Compact M&M Sorter Goes Anywhere

June 20, 2021 by Kristina Panos 12 Comments

Let’s face it — eating different colored candy like M&Ms or Skittles is just a little more fun if you sort your pile by color first. The not-fun part is having to do it by hand. [Jackofalltrades_] decided to tackle this time-worn problem for engineering class because it’s awesome and it satisfies the project’s requirement for sensing, actuation, and autonomous sequencing. We’d venture to guess that it satisfies [Jackofalltrades_]’ need for chocolate, too.

Here’s how it works: one by one, M&Ms are selected, pulled into a dark chamber for color inspection, and then dispensed into the proper cubby based on the result. [Jackofalltrades_] lived up to their handle and built a color-detecting setup out of an RGB LED and light-dependent resistor. The RGB LED shines red, then, green, then blue at full brightness, and takes a voltage reading from the photocell to figure out the candy’s color. At the beginning, the machine needs one of each color to read in and store as references. Then it can sort the whole bag, comparing each M&M to the reference values and updating them with each new M&M to create a sort of rolling average.

We love the beautiful and compact design of this machine, which was built to maximize the 3D printer as one of the few available tools. The mechanical design is particularly elegant. It cleverly uses stepper-driven rotation and only needs one part to do most of the entire process of isolating each one, passing it into the darkness chamber for color inspection, and then dispensing it into the right section of the jar below. Be sure to check out the demo after the break.

Need a next-level sorter? Here’s one that locates and separates the holy grail of candy-coated chocolate — peanut M&Ms that didn’t get a peanut.

Continue reading “Compact M&M Sorter Goes Anywhere” →

Wood And Brass Drink Temperature Monitor Looks Good, Has Class

June 16, 2021 by Kristina Panos 7 Comments

We’ve all been there. Your current project has hit a wall, or the next step will take days to complete, and you need something to do in the meantime. So you start a project that you envision will fit nicely in the gap, and then, inevitably, it doesn’t. Maybe it even takes so long that the original project gets finished first. So what? There’s nothing wrong with that, especially when the filler project turns out as well as this drink temperature monitor disguised as a circuit sculpture (video, embedded below). Just put your mug on the coaster, and the weight of it activates a hidden switch, which causes the sculpture to display its secret LEDs.

[MakeFunStuff] wanted to make something that looked less like a circuit and more like art, while building a tool that could determine the relative hotness of a beverage. Such a a useful circuit sculpture sounds like a tall order to us, but [MakeFunStuff] pulled it off with finesse and style.

The circuit is based around this Sputnik-looking standalone IR temperature sensor which, as [MakeFunStuff] aptly describes, is “a single-pixel infrared camera that picks up everything in a 90° cone starting at the sensor.”

[MakeFunStuff] paired this easy-to-use sensor with an Arduino Nano and five LEDs that show how hot a beverage is on a scale from 1 to 5. The sensor is hidden in plain sight, suspended from the top of the brass rod sculpture and blending in perfectly. We love that the LEDs are hidden behind a thin layer of carefully-drilled wood and agree that a drill press would have been much easier.

The code is set up for just about every temperature scale from Celsius to Rømer, so that solves that argument. [MakeFunStuff] went with the Kelvin scale because science. Our favorite thing about this video is that [MakeFunStuff] shared their failures and fixes as they built their way toward answering the questions of how to suspend the sensor over the drink, and how best to display the heat level while hiding the electronics. Go grab a hot cup of something and check it out after the break while you let it cool off the normie way.

We admit that we would likely zone out while waiting for the LEDs to disappear. Here’s a smart coaster that uses an ESP8266 to send a message to Discord when your beverage has reached the perfect drinking temperature.

Continue reading “Wood And Brass Drink Temperature Monitor Looks Good, Has Class” →

Sunlight-Based Life Clock Predicts Your Darkest Hour

June 16, 2021 by Kristina Panos 9 Comments

The past year has been quite a ride for everyone on Earth. But you never know which day is going to be your last, so you might as well live a little, eh? This clock doesn’t actually know when you’ll kick off, either. But just for fun, it predicts the number of years remaining until you go to that hackerspace in the sky by hazarding a guess that’s based on your current age and the latest life expectancy tables. Don’t like the outcome? It’s completely randomized, so just push the button and get a set of numbers: the age you might die, and the percentage of life elapsed and remaining.

We love the design of this calculated doom clock, and it’s quite simple inside — an Arduino Pro Mini outputs the graph on an 2.9″ e-paper display, and both are powered with a 5.5 V solar panel. Just suction cup that puppy to the window and you’ll get automatic updates about your impending demise on sunny days, and none on cloudy days.

Want a more realistic picture of your mortality? Here’s a clock that counts down to your 80th birthday.

Cheap, Expandable Floor Piano Plays With Heart And Soul

June 15, 2021 by Kristina Panos 9 Comments

Ever since we saw the movie Big, we’ve wanted a floor piano. Still do, actually. We sometimes wonder how many floor pianos that movie has sold. It’s definitely launched some builds, too, but perhaps none as robust as this acrylic and wooden beauty by [FredTSL]. If you want more technical detail, check out the project on IO.

