The BLE Datalogging Scale Of A Thousand Uses

Whether you’re making coffee or beer or complex chemicals, weighing your ingredients carefully and tracking them is key to getting good results. [Tech Dregs] decided to build a logging scale that would work seamlessly with his smartphone, and shared the design on YouTube.

The design begins with a Greater Goods manual electronic scale, which was chosen for its convenient design and 750 gram load cell. Once cracked open, [Tech Dregs] pulled out the original PCB to replace it with his own. Only the original buttons are used, with an Seed Xiao ESP32-C3 replacing the scale’s original brains. The original LCD screen was swapped out for an OLED display, and it also got a rechargeable lithium battery for better usability.

The real value of the project, though, is its communication capability. It’s able to talk to an Android smartphone over Bluetooth Low Energy. Thanks to a custom app, [Tech Dregs] is able to log weight readings from the scale over time and even graph them live on the smartphone. As a demonstration, the scale is used to log the weight of a cup as it fills with a shot of coffee, which should serve [Tech Dregs] well in his coffee automation projects.

We’ve seen bathroom scales hacked before, too, with similar connectivity upgrades.

Continue reading “The BLE Datalogging Scale Of A Thousand Uses”

PCB Gets Weighty Assignment

[Curious Scientist] tried building an integrated strain gauge on a PCB, but ran into problems. Mainly, the low resistance of the traces didn’t show enough change under strain to measure easily. Even placing a proper strain gauge on the PCB had limitations. His new design uses a bridge design to make the change in the gauges usefully large. You can see a video of the project below.

Bridging strain gauges isn’t a new idea. However, the novelty of this design is that the PCB has cantilever beams that facilitate the weighing. Standoffs mount a plate to the beams so that weight on the plate cause deformation on the beam that the strain gauges can measure.

Continue reading “PCB Gets Weighty Assignment”

Digital Kitchen Spoon Makes Weighing Your Ingredients A Snap

There seem to be two camps when it comes to recipes: those based on volume-based measurements, and those based on the weight of ingredients. Gravimetric measurements have the advantage of better accuracy, but at the price of not being able to quickly scoop out a bit of this and a dash of that. It would be nice to get the convenience of volumetric measurements with the accuracy of weighing your ingredients, wouldn’t it?

It would, and that’s just what [Penguin DIY] did with this digital kitchen spoon scale. The build started with, perhaps not surprisingly, a large mixing spoon and a very small kitchen scale. The bowl of the spoon got lopped off the handle and attached to the strain gauge, which was removed from the scale along with its LCD display and circuit board. To hold everything, a somewhat stocky handle was fabricated from epoxy resin sandwiched between aluminum bolsters. Compartments for the original electronics parts, as well as a LiPo battery and USB charger module, were carved out of the resin block, and the electronics were mounted so that the display and controls are easily accessible. The video below shows the build as well as the spoon-scale in action in the kitchen.

We think this is not only a great idea but a fantastic execution. The black epoxy and aluminum look amazing together on the handle, almost like a commercial product. And sure, it would have been easy enough to build a scale from scratch — heck, you might even be able to do away with the strain gauge — but tearing apart an existing scale seems like the right move here.

Continue reading “Digital Kitchen Spoon Makes Weighing Your Ingredients A Snap”

Hackaday Links Column Banner

Hackaday Links: July 24, 2022

OK, maybe that won’t buff right out. NASA has released a more detailed analysis of the damage suffered by the James Webb Space Telescope in a run-in with a micrometeoroid, and has deemed the damage “uncorrectable”. Not that any damage to JWST is correctable, at least in the sense that the Hubble Space Telescope was able to be fitted with optics to fix its precisely-yet-inaccurately-ground main mirror. JWST is far too remote for a service call, so correctability in this case refers to a combination of what can be accomplished by tweaking the shape and position of the affected mirror segment, and what can be taken care of with image processing. The damage to segment C3, as well as damage to the other segments in a total of six collisions in the half year Webb has been on station, are assessed via “wavefront sensing”, which looks at how out of phase the light coming from each mirror segment is. The damage sounds bad, and it certainly must hurt for the techs and engineers who so lovingly and painstakingly built the thing to see it dinged up already, but in the long run, this damage shouldn’t hamper Webb’s long-term science goals.

In other space news, we hear that the Perseverance rover has taken its first chunk out of the ancient river delta in Jezero Crater. The rover has been poking around looking for something interesting to sample, but everything it tried out with its abrading tool was either too brittle, too hard to get at, or scientifically dull. Eventually the rover found a good spot to drill, and managed to bring up a 6.7-cm core sample. This makes the tenth core sample collected overall, and the first from the delta area, which is thought to have the best chance to contain evidence of ancient Martian life.

Closer to home, we’ve all likely heard of robotic surgery, but the image that conjures up doesn’t really comport with reality. Robot-assisted surgery is probably a better term, since surgical robots are generally just ultra-precise remote manipulators that are guided by a skilled surgeon. But if a study on surgery robot performance is any indication, the days of human surgeons might be numbered. The study compared accuracy and speed of both a human surgeon controlling a standard Da Vinci surgical robot and an autonomous version of the robot alone, using a depth camera for sensing. Using a standard surgical skills test, the autonomous system matched the human surgeons in terms of failures — thankfully, no “oopsies” for either — but bested the humans in speed and positional accuracy. It’ll probably be a while before fully autonomous surgeons are a thing, but we wouldn’t be betting against it in the long run.

Most readers will no doubt have heard the exciting news that Supercon will be back this year as an in-person event! Make sure you set aside the first weekend in November to make the pilgrimage to Pasadena — it’ll be great seeing everyone again after the long absence. But if you just can’t wait till November for an IRL con, consider dropping by SCALE 19X, coming up this week in Los Angeles. The Southern California Linux Expo is being held July 28 through 31, and features a ton of speakers, including a keynote by Vint Cerf. Hackaday readers can save 50% on tickets with promo code HACK.

And finally, as a lover of Easter eggs of all kinds, but specifically of the hidden message in software variety, we appreciated this ode to the Easter egg, the embedded artistry that has served as a creative outlet for programmers over the years. The article lists a few great examples of the art form, along with explaining why they’re actually important artifacts of the tech world and what they’re good for. We tried out a few of the ones listed in the article that we hadn’t heard of before; some hits, some misses, but they’re all appreciated. Well, most of them — the corporate rah-rah kind can bugger straight off as far as we’re concerned.

Automated musical instrument with LED array

ESP32 Is The Brains Behind This Art Installation

The ESP32 has enabled an uncountable number of small electronics projects and even some commercial products, thanks to its small size, low price point, and wireless capabilities. Plenty of remote sensors, lighting setups, and even home automation projects now run on this small faithful chip. But being relegated to an electronics enclosure controlling a small electrical setup isn’t all that these tiny chips can do as [Eirik Brandal] shows us with this unique piece of audio and visual art.

The project is essentially a small, automated synthesizer that has a series of arrays programmed into it that correspond to various musical scales. Any of these can be selected for the instrument to play through. The notes of the scale are shuffled through with some random variations, allowing for a completely automated musical instrument. The musical generation is entirely analog as well, created by some oscillators, amplifiers, and other filtering and effects. The ESP32 also controls a lighting sculpture that illuminates a series of LEDs as the music plays.

The art installation itself creates quite haunting, mesmerizing tunes that are illustrated in the video linked after the break. While it’s not quite to the realm of artificial intelligence since it uses pre-programmed patterns with some randomness mixed in, it does give us hints of some other projects that have used AI in order to compose new music.

Continue reading “ESP32 Is The Brains Behind This Art Installation”

Pinewood Derby Scale Measures CG

If you suffer from nostalgia, you might remember carving a block of wood into a car, adding some wheels, and racing it against other contestants in a pinewood derby. Today’s derby is decidedly high tech though, and we were impressed with this car scale that also figures out the car’s center of gravity.

Based on an Arduino, of course, along with a pair of HX711 load cells. Why a pair? That’s how the device measures the center of gravity is by weighing the front and rear of the car separately.

Continue reading “Pinewood Derby Scale Measures CG”

A Model Of Dry Humor

If you want to see a glorious combination of model bananas in a treehouse mixed with a lot of tongue-in-cheek humor, you will appreciate [Studson]’s build video. Video also after the break. He is making an homage to Donkey Kong 64 from 1999, which may be a long time ago for some folks’ memory (Expansion Pak). Grab a piece of your favorite banana-flavored fruit and sit tight for joke delivery as dry as his batch of baked bark.

The treehouse uses a mixture of found material and crafting supplies. In a colorful twist, all the brown bark-wielding sticks are green, while the decorative greenery came from a modeling store shelf. It all starts with a forked branch pruned from the backyard and a smooth-sided container lid that might make you look twice the next time you nuts are buying a bin of assorted kernels. If you thought coffee stirrers couldn’t be used outside their intended purpose, prepare to have your eyes opened, but remember to wear eye protection as some of the wood clippings look like they could achieve escape velocity. The key to making this look like an ape abode, and not a birdhouse, is the color choices and finishing techniques. Judging by the outcome and compared to the steps, making a model of this caliber is the sign of an expert.

If you wish to binge on wooden Donkey Kong, we can grant your desire, but if you prefer your treehouses life-sized, this may launch your imagination.

Continue reading “A Model Of Dry Humor”