Low cost 3D printers have come a long way in the last few years, but have entry-level CNC machines improved by the same leaps and bounds? That’s what [ModBot] recently set out to find. Despite getting burned pretty badly on a cheap CNC a few years back, he decided to try again with a sub $400 machine from FoxAlien. You can see his full review after the break.

The machine looks very similar to other generic CNC machines you see under many brand names, sometimes for a good bit less. The 3018 number is a giveaway that the work area is 30×18 cm and a quick search pulled up several similar machines for just a bit more than $200. The FoxAlien did have a few nice features, though. It has a good-looking build guide and an acrylic box to keep down the shaving debris in your shop. There are also some other nice touches like a Z-axis probe and end stops. If you add those items to the cut-rate 3018 machines, the FoxAlien machine is pretty price competitive when you buy it from the vendor’s website. The Amazon page in the video shows $350 which is a bit more expensive but does include shipping.

As with most of these cheap CNC machines, one could argue that it’s more of an engraver than a full mill. But on the plug side, you can mount other tools and spindles to get different results. You can even turn one of these into a diode laser cutter, but you might be better off with something purpose-built unless you think you’ll want to switch back and forth often.

This reminded us of a CNC we’ve used a lot, the LinkSprite. It does fine for about the same price but we are jealous of the enclosure. Of course, half the fun of owning something like this is hacking it and there are plenty of upgrades for these cheap machines.

source https://hackaday.com/2021/01/02/checking-in-on-low-cost-cnc-machines/

Ever heard of a handpan? If not, imagine a steel drum turned inside out, and in case that doesn’t help either, just think of a big metal pan you play music with by tapping your hands on its differently pitched tone fields. But as with pretty much any musical instrument, the people around you may not appreciate your enthusiasm to practice playing it at any time of the day, and being an acoustic instrument, it gets difficult to just plug in your headphones. Good news for the aspiring practitioners of Caribbean music though, as [Deepsoul77] created a MIDI version of this rather young and exotic instrument.

Using the foam salvaged from an old mattress as the core of the handpan, [Deepsoul77] cut a couple of plywood pads as tone fields that will be attached to the foam. Each plywood tone field will then have a piezo element mounted in between to pick up the hand tapping. Picking up the tapping itself and turning it into MIDI signals is then handled by an Alesis trigger interface, which is something you would usually find in electronic drums. From here on forward, it all becomes just a simple USB MIDI device, with all the perks that brings along — like headphone usage or changing MIDI instruments to make anything sound like a trumpet.

Turning what’s essentially a drum kit into a melodic instrument is definitely neat, and to no surprise, we’ve also seen the actual home made drum kit with piezo elements. Of course, using MIDI to quiet down an acoustic instrument isn’t new either, though it also works somewhat the other way around. But then again, it doesn’t always have to be MIDI either.

source https://hackaday.com/2021/01/02/mattress-made-midi-device-plays-exotic-tunes/

There are multiple reasons why we like [iSax]’s rebuild of a Bodet flip clock from the early 1980s. First there’s the retro charm of the timepiece itself, then the electronics used to drive it, its electromechanical month length and leap year system, and finally because here is a maker lucky enough to have a beautiful tabby cat to share the workbench with.

For those of you unfamiliar with a flip clock, these devices have their digits as a series of hinged cards on a central rotor, with each one being exposed in turn as the rotor turns. This one is part of a distributed clock system in which the clients receive a 1 Hz pulse from a central time server to drive their motors, something easily replicated with an Arduino and an H-bridge. Particularly fascinating though is the month length mechanism, part of the calendar rotor system, it has a small DC motor that is engaged to advance the days automatically by whichever number as part of the month transition. Originally this was powered by a couple of AA batteries, which have now been replaced with a small DC to DC converter. You can see it in action in the video below the break.