The best part is that this piano is modular and easily expands from 1 to 8 octaves. Each octave runs on an Arduino Mega, with the first octave set up as a primary and the others as secondaries. When [FredTSL] turns it on, the primary octave sends a message to find out how many octaves are out there, and then it assigns each one a number. Whenever a note is played via conductive fabric and sensor, the program fetches the key number and octave number and sends the message back to the primary Mega, which plays the note through a MIDI music shield.

We think this looks fantastic and super fun to dance around on. Be sure to check out the build log in photos, and stick around after the break, because you’d better believe they busted out some Heart and Soul on this baby. After all, it’s pretty much mandatory at this point.

Wish you could build a floor piano but don’t have the space or woodworking skills? Here’s a smaller, wireless version that was built in 24 hours.

Continue reading “Cheap, Expandable Floor Piano Plays With Heart And Soul” →

Circuit VR: Arduino Virtually Meets Analog

June 11, 2021 by Al Williams 3 Comments

There was a time when building electronics and building software were two distinct activities. These days, almost any significant electronic project will use a CPU somewhere, or — at least — could. Using a circuit simulator can get you part of the way and software simulators abound. But cosimulation — simulating both analog circuits and a running processor — is often only found in high-end simulation products. But I noticed the other day the feature quietly snuck into our favorite Web-based simulator, Falstad.

The classic simulator is on the left and the virtual Arduino is on the right.

Back in March, the main project added work from [Mark McGarry] to support AVR8js written by [Uri Shaked]. The end result is you can have the circuit simulator on the left of the screen and a Web-based Arduino IDE on the right side. But how does it work beyond the simple demo? We wanted to find out.

The screen looks promising. The familiar simulator is to the left and the Arduino IDE — sort of — is to the right. There’s serial output under the source code, but it doesn’t scroll very well, so if you output a lot of serial data, it is hard to read.

Continue reading “Circuit VR: Arduino Virtually Meets Analog” →

Redox Redux: Split Keeb Gets A Num Pad

June 10, 2021 by Kristina Panos 7 Comments

What’s the worst thing about split keyboards? If they have one general fault, it’s that almost none of them have a number pad. If you can fly on that thing, but struggle with using the top row numbers, you will miss the num pad terribly, trust us. So what’s the answer? Design your own keyboard, of course. [ToasterFuel] had enough bread lying around to cook up a little experiment for his first keyboard build, and we think the result is well done, which is kind of rare for first keebs.

This design is based on the Redox, itself a remix of the ErgoDox that aims to address the common complaints about the latter — it’s just too darn big, and the thumb clusters are almost unusable. We love how customized this layout is, with its sprinkling of F keys and Escape in the Caps Lock position. Under those keycaps you’ll find 100% Cherry MX greens, so [ToasterFuel] must have pretty strong fingers to pound those super clackers.

Everything else under the hood is pretty standard, with a pair of Arduino Pro Micros running the show. [ToasterFuel] had to wire up the whole thing by hand because of the num pad, and we’re impressed that he built this entire project in just three weeks. And that includes writing his own firmware!

Already found or built a split you love, but still miss the num pad? Why not build one to match your keyboard?

Custom Num Pad Does Double Duty As Macro Pad

June 8, 2021 by Kristina Panos 7 Comments

Why buy a num pad or a macropad when you can build something new and beautiful, open source that bad boy, and be a hero to the community? We think that should be all the justification you ever need to build instead of buy, even if you think your thing is Just Another Keypad [JAnK] as [Clewsy] claims.

At first glance, JAnK appears to be a standard number pad with four macro keys across the top. But when you roll your own ‘board, all the keys are programmable. [Clewsy] took advantage of this by adding a second layer that’s accessible with (what else?) the Num Lock key. This switches JAnK over to 21-key macro pad mode.

[Clewsy] rolled their own PCB for this and used the venerable ATMega32u4 because of its HID and USB host capabilities. Every key is backlit, and these LEDs are driven by an MP3202 LED driver and PWM from the AVR. [Clewsy] was able to build a prototype by sawing the num pad off of a stainless steel key switch plate from another build, but eventually ordered JAnK its own custom, laser-cut, stainless steel plate. The lovely enclosure is made of spotted gum wood and an acrylic base.

Putting it all together proved to be a bit problematic. [Clewsy] soldered up the minimum viable components for testing and discovered that the ATMega’s VCC and GND pins were both shorted. This killed the AVR programmer, but not the chip itself, and [Clewsy] happened to have a spare. To add insult to injury, the Num Lock light didn’t work, but [Clewsy] was able to simply reverse the LED instead of ordering a new pile of boards. Check out the detailed write-up with code and tons of pictures over on [Clewsy]’s personal site.

One of the awesome things about this build is that [Clewsy] was able to re-use the code from macr0, which began life as a proof of concept for scanning key matrices, and retired to become a music and media controller.