Decorative Light Box Lets You Guess The Time

October 19, 2018 by 7 Comments

Telling time by using the current position of the sun is nothing revolutionary — though it probably was quite the “life hack” back in ancient times, we can assume. On the other hand, showing time by using the current position of the sun is what inspired [Rich Nelson] to create the Day Cycle Clock, a color changing light box of the Philadelphia skyline, simulating a full day and night cycle in real time — servo-controlled sun and moon included.

At its core, the clock uses an Arduino with a real-time clock module, and the TimeLord library to determine the sunrise and sunset times, as well as the current moon phase, based on a given location. The sun and moon are displayed on a 1.44″ LCD which doubles as actual digital clock in case you need a more accurate time telling after all. [Rich] generally went out of his way with planning and attention to detail in this project, as you can see in the linked video, resulting in an impressively clean build surely worthy as gift to his brother. And if you want to build one for yourself, both the Arduino source code and all the mechanical parts are available on GitHub.

An interesting next iteration could be adding internet connectivity to get the current weather situation mixed into the light behavior — not that it would be the first time we’d see weather represented by light. And of course, simulating the northern lights is also always an option.

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Redeem Your Irresponsible 90s Self

October 18, 2018 by 5 Comments

If you were a youth in the 90s, odds are good that you were a part of the virtual pet fad and had your very own beeping Tamagotchi to take care of, much to the chagrin of your parents. Without the appropriate amout of attention each day, the pets could become sick or die, and the only way to prevent this was to sneak the toy into class and hope it didn’t make too much noise. A more responsible solution to this problem would have been to build something to take care of your virtual pet for you.

An art installation in Moscow is using an Arduino to take care of five Tamagotchis simultaneously in a virtal farm of sorts. The system is directly wired to all five toys to simulate button presses, and behaves ideally to make sure all the digital animals are properly cared for. Although no source code is provided, it seems to have some sort of machine learning capability in order to best care for all five pets at the same time. The system also prints out the statuses on a thermal printer, so you can check up on the history of all of the animals.

The popularity of these toys leads to a lot of in-depth investigation of what really goes on inside them, and a lot of other modifications to the original units and to the software. You can get a complete ROM dump of one, build a giant one, or even take care of an infinite number of them. Who would have thought a passing fad would have so much hackability?

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The Math That Makes Computers Go, Built On A Tiny PCB

October 18, 2018 by 20 Comments

A computer is, at its core, just a bunch of transistors wired together. Once you have enough transistors on a board, though, one of the first layers of abstraction that arises is the Arithmetic Logic Unit. The ALU takes in two sets of data, performs a chosen math function, and outputs one data set as the result. It really is the core of what makes computers compute.

An ALU is built into modern processors, but that wasn’t always how it was done. If you’re looking to build a recreation of an early computer you may need a standalone, and that’s why [roelh] designed an ALU that fits in a square inch piece of circuit board using five multiplexer chips and two XOR chips.

One of the commonly used components for this purpose, the 74LS181 ALU, is not in production anymore. [roelh’s] ALU is intended to be a small footprint replacement of sorts, and can perform seven functions: ADD, SUB, XOR, XNOR, AND, OR, A, B, and NOT A. The small footprint for the design is a constraint of our recent contest: Return of the Square Inch Project. Of course, this meant extra design challenges, such as needing to move the carry in and carry out lines to a separate header because there wasn’t enough space on one edge.

Exploring the theory behind an ALU isn’t just for people building retrocomputers. It is integral to gaining an intuitive understanding of how all computers work. Everyone should consider looking under the hood by walking through the nand2tetris course which uses simulation to build from a NAND gate all the way up to a functioning computer based on The Elements of Computing Science textbook.

If you’re a homebrew computer builder, it might be worthwhile to use one of these ALUs rather than designing your own. Of course, if building components from scratch is your thing we definitely understand that motivation as well.