With or without tabby cats, we see quite a few projects featuring them. If you can’t find one, you can always make your own.

source https://hackaday.com/2021/01/02/a-vintage-flip-clock-gets-some-modern-love/

Sometime around 2009, [J. Clark Scott] published a book aimed to demystify computers for everyone by walking through construction of an 8-bit CPU from scratch. The book had a catchy, but somewhat confusing title But How Do It Know?. The back story on the title goes something like this: Joe is a very nice fellow, but has always been a little slow. He goes into a store where a salesman is standing on a soapbox in front of a group of people. The salesman is pitching the miracle new invention, the Thermos bottle. He is saying, “It keeps hot food hot, and cold food cold….” Joe thinks about this a minute, amazed by this new invention that is able to make a decision about which of two different things it is supposed to do depending on what kind of food you put in it. He can’t contain his curiosity, he is jumping up and down, waving his arm in the air, saying “but, but, but, but…” Finally he blurts out his burning question “But how do it know?” Joe looked at what this Thermos bottle could do, and decided that it must be capable of sensing something about its contents, and then performing a heating or cooling operation accordingly. Joe’s concept of how the bottle worked was far more complicated than the truth. With that introductory opening, [J. Clark Scott] goes on to cover basic number theory, leading on to logic gates, and finally the 8-bit CPU.

[Patrick LeBoutillier] decided to build a hardware version of the CPU/computer as described in [John Clark Scott]’s book. In order to keep size and cost within reasonable bounds, he choose a hybrid construction using a combination of micro-controllers and SN74HC logic IC’s. When used as a companion project alongside reading the book, he hopes people can get their hands dirty and try it out for themselves. He has published a series of 14 videos covering construction of the CPU and the first Introductory video is embedded after the break below. For the micro-controller part of the project, he is using four Arduino Nanos, the code and install instructions for which are available at his Git repo. The Fritzing schematic, also available at the repo, might look a bit daunting at first look, but when you follow along his video series, it becomes easier. You can preview the first three chapters of the book at the “But How Do It Know?” website.

If FPGA’s are more of a thing for you, or you’d like to dip your feet learning FPGA, then [Patrick] has another series of 17 videos (embedded below) where he goes through the same process using a Digilent BASYS3 FPGA development board. These aren’t your only options — if you just want to understand how it works, without having to build the hardware, then check out the online, browser based implementation of the [Clark Scott] CPU.

If it seems the breadboard build of this 8-bit CPU looks complex, then this
Home Made 8-bit CPU Is A Wiry Blinky Build and a veritable rats nest of jumper wires.

source https://hackaday.com/2021/01/02/build-an-8-bit-cpu-to-know-but-how-do-it-know/

Thirty years ago, [Robert “Buz” Chmielewski] suffered a surfing accident as a teenager. This left him as a quadriplegic due to a C6 spinal cord injury. After becoming a participant in a brain-computer interface study at Johns Hopkins, he was recently able to feed himself through the use of prosthetic arms. The most remarkable thing about these prosthetic arms is primarily the neural link with [Buz’s] brain, which allows him to not only control the artificial arms, but also feel what they are touching, due to a closed-loop system which transfers limb sensory input to the patient’s brain.

The prosthetic limb in question is the Modular Prosthetic Limb (MPL) from Johns Hopkins Applied Physics Laboratory (APL). The Johns Hopkins Medicine Brain-Computer Interface study began a year ago, when [Buz] had six microelectrode arrays (MEA) implanted into his brain: half in the motor cortex and half in the sensory cortex. During the following months, the study focused on using the signals from the first set of arrays to control actuators, such as the MPL. The second set of arrays was used to study how the sensory cortex had to be stimulated to allow a patient to feel the artificial limb much as one feels a biological limb.

What makes this study so interesting is not only the closed-loop approach which provides the patient with feedback on the position and pressure on the prosthetic, but also that it involves both hemispheres of the brain. As a result, after only a year of the study, [Buz] was able to use two of the MPLs simultaneously to feed himself, which is a delicate and complicated tasks.

In the video embedded after the break one can see a comparison of [Buz] at the beginning of the study and today, as he manages to handle cutlery and eat cake, without assistance.

