A set of brass safety glasses sit on a marred black workbench. The top and earpiece sections of the frames are in squarish brass plate and have ruler marks on them.

Combination Safety Glasses And Measurement Tool

November 8, 2024 by Navarre Bartz 19 Comments

While rulers and tape measures are ubiquitous, they always seem to disappear when you need them. We know you’d never forget your safety glasses (safety first!), so what if they were also a measuring tool?

Starting by snapping pieces from a folding yardstick, [Simone Giertz] and [Laura Kampf] worked out a rough prototype before letting [Giertz] complete the project in brass. Some initial issues with the weight of the frames were alleviated by switching to a lighter weight plate material and using thinner frames and weight-saving holes near the ear pieces.

Beauty is in the eye of the beholder, so we’ll let somebody else decide whether or not these will be the newest fashion craze. But it’s hard to argue with the timelessness of brass unless you have a copper allergy. We could definitely see a less expensive plastic version catching on in makerspaces for the PPE bin.

Want some other cool wearable gear? How about [Giertz]’s grocery bag hat, an evening gown with servo-driven flowers, or a shirt that reflects heat out the atmospheric window?

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Rulers Of The Ancient World — Literally!

July 13, 2024 by Al Williams 29 Comments

If you were expecting a post about ancient kings and queens, you are probably at the wrong website. [Burn Heart] has a fascination with ancient measuring devices and set out to recreate period-correct rules, although using decidedly modern techniques.

The first example is a French rule for measuring the “pied du Roi” or king’s foot. Apparently, his royal highness had large feet as a the French variant is nearly 13 inches long. The next rulers hail from Egypt and measure cubits and spans. Turns out the pyramid builders left a lot of information about measurements and their understanding of math and tools like dividers.

Other rules from Rome, Japan, and the Indus Valley are also included. According to the post, one set of these rulers used locally sourced wood, but a second “limited” edition used wood that the originals might have. Most of the rulers were etched via CNC, although the French ruler was hand-etched.

The Romans, apparently, had smaller feet than French royalty, as their Pes or foot was about 11.65 inches. There are plenty of little tidbits in the post ranging from the origin of the word inch to why the black wood used for piano keys is called ebony.

We’ll stipulate this isn’t exactly a hack, although it is fine workmanship and part of hacker culture is obsessing over measuring things, so we thought it was fair game. These days, rulers are often electronic. Which makes it natural to put them on a PC board.

Smart Ruler Has Many Features

December 2, 2021 by Bryan Cockfield 12 Comments

For those of us who remember old ball mice, they were a lot like modern optical mice except that they needed to be cleaned constantly. Having optical mice as a standard way of interacting with a computer is a major improvement over previous eras in computing. With extinction of the ball mouse, there are an uncountable number of cheap optical mice around now which are easy pickings for modern hacking, and this latest project from [Vipul] shows off some of the ways that optical mice can be repurposed by building a digital ruler.

The build seems straightforward on the surface. As the ruler is passed over a surface the device keeps track of exactly how far it has moved, making it an effective and very accurate ruler. To built it, the optical component of a mouse was scavenged and mated directly to a Raspberry Pi Zero W over USB. Originally he intended to use an ESP32 but could not get the USB interface to work. [Vipul] was then able to write some software which can read the information from the mouse’s PCB directly and translate it into human-readable form where it is displayed on a small screen. The entire device is housed in a custom 3D-printed enclosure to wrap everything up, but the build doesn’t stop there though. [Vipul] also leveraged the Bluetooth functionality of the Pi and wrote a smartphone app which can be used to control the ruler as well.

While the device does have some limitations in that it has to make contact with the object being measured across its entire length, there are some situations where we can imagine something like this being extremely useful especially when measuring things that aren’t a straight line. [Vipul] has also made all of the code for this project publicly available for those of us who might have other uses in mind for something like this. We’ve seen optical mice repurposed for all kinds of things in the past, too, including measuring travel distances in autonomous vehicles.

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Unique Instrument Plucks Out Notes On A Ruler

August 10, 2020 by Dan Maloney 18 Comments

How does one describe the notes that come from a ruler that is anchored on one end and then plucked? The best word we can come up with is “wubulation”. So would that make this ruler-plucking synthesizer a “wubulator”? Or perhaps a “wubatron”?

