Three flowers in a corner of a darkened room, shining in different colors.

LED Flower Bouquet Is A Radiant Hacker Desk Decoration

March 15, 2022 by Arya Voronova 4 Comments

[Jeremy Cook] writes to us about a project of his – a bouquet of LED cube flowers. The flowers are PCB cubes made out of small castellated PCBs, each of those having an individually addressable LED in its center. Castellations hold the cubes together mechanically, and thanks to a cleverly chosen pinout, only two different kinds of PCB need to be ordered for building such a flower!

As a vase for these flowers, he decided to use a glass bottle – which would need a cutout to fit a ESP8266-powered NodeMCU board, a controller of choice for the project. After a few different approaches for cutting glass all resulted in the bottles cracking, he gave up on the “clean cut” idea and reused one of the broken bottles, gluing it back together well enough for the aesthetic to work.

[Jeremy] tells us that he’s had help from a hack we covered back in 2017 – using a diode for level shifting, as the ESP8266’s 3.3 V level signals aren’t a good match for WS2812 inputs. From there, the WLED firmware for the ESP8266 ties everything together beautifully. It’s clear that [Jeremy] had a field day designing this, toying with all the ideas and approaches!

Colorful LEDs are a must-have for decorating hacker homes. From a bouquet of flowers, you might find yourself sketching a castellated PCB tile design, and next thing you know, you’ve created a beautiful system of LED triangle tiles. Some PCB fabs scoff at castellations, and if that’s the case, you might as well finish the job yourself.

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Building A Pendulum Clock Out Of Lego

March 9, 2022 by Lewin Day 10 Comments

Pendulum clocks aren’t used quite as often these days as their cumbersome mechanics and timekeeping abilities have long been outshone by electronic alternatives. However, they’re still fun and they do work, so [PuzzLEGO] set about building a working example with Lego.

The rear view reveals the escapement built from Lego Technic parts.

The core of the clock is the escapement, a linkage which the pendulum can only turn in one direction. As the pendulum swings once per second, it lets the escapement gear turn one notch forward at a time, turning the gears of the clock which drive the hands. It’s powered with a falling weight in the form of a drink bottle full of water, which turns the gears of the clock via a chain.

The clock can only run for approximately an hour, so it’s set up with a second and minute hand instead of the more usual minute and hour hand. However, with the pendulum tuned to the appropriate length and the weight fitted, it pleasantly ticks and tocks the seconds away.

We’ve seen other great builds from [PuzzLEGO] before, too, like this inventive Rubik’s Cube build. Video after the break.

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USB Temperature Logger With Some Extra Tricks

March 7, 2022 by Dave Rowntree 5 Comments

Many of us electronics hacker types tend to have at least the same common equipment on our benches, namely a multimeter, an oscilloscope, some sort of adjustable power supply, and maybe a logic analyzer. These are great tools covering many bases, but dealing with temperature measurements is often neglected. A sudden need for such often results in just buying a either dedicated measurement unit, or some cheap eBay thermocouple board and just rolling with a few hacks. [Jana Marie Hemsing] had a need for measuring the thermal side of things, and got fed up with hacking with piles of boards, and designed herself a proper instrument for the task.

The result is a very tidy four-channel thermocouple frontend, feeding the data into the host computer via USB. Each of the four channels can either be a K-type input or a NTC thermistor input, decided at board assembly time, but you could just build two units with four channels of each and cover all bases. The K-type thermocouple input is based around the MAX31855 series device. While the ‘KASA’ suffixed device is probably most common, if you need to dedicate some channels to handling one of the other six or so other common thermocouple types, that just needs the appropriate MAX31855 variant dropping in, and you’re good to go.

For the controller, [Jana] has chosen the common STM32F0x microcontroller, which handles all the USB protocol side of things. The extra functionality added allows direct driving of a heater controller via the DRV8837 H-Bridge, with a extra few open collector outputs for other things you might want to drive. This allows the logger to function as a kind-of thermal IO device. Firmware is written in good old fashioned STM32 HAL, using the standard STM32CubeMX and the GCC toolchain. It looks like the Makefile came via the STM32 Project Generator route. The firmware has a neat trick up its sleeve too; with a flick of the switch on the back, the firmware can switch between outputting CSV data over a standard USB CDC link (a virtual serial port), or it can present a SCPI terminal interface, enabling integration into existing SCPI-based test flows. Nice work!

We’ve seen a few logging projects on these fair pages, like this battery powered ESP32 logger device. If IoT logging is more your thing, here you go.

Pop Goes The Mechanical Ping Pong Sculpture

March 7, 2022 by Matthew Carlson 12 Comments

In the waiting rooms of some dentists or doctors, you might have seen a giant metal ball rolling around in a large glass case. While it sure beats looking through those magazines, the sculpture can’t have come cheap. But not all of us want to pay high-end prices for fun toys. As a more cost-effective alternative, [JBV Creative] built an awesome 3D-printed ping pong sculpture.