[Thanks for the tip, Qes]

source https://hackaday.com/2021/01/02/how-a-quadriplegic-patient-was-able-to-eat-by-himself-again-using-artificial-limbs/

[Brain] wanted to mark some scissors with his Ortur laser engraver. The problem? The laser won’t cut into the hard metal of the scissors. His solution? Smear the scissors with mustard. No kidding. We’ve heard of this before, and apparently, you can use vinegar, as well, but since the mustard is a paste it is easier to apply. You can see the result in the video, below.

In case you think you don’t need to watch because we’ve already told you the trick, you should know that [Brian] also goes into a lot of detail about preparing single line fonts to get a good result, among a few other tips like improvements to his air assist setup. On a laser cutter, the air assist blows away charred material leaving a clear field of view between the laser and the remaining uncut material. Using a proper air assist can really expand the capabilities of these inexpensive laser cutters — something we recently saw upgraded with a 3D-printed air assist nozzle.

You can buy a commercial marking solution called CerMark Black, but you probably already have mustard. If you are super cheap, you can probably pick up a packet next time you buy a burger somewhere. After all, you don’t need much. Although the video talks about the Ortur, this technique would work with any engraver. We’ve also heard you can do something similar with plaster and alcohol.

source https://hackaday.com/2021/01/02/laser-etching-stainless-steel-with-mustard/

Gesture recognition usually involves some sort of optical system watching your hands, but researchers at UC Berkeley took a different approach. Instead they are monitoring the electrical signals in the forearm that control the muscles, and creating a machine learning model to recognize hand gestures.

The sensor system is a flexible PET armband with 64 electrodes screen printed onto it in silver conductive ink, attached to a standalone AI processing module.  Since everyone’s arm is slightly different, the system needs to be trained for a specific user, but that also means that the specific electrical signals don’t have to be isolated as it learns to recognize patterns.

The challenging part of this is that the patterns don’t remain constant over time, and will change depending on factors such as sweat, arm position,  and even just biological changes. To deal with this the model can update itself on the device over time as the signal changes. Another part of this research that we appreciate is that all the inferencing, training, and updating happens locally on the AI chip in the armband. There is no need to send data to an external device or the “cloud” for processing, updating, or third-party data mining. Unfortunately the research paper with all the details is behind a paywall.

The obvious use case for this technology lies in prosthetics, but it can also be a handy as a general computer input for anyone. Alternative input devices featured heavily in the 2020 Hackaday Prize, including a universal remote for those who suffer from Cerebral Palsy, and Byte, a joystick for your mouth.

 

Thanks for the tip [Qes]!

source https://hackaday.com/2021/01/02/gesture-recognizing-armband/

Like most of us, [Clem] wants to 3D print in metal. Metal 3D printers do exist, but they are generally way out of reach for most of us garage hackers. As an alternative, [Clem] uses a homebrew electroplating system to get prints with a metallic coating.

The setup is quite simple. Small glass jars to act as the plating tanks and the machine uses an Arduino controller along with a PCB to hold things like a relay to control the 24V used for electroplating. To keep everything tidy, [Clem] designed a 3D printed box that stores all the cables and chemicals when you aren’t using them. Since the parts might get hot, the plastic is PETG.

The trick is that parts need to be conductive in order to use electroplating — typically plastic isn’t conductive. [Clem] paints the plastic parts to grant them conductivity. Graphite paint didn’t give great results. However, an iron-based paint worked better but obscures detail on the print. In addition to galvanization (plating with zinc or steel) you can see copper plating of a nail at around the 12 minute mark, with a plastic plating demo a minute later. The machine can even plate gold using an expensive gold-bearing electrolyte. In the video comments, someone also mentioned that it would be interesting to try plating conductive filament without using the paint. [Clem] tried to remove rust from a big part, but the power supply wasn’t up to the task.

