocks.