Palm-Sized Sixteen Segments Light The Way To Our Hearts

August 20, 2020 by Kerry Scharfglass 20 Comments

It’s no secret that we here at the Hackaday are suckers for cool display. LEDs, OLEDs, incandescent, nixie or neon, you name it and we want to see it flash. So it fills us with joy to discover a new way to build large, daisy-chainable 16-segment digits, and even more excited to learn how easy they are to fab and assemble.

A cousin of the familiar 7 segment display, the 16 segment gives so many more possibilities (128% more possibilities to be exact) for digit display. To be specific, those extra segments unlock the ability to display upper and lowercase latin characters as well as scads of punctuation.

But where the character set is complex, the assembly is anything but thanks to a great design from [Kolibri] called klais-16. They’re available fully assembled if you want to jump straight to code, but thanks to thorough documentation (seriously, check this out) assembly is a snap.

Each module is composed a very boring PCBA base layer which should be inexpensive from the usual sources, even when ordering one fully assembled. A stackup of three more PCBs are used for spacing and diffusion with plans for die-cut or injection mold layers if a larger production run ends up happening. Board dimensions for each character are 100 mm x 66.66 mm (about 4″ x 2.5″). Put together, each module can stand on its own or be easily daisy-chained together to make a longer single display.

Addressing all those bits with an elaborate, ugly control scheme would be a drag but fortunately the firmware for the onboard STM8 microcontroller exposes a nice boring serial interface which can be used without configuration to display strings. There’s even an example Windows Batch script!

Hackaday Podcast 078: Happy B-Day MP3, Eavesdropping On A Mars Probe, Shadowcasting 7-Segments, And A Spicy Commodore 64

July 31, 2020 by Mike Szczys No comments

Hackaday editors Elliot Williams and Mike Szczys go down the rabbit hole of hacky hacks. A talented group of radio amateurs have been recording and decoding the messages from Tianwen-1, the Mars probe launched by the Chinese National Space Administration on July 23rd. We don’t know exactly how magnets work, but know they do a great job of protecting your plasma cutter. You can’t beat the retro-chic look of a Commodore 64’s menu system, even if it’s tasked with something mundane like running a meat smoker. And take a walk with us down MP3’s memory lane.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 078: Happy B-Day MP3, Eavesdropping On A Mars Probe, Shadowcasting 7-Segments, And A Spicy Commodore 64” →

7-Segment Display Is No Small Feat

July 12, 2020 by Moritz v. Sivers 13 Comments

The 7-segment display certainly is a popular build, and surprisingly people still come up with new takes on this over a hundred-year-old way to represent numbers. This time [jegatheesan.soundarapandian] is making it big by building a giant 7 feet tall 7-segment display.

Apparently, the plan is to build a giant clock so he started off by making the first digit. To keep it cheap and simple the segments are made from corrugated cardboard which was carefully cut, folded, and then glued together. The light-diffusing lid is simply made from white paper. He used the ubiquitous WS2812B strips to light up the segments, but things turned out to be more complicated as he was not able to get enough strips to fill up all the segments. This forced him to cut up the strip into individual pieces and space them out by reconnecting the LEDs with wires. Cutting, stripping, and soldering 186 wires took him almost 10 hours. An Arduino Uno serves as the brains of the device and there is a nice Android app to control it via Bluetooth.

We are excited to see the complete clock once it is finished. In the meantime let us remember other epic displays like that made from 144 individual 7-segment displays or the giant LED video wall using 1200 ping pong balls.

Video after the break.

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This Freezer Failure Alarm Keeps Your Spoils Unspoiled

July 8, 2020 by Kristina Panos 25 Comments

Deep freezers are a great thing to have, especially when the world gets apocalyptic. Of course, freezers are only good when they’re operating properly. And since they’re usually chillin’ out of sight and full of precious goods, keeping an eye on them is important.

When [Adam] started looking at commercial freezer alarms, he found that most of them are a joke. A bunch are battery-powered, and many people complain that they’re too quiet to do any good. And you’d best hope that the freezer fails while you’re home and awake, because they just stop sounding the alarm after a certain amount of time, probably to save battery.