Copper plating is often used as a step to make a part conductive so you can then plate with another metal. In addition to copper sulfate, you can use copper acetate. Sometimes, getting metal into fine details can be tough and it is easier to use a pen to plate those areas directly.

source https://hackaday.com/2021/01/01/metal-plating-plastic-or-metal-parts/

When the only tool you have is a hammer, every problem looks like a nail. An LED ornament for the Christmas tree can be built in any manner of simple, easy implementations. You certainly don’t need an ARM Cortex M4 CPU running at 120MHz having a mouthful of three letter features like FPU, ETM, ETB, ECC, RWW, TCM, EIC, AES, CAN bus and much, much more. But [Martin Held] built a super simple LED Christmas tree ornament using the ATSAME51 series micro-controller, which he regularly works with and had on hand, and lots of bi-color LEDs. He already had schematic symbols and programmers for the device from other projects where he uses it more extensively, so putting it all together in time for the festive season was that much faster for him, despite the fact that the micro-controller was most likely the cheapest part of the BOM, besides the passives.

At this point it might be tempting to argue that it would have been so much simpler to use addressable LED’s, such as the WS2812B or the APA102C. You can drive them using a more basic micro-controller, and not require so many GPIO pins. But using such “smart pixel” LED’s for hand assembled prototypes can sometimes lead to unexpected results. If they are not stored in sealed tape/reel form, then storage conditions can have an adverse effect leading to dead pixels. And, they need a specific baking procedure before being soldered. Doing that for a few LEDs at home can be tricky.

So for the LED’s, he again went a bit off the beaten path, selecting to use three different color styles of bi-color LED’s with easy to hand-solder, 1206 footprints. This allows him to get a fairly random mix of colors in the completed ornament.

The LED array is pseudo-charlieplexed. One terminal of each LED goes to a GPIO pin on the micro-controller and the other terminal of all the LED’s are connected to a single complimentary pair of N-channel/P-channel MOSFETs — connected in totem-pole fashion. Depending on which MOSFET is switched on via a GPIO pin driving the gate pin high or low, the second terminal of each LED gets connected to either supply or ground. In combination with the GPIO pins being driven high/low, this allows the bi-color LED to be biased in either direction. Getting each LED to emit one color is simple enough — setting all LED GPIOs low, and MOSFET gate GPIO high will bias the LEDs in one direction. Reverse the GPIO logic, and the LEDs will be biased in the other direction. If this is done slow enough, the two colors can be differentiated easily. If the driving logic is made fast, changing states every 10us, the two separate colors merge to form a third hue. With some clever bit of code, he also adds some randomness in the GPIO output states, resulting in a more appealing twinkling effect. [Martin] does a detailed walk through in the video embedded below.

If you have the same bunch of parts lying around and wish to replicate the project, be warned that the KiCad source files will need some work to clean up errors — [Martin] was in a hurry and knew what he was doing so there are some intentional mistakes in the schematic such as using the same symbol for the N-channel and P-channel MOSFETs, and uni-directional LED symbol in place of the bi-directional one. And for programming, you will need one of these pricey pogo-pin style cables, unless you decide to edit the PCB before sending off the Gerbers.

[Martin] built just three of these bespoke ornaments, retaining one and giving away the other two to a neighbour and a co-worker. But if you would really like to build a tree ornament with addressable LEDs, then check out the Sierpinski Christmas Tree which can be cascaded to form an array of tree ornaments.

source https://hackaday.com/2021/01/01/simple-christmas-tree-christmas-tree-ornament/

There’s nothing quite like a real Christmas tree, but as anyone who’s had one will know there’s also nothing like the quantity of needles that a real tree can shed when it runs short of water. It’s a problem [RK] has tackled, with a Christmas tree water level monitor that has integration with Adafruit’s cloud service to give a handy phone notification when more watering is required.

The real interest in this project lies in the sensor development path. There are multiple ways of water level sensing from floats and switches through resistive and light scattering techniques, but he’s taken the brave step of using a capacitive approach. Water can be used as a dielectric between two parallel metal plates, and the level of the water varies the capacitance. Sadly the water from your tap is also a pretty good conductor, so the first attempt at a capacitive sensor was not effective. This was remedied with a polythene “sock” for each electrode constructed with the help of a heat sealer. The measurement circuit was simply a capacitive divider fed with a square wave, from which an Adafruit Huzzah board could easily derive an amplitude reading that was proportional to the water level. The board then sends its readings to Adafruit.io, from which a message can be sent to a Slack channel with the notification enabled. All in all a very handy solution.