The basic concept is the same as those fancy sculptures: a ball goes up, moves through some sort of impressive range of motion as it makes its way back down, and some sort of drive mechanism pushes it back to repeat the cycle anew. The design of this particular art piece is no different. A ping-pong ball falls down a funnel into a queue where balls are slowly loaded via a 12-way Geneva mechanism. An Archimedes spiral cam charges an elastic band that yeets the ball up and out of the track and sends it sailing through the air and down inside the funnel mentioned earlier. Everything on this sculpture is 3D-printed aside from the rubber bands and the ping pong balls.

What’s tricky about these sorts of things is the precision required both in printing and in design. It needs to run for hundreds if not thousands of hours and make no mistake. Making something work correctly 99% of the time is hard, but that last 1% can be almost as much work as that first 99%. [JBV Creative]’s first attempt had a catapult mechanism and he printed and tried out several scoops, but none gave the trajectory that he was looking for.

[JBV Creative] tried a plunger mechanism, but without a counterbalance weight providing the power, it just didn’t have enough oomph to launch the ball. Luckily, holes were included in the design, so it was relatively easy to adapt what had already been printed to use rubber bands instead. An additional goal was to have no visible fasteners, so everything needed to be mounted from the back. Check it out in action after the break.

It’s an incredible project that took serious thought, dedication, and in [JBV Creative]’s words, plenty of CAD twirling. It’s a great lesson in iterating and experimentation. If your talents are more soldering-based rather than CAD-based, perhaps a circuit sculpture is more up your alley?

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Astra’s Frugal Design Leads To Latest Unusual Failure

February 23, 2022 by Tom Nardi 36 Comments

We’ve all heard it said, and it bears repeating: getting to space is hard. But it actually gets even harder the smaller your booster is. That’s because the structure, engines, avionics, and useful payload of a rocket only make up a tiny portion of its liftoff mass, while the rest is dedicated to the propellant it must expend to reach orbital velocity. That’s why a Falcon 9 tipping the scales at 549,054 kilograms (1,207,920 pounds) can only loft a payload of 22,800 kg (50,265 lb) — roughly 4% of its takeoff weight.

As you might imagine, there’s a lower limit where there simply isn’t enough mass in the equation for the hardware necessary to build a fully functional rocket. But where is that limit? That’s precisely what aerospace newcomer Astra is trying to find out. Their Rocket 3 is among the smallest orbital boosters to ever fly, closer in size and mass to the German V2 of World War II than the towering vehicles being built by SpaceX or Blue Origin. Even the Rocket Lab Electron, itself an exceptionally svelte rocket, is considerably larger.

The reason they’re trying to build such a small rocket is of course very simple: smaller means cheaper. Assuming you’ve got a payload light and compact enough to fit on their launcher, Astra says they can put it into orbit for roughly $2.5 million USD; less than half the cost of a dedicated flight aboard Rocket Lab’s Electron, and competitive with SpaceX’s “rideshare” program. Such a low ticket price would have been unfathomable a decade ago, and promises to shake up an already highly competitive commercial launch market. But naturally, Astra has to get the thing flying reliably before we can celebrate this new spaceflight milestone.

Their latest mission ended in a total loss of the vehicle and payload when the upper stage tumbled out of control roughly three minutes after an otherwise perfect liftoff from Cape Canaveral Space Force Station in Florida. Such issues aren’t uncommon for a new orbital booster, and few rockets in history have entered regular service without a lost payload or two on the books. But this failure, broadcast live over the Internet, was something quite unusual: because of the unconventional design of Astra’s diminutive rocket, the upper stage appeared to get stuck inside the booster after the payload fairing failed to open fully.

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Color Dot Puzzle Will Wrinkle Your Brain

February 12, 2022 by Lewin Day 3 Comments

2022 is a good year for puzzles, and if you’re getting tired of Wordle, you might be after a new challenge. This color puzzle from [Sebastian Coddington] could be just what you’re looking for.

[Sebastian] describes the 4×4 Color Dot Puzzle as a sort of combination of the ideas behind the Rubik’s Cube and the 15 puzzle. The aim is to arrange the 16 colored tiles on the board to form four single-colored 2×2 squares in the overall 4×4 board. The puzzle is 3D printed, using 6 colors of filament – black for the body of the puzzle, white for the control sticks, and yellow, green, red, and blue for the individual tiles.

We haven’t seen any mathematical proofs of how to beat the game, but we’re sure [Sebastian] has gotten good at beating the puzzle having designed it himself. According to tipster [Michael Gardi], who knows a thing or two about 3D printing games himself, the puzzle makes for a fun little mind teaser.

If you’re more of a jigsaw person, consider this advanced illuminated build.

Hackaday Podcast 154: A Good Enough CNC, Stepper Motors Unrolled, Smart Two-Wire LEDs, A Volcano Heard Around The World

February 4, 2022 by Tom Nardi 1 Comment

Join Hackaday Editor-in-Chief Elliot Williams and Staff Writer Dan Maloney for this week’s podcast as we talk about Elliot’s “defection” to another podcast, the pros and cons of CNC builds, and making Nixie clocks better with more clicking. We’ll explore how citizen scientists are keeping a finger on the pulse of planet Earth, watch a 2D stepper go through its paces, and figure out how a minimalist addressable LED strip works. From solving a Rubik’s cube to answering the age-old question, “Does a watched pot boil?” — spoiler alert: if it’s well designed, yes — this episode has something for everyone.

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 (Less than 60 MB)