Whatever we decide to call it, [Dmitry Morozov] dubbed it the RBS-20, or “ruler bass synth, 20-cm”, for the 20-cm stainless steel ruler that forms the heart of the instrument. The ruler is attached to a linear slide which varies the length of the sprung section. A pair of servos can pluck the free section of the ruler in two different places, providing notes in different registers, while another pair of servos control metal fingers that can damp the vibration, change the sustain, and alter the notes. There’s no resonator; the sounds are instead picked up by a piezo mic. Twelve keys on the base of the instrument can be programmed for various lengths, and an OLED display gives the musician feedback. The video below shows the instrument wubulating, and brings us back to those desktop jam sessions in our grade school days — at least until the rulers were confiscated.

We’ve covered a ton of similarly unique musical instruments before, like this hybrid synthesizer-violin, a symphony of soda bottles, and inexplicably, a leg guitar.

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Programmable Ruler Keeps 1970’s Computing Alive

March 2, 2019 by Tom Nardi 23 Comments

A ruler seems like a pretty simple device; just a nice straight piece of material with some marks on it. There are some improvements out there to the basic design, like making it out of something flexible or printing a few useful crib notes and formulas on it so you have a handy reference. But for the most part, we can all agree that ruler technology has pretty much plateaued.

Well, not if [Brad] has anything to say about it. His latest creation, the Digirule2, is essentially an 8-bit computer like those of the 1970’s that just so happens to be a functional ruler as well. Forget lugging out the Altair 8800 next time you’re in the mood for some old school software development, now you can get the same experience with a piece of hardware that lives in your pencil cup.

Even if you’ve never commanded one of the blinkenlight behemoths that inspired the Digirule2, this is an excellent way to get some hands-on experience with early computer technology. Available for about the cost of a large pizza on Tindie, it represents one of the easiest and most cost-effective ways to tell your friends that as a matter of fact you have programmed a computer in binary.

The Digirule2 is powered by a Microchip PIC18F43K20, and is programmed by punching binary in one byte at a time with a bank of eight tactile switches. To make things a little easier, programs can be saved to the internal EEPROM and loaded back up just as easily thanks to the handy buttons next to the power switch. Now all you’ve got to do is figure out what all those blinking LEDs mean, and you’ll be in business.

The original Digirule was a logic gate simulator that we first covered back in 2015. We’re always happy to see projects grow and evolve over time, and think this new retro-computer themed variant is going to be quite popular with those who still love toggle switches and blinking lights.

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The People, Talks, And Swag Of Open Hardware Summit

October 10, 2016 by Mike Szczys 6 Comments

Friday was the 2016 Open Hardware Summit, a yearly gathering of people who believe in the power of open design. The use of the term “summit” rather than “conference” is telling. This gathering brings together a critical mass of people running hardware companies that adhere to the ideal of “open”, but this isn’t at the exclusion of anyone — all are welcome to attend. Hackaday has built the world’s largest repository of Open Hardware projects. We didn’t just want to be there — We sponsored, sent a team of people, and thoroughly enjoyed ourselves in the process.

Join me after the break for a look at the talks, a walk through the swag bags, and a feel for what this wonderful day held.

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Electronic Ruler Works Out Logic Truth Tables

October 13, 2015 by Mike Szczys 23 Comments

Like [Brad], we’ve seen a number of PCB rulers out there. [Brad] was looking to take the idea and run with it. His DigiRule is a ruler with a logic gate simulator. What he built is a mash-up between PCB rulers, and the concept of electronic business cards.

All told it simulates seven logic gates, four flip-flops, and includes a four-bit counter. On one end of the ruler a CR1220 battery feeds the 18F43K20 which is performing the logic operations using buttons and LEDs. Of course the truth tables are printed on the back silk-screen, but playing with the lights is a lot more fun. We do find it fairly amusing that the centimeters on the bottom of the ruler are notated in binary.

It makes a lot more sense to hand out rulers than business cards; people might actually use them after you leave and you can still include contact info. This form-factor also breaks the mold. You can have a lot more space on a ruler and you’re not constrained by thickness (although [Limpkin] solved that problem). While we’re on the topic of business cards [ch00f’s] USB etch-a-sketch style card and this logic-based information delivery device top our favorites list.

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