Plant care is a long-running theme in Hackaday projects, but not all of them need a microcontroller.

source https://hackaday.com/2021/01/01/the-internet-of-christmas-tree-watering/

There’s nothing quite like a real Christmas tree, but as anyone who’s had one will know there’s also nothing like the quantity of needles that a real tree can shed when it runs short of water. It’s a problem [RK] has tackled, with a Christmas tree water level monitor that has integration with Adafruit’s cloud service to give a handy phone notification when more watering is required.

The real interest in this project lies in the sensor development path. There are multiple ways of water level sensing from floats and switches through resistive and light scattering techniques, but he’s taken the brave step of using a capacitive approach. Water can be used as a dielectric between two parallel metal plates, and the level of the water varies the capacitance. Sadly the water from your tap is also a pretty good conductor, so the first attempt at a capacitive sensor was not effective. This was remedied with a polythene “sock” for each electrode constructed with the help of a heat sealer. The measurement circuit was simply a capacitive divider fed with a square wave, from which an Adafruit Huzzah board could easily derive an amplitude reading that was proportional to the water level. The board then sends its readings to Adafruit.io, from which a message can be sent to a Slack channel with the notification enabled. All in all a very handy solution.

Plant care is a long-running theme in Hackaday projects, but not all of them need a microcontroller.

source https://hackaday.com/2021/01/01/the-internet-of-christmas-tree-watering/

There’s nothing quite like a real Christmas tree, but as anyone who’s had one will know there’s also nothing like the quantity of needles that a real tree can shed when it runs short of water. It’s a problem [RK] has tackled, with a Christmas tree water level monitor that has integration with Adafruit’s cloud service to give a handy phone notification when more watering is required.

The real interest in this project lies in the sensor development path. There are multiple ways of water level sensing from floats and switches through resistive and light scattering techniques, but he’s taken the brave step of using a capacitive approach. Water can be used as a dielectric between two parallel metal plates, and the level of the water varies the capacitance. Sadly the water from your tap is also a pretty good conductor, so the first attempt at a capacitive sensor was not effective. This was remedied with a polythene “sock” for each electrode constructed with the help of a heat sealer. The measurement circuit was simply a capacitive divider fed with a square wave, from which an Adafruit Huzzah board could easily derive an amplitude reading that was proportional to the water level. The board then sends its readings to Adafruit.io, from which a message can be sent to a Slack channel with the notification enabled. All in all a very handy solution.

Plant care is a long-running theme in Hackaday projects, but not all of them need a microcontroller.

source https://hackaday.com/2021/01/01/the-internet-of-christmas-tree-watering/

Knocking dominoes down is a fun pastime for a rainy afternoon, but setting them all up can be a drag. Thankfully, [Lewis] of [DIY Machines] has built a helpful machine to do the job for you, letting you focus on the fun part instead!

The machine is run by an Arduino Uno, that can be pre-programmed with a layout or controlled over Bluetooth in real time. It uses a geared-down DC motor to drive around a smooth surface, with a servo for steering. A second servo is used to turn a carousel loaded with up to 130 dominoes, allowing the machine to lay long runs without needing a refill. It’s designed to be easy to change so multiple carousels can be printed to quickly run courses of extended lengths.

The build is a great example of a machine capable of doing a tricky task with ease, thanks to 3D printing and smart design. We’re particularly impressed with the simple domino transport mechanism integrated into the drive system without requiring extra motors or servos. It’s not the first domino layer we’ve seen, either. Video after the break.

source https://hackaday.com/2021/01/01/domino-layer-lets-you-focus-on-toppling/

Some of us might solve crossword puzzles or Sudoko games to exercise our minds, but [Nathan Nichols] plays with exotic number systems to keep the brain cells in shape. He wrote the Hanoi C99 library while in high school, implementing several of his favorites.