If you want something done right, you have to do it yourself. [Adam]’s homemade freezer failure alarm is a cheap and open solution that ticks all the boxen. It runs on mains power and uses a 100dB piezo buzzer for ear-splitting effectiveness to alert [Adam] whenever the freezer is at 32°F/0°C or above.

If the Arduino loses sight of the DHT22 temperature sensor inside the freezer, then the alarm sounds continuously. And if [Adam] is ever curious about the temperature in the freezer, it’s right there on the 7-segment. Pretty elegant if you ask us. We’ve got the demo video thawing after the break, but you might wanna turn your sound down a lot.

You could assume that the freezer is freezing as long as it has power. In that case, just use a 555.

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Servo-Powered 7-Segments Choreograph This Chronograph

April 22, 2020 by Kristina Panos 11 Comments

Good clocks are generally those that keep time well. But we think the mark of a great clock is one that can lure the observer into watching time pass. It doesn’t really matter how technical a timepiece is — watching sand shimmy through an hourglass has its merits, too. But just when we were sure that there was nothing new to be done in the realm of 7-segment clocks, [thediylife] said ‘hold my beer’ and produced this beauty.

A total of 28 servos are used to independently control four displays’ worth of 3D-printed segments. The servos pivot each segment back and forth 90° between two points: upward and flat-faced to display the time when called upon, and then down on its side to rest while its not needed.

Circuit-wise, the clock’s not all that complicated, though it certainly looks like a time-consuming build. The servos are controlled by an Arduino through a pair of 16-channel servo drivers, divided up by HH and MM segments. The Arduino fetches the time from a DS1302 RTC module and splits the result up into four-digit time. Code-wise, each digit gets its own array, which stores the active and inactive positions for each servo. Demo and full explanation of the build and code are waiting after the break.

When it comes to 7-segment displays, we say the more the merrier. Here’s a clock that uses pretty much all of them.

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144 7-Segment Displays Combine To Form A Mighty Clock

March 5, 2020 by Adam Fabio 25 Comments

What do you do with 144 7-segment displays? If you’re [Frugha] you put them all together to create an epic clock. Each display has 8 individual LEDs — 7 segments, and a decimal point. Put that all together, and you’ve got 1152 individual LEDs to control. This presented a problem, as [Frugha] wanted to control the clock with a single Arduino Nano. Even charlieplexing won’t get you that many I/O lines.

The solution was a nifty little chip called the MAX7219. The ‘7219 speaks SPI and can control 64 individual LEDs. [Frugha] used 18 of them in the clock, giving him full control over all his LEDs. That’s pretty impressive, considering the last matrix 7-segment display we saw required 48 Arduinos!

Another problem is memory – 1152 “pixels” would quickly overrun the 2KB RAM in the ATmega328. This is a clock though — which means only digits 0-9 and a colon. [Frugha] picked a nice font and hand-coded lookup tables for each digit. The lookup tables are stored in ROM, saving precious RAM on the Arduino.

A clock wouldn’t be any good if it wasn’t accurate. A Tiny RTC supplies battery-backed time data. [Frugha] wrapped everything up with a neat layout on a custom PCB. Sure, you could put it in a case, but we think a clock this crazy deserves to be left open – so you can see it in all its glory.

Hackaday Podcast 040: 3D Printed Everything, Strength V Toughness, Blades Of Fiber, And What Can’t Coffee Do?

October 18, 2019 by Mike Szczys No comments

Hackaday Editors Mike Szczys and Elliot Williams opine on the coolest hacks we saw this week. This episode is heavy with 3D printing as Prusa released a new, smaller printer, printed gearboxes continue to impress us with their power and design, hoverboards are turned into tanks, and researchers suggest you pour used coffee grounds into your prints. Don’t throw out those “toy” computers, they may be hiding vintage processors. And we have a pair of fantastic articles that cover the rise and fall of forest fire watchtowers, and raise the question of where all those wind turbine blades will go when we’re done with them.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)