We have all been using decimal (base 10) and duodecimal (base 12, as in clocks) since before grade school. Us computer geeks are also adept at various computer-friendly systems like binary, octal, and hexadecimal. The true nerds among us will be familiar with systems like vigesimal (base 20 Mayan numerals) and sexagesimal (base 60 Babylonian numbers). We ourselves espoused the virtues of seximal (base 6) a couple of years ago. But if you really want to stretch your mind, take a dive into the weird number systems that [Nathan] has been exploring.

Negabinary (base -2)

The lowest level of weirdness in the group, this one is almost normal. Its the same as binary, except the bit weights have alternating signs: { 0, -2, 4, -8, ... }.

Binarions (base -1+i)

Or base -1+j if you studied electrical engineering. The use of complex numbers as radices was proposed by Donald Knuth way back in 1955. We find it really hard to imagine this one being helpful.

Fibonacci base

Numbers can also be represented by the summation of a sequence of Fibonacci numbers. Using this system, a number can sometimes be represented more than one way, so watch out.

Stern-Brocot tree

A number is represented by its path down the Stern-Brocot tree. One feature of this system is that numbers can be exact. For example, the Stern-Brocot tree representation of one-third has a finite number of digits.

While [Nathan]’s library only performs conversion at input or output, we wonder if someone will take this further and implement an arithmetic unit inside an FPGA. Besides being a fun exercise, it would baffle someone casually trying to reverse engineer your secret calculations. Let us know of any strange number systems you have used or encountered.

source https://hackaday.com/2021/01/01/number-bases-stretch-the-mind/

When flying drones in and around structures, the size of the drone is generally limited by the openings you want to fit through. Researchers at the University of Tokyo got around this problem by using an articulating structure for the drone frame, allowing the drone to transform from a large square to a narrow, elongated form to fit through smaller gaps.

The drone is called DRAGON, which is somehow an acronym for the tongue twisting description “Dual-Rotor Embedded Multilink Robot with the Ability of Multi-Degree-of-Freedom Aerial Transformation“. The drone consists of four segments, with a 2-DOF actuated joint between each segment. A pair of ducted fan motors are attached to the middle of each segment with a 2-DOF gimbal that allows it to direct thrust in any direction relative to the segment. For normal flight the segments would be arranged in the square shape, with minimal movement between the segments. When a small gap is encountered, as demonstrated in the video after the break, the segments rearrange into a dragon-like shape, that can pass through a gap in any plane.

Each segment has its own power source and controller, and the control software required to make everything work together is rather complex. The full research paper is unfortunately behind a paywall. The small diameter of the propellers, and all the added components would be a severe limiting factor in terms of lifting capacity and flight time, but the concept is to definitely interesting.

The idea of shape shifting robots has been around for a while, and can become even more interesting when the different segment can detach and reattach themselves to become modular robots. The 2016 Hackaday Grand Prize winner DTTO is a perfect example of this, although it did lack the ability to fly.

source https://hackaday.com/2021/01/01/transforming-drone-can-be-a-square-or-a-dragon/

Some projects are a rite of passage within their respected fields. For computer science, building one’s own computer from scratch is certainly among those projects. Of course, we’re not talking about buying components online and snapping together a modern x86 machine. We mean building something closer to a fully-programmable 8-bit computer from the ground up, like this one from [Federico] based on 74LS logic chips.

The computer was designed and built from scratch which is impressive enough, but [Federico] completed this project in about a month as well. It can be programmed manually through DIP switches or via a USB connection to another computer, and also includes an adjustable clock which can perform steps anywhere from 1 Hz to 32 kHz. Complete with a 1024 byte memory, a capable ALU, four seven-segment LEDs and (in the second version of the computer) a 2×16 LCD disply, this 8-bit computer has it all.

Not only is this a capable machine designed by someone who clearly knows his way around a logic chip, but [Federico] has also made the code and schematics available on his GitHub page. It’s worth a read even without building your own, but if you want to go that route without printing an enormous PCB you can always follow the breadboard route.

Thanks to [killergeek] for the tip!

source https://hackaday.com/2020/12/31/diy-8-bit-computer-knows-all-the-tricks/

Anyone who has through the process of learning to play a musical instrument for the first time, or listening to someone attempting to do so will know that it can be a rather painful and frustrating experience. [Alessandro Perini] apparently couldn’t get enough of the sound of a first-time musician, so he created a robot to play the melodica badly for hours on end, as demonstrated in the video after the break.

The project is appropriately named “AI’ve just started to learn to play”, and attempts to copy every melody it hears in real-time. The robot consists of the cartridge carriage from an old printer, mounted on a wooden frame to hold the melodica. The original carriage used a DC motor with an encoder for accurate movement, but since position accuracy was not desirable, [Alessandro] ditched the encoder. Two small trolley wheels are mounted on the cartridge holder to push down on the melodica’s key. A bistable solenoid valve controls airflow to the melodica from an air compressor. The DC motor and solenoid valve is controlled by an Arduino via a pair of LM298 motor drivers.

A host computer running software written in Cycling ’74 MAX listens to the melody it’s trying to imitate, and send serial commands to the Arduino to move the carriage and open the solenoid to try and match the notes. Of course, it keeps hitting a series of wrong notes in the process. The Arduino code and build instructions have been published, but the main Max software is only described briefly. [Alessandro] demonstrated the robot at a local festival, where it played YouTube tutorial snippets and jammed with a local band for a full 24 hours. You have to respect that level of endurance.

If listening to less error-prone electronically controlled instruments is more to your taste, listen to this building-sized pipe organ play MIDI files.

source https://hackaday.com/2020/12/31/robotic-melodica-student-is-enthusuastic-but-terrible/

After the year humanity has endured, we could all use a little more relaxation in our lives. This atmosphere lamp is just the thing to set a relaxing ambience for work, studying, or hanging out. Just touch the surface and the light ripples to life, resembling the concentric circles that form on the surface of still water when it is touched. When the light settles, it looks like an inviting pool that’s ready for a nighttime swim.

There aren’t really any surprises inside — the lamp is operated via capsense by touching the center of the top. Three NeoPixel rings and an RGB LED strip provide the lighting, and an Arduino UNO runs the show. [Qttting_F] used an inexpensive ceramic bowl with a piece of acrylic for a lid, but this could just as easily be printed in white PLA or something. Check it out in action after the break.

Ambience is nice, but sometimes you need something more functional. Those types of lamps can be printed, too.

source https://hackaday.com/2020/12/31/ambience-lamp-ripples-like-water/

Hardware hacking can be extremely multidisciplinary. If you only know bits and bytes, but not solder and electrons, you’re limited in what you can build. The same is true for mechanical design, where the forces of stress and strain suddenly apply to your project and the pile of code and PCBs comes crashing to the ground.

In the first half of his workshop, Naman Pushp walks you through some of the important first concepts in mechanical engineering — how to think about the forces in the world that act on physical objects. And he brings along a great range of home-built Jugaad props that include a gravity-defying tensegrity string sculpture and some fancy origami that help hammer the topics home.

In the second half of the workshop, Naman takes these concepts into computer simulation, and gives us good insight into the way that finite-element analysis simulation packages model these same forces on tiny chunks of your project’s geometry to see if it’ll hold up under real world load. The software he uses isn’t free by any definition — it’s not even cheap unless you have a student license — but it’s nonetheless illuminating to watch him work through the flow of roughly designing an object, putting simulated stresses and strains on it, and interpreting the results. If you’ve never used FEA tools before, or are looking for a compressed introduction to first-semester mechanical engineering, this talk might be right up your alley.

Naman is a hacker and student who is currently working on a ridiculously inexpensive laptop-in-a-box for the Indian market, and a drone delivery startup. We’re sure we’ll be hearing more from him in the future.

source https://hackaday.com/2020/12/31/remoticon-video-the-mechanics-of-finite-element-analysis/