Playing Doom On Keysight Oscilloscope Via Windows CE

October 18, 2018 by 22 Comments

We all know the drill when buying a digital oscilloscope: buy the most hackable model. Some choose to void the warranty right away and access features for which the manufacturer has kindly provided all the hardware and software but has disabled through licensing. Few of us choose to tap into the underlying embedded OS, though, which seems a shame.

When [Jason Gin]’s scope started giving him hints about its true nature, he decided to find a way in. The result? An oscilloscope with a Windows desktop that plays Doom. The instrument is a Keysight DSOX1102G which [Jason] won during the company’s “Scope Month” giveaway. Relatively rare system crashes showed the familiar UI trappings of Windows CE.

Try as he might, [Jason] couldn’t get the scope to crash on cue — at least not until he tried leaving an external floppy drive plugged into the USB port on startup. But in order to use the desktop thus revealed, a keyboard and mouse were needed too. So he whipped up a custom USB switch cable, to rapidly toggle in the keyboard and mouse after the crash. This gave him the keys to the kingdom, but he still had a long way to go. We won’t spoil the story, but suffice it to say that it took [Jason] a year and a half, and he learned a lot along the way.

It was nice to hear that our review of the 1000X series scopes helped [Jason] accomplish this exploit. This hack’s great for bragging rights, as one way to prove you’ve owned a system is telling people it runs Doom!

SandBot Happily And Tirelessly Rolls Patterns In Sand

October 18, 2018 by 1 Comment

The patience and precision involved with drawing geometric patterns in sand is right up a robot’s alley, and demonstrating this is [rob dobson]’s SandBot, a robot that draws patterns thanks to an arm with a magnetically coupled ball.

SandBot, SCARA version. The device sits underneath a sand bed, and a magnet (seen at the very top at the end of the folded “arm”) moves a ball bearing through sand.

SandBot is not a cartesian XY design. An XY frame would need to be at least as big as the sand table itself, but a SCARA arm can be much more compact. Sandbot also makes heavy use of 3D printing and laser-cut acrylic pieces, with no need of an external frame.

[rob]’s writeup is chock full of excellent detail and illustrations, and makes an excellent read. His previous SandBot design is also worth checking out, as it contains all kinds of practical details like what size of ball bearing is best for drawing in fine sand (between 15 and 20 mm diameter, it turns out. Too small and motion is jerky as the ball catches on sand grains, and too large and there is noticeable lag in movement.) Design files for the SCARA SandBot are on GitHub but [rob] has handy links to everything in his writeup for easy reference.

Sand and robots (or any moving parts) aren’t exactly a natural combination, but that hasn’t stopped anyone. We’ve seen Clearwalker stride along the beach, and the Sand Drawing Robot lowers an appendage to carve out messages in the sand while rolling along.

Laser Cut Cardboard Robot Construction Kit Eases Learning And Play

October 18, 2018 by No comments

It has never been easier to put a microcontroller and other electronics into a simple project, and that has tremendous learning potential. But when it comes to mechanical build elements like enclosures, frames, and connectors, things haven’t quite kept the same pace. It’s easier to source economical servos, motors, and microcontroller boards than it is to arrange for other robot parts that allow for cheap and accessible customization and experimentation.

That’s where [Andy Forest] comes in with the Laser Cut Cardboard Robot Construction Kit, which started at STEAMLabs, a non-profit community makerspace in Toronto. The design makes modular frames, enclosures, and basic hardware out of laser-cut corrugated cardboard. It’s an economical and effective method of creating the mechanical elements needed for creating robots and animatronics while still allowing easy customizing. The sheets have punch-out sections for plastic straws, chopstick axles, SG90 servo motors, and of course, anything that’s missing can be easily added with hot glue or cut out with a knife. In addition to the designs being open sourced, there is also an activity guide for educators that gives visual examples of different ways to use everything.

Cardboard makes a great prototyping material, but what makes the whole project sing is the way the designs allow for easy modification and play while being easy to source and produce.

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Ask Hackaday: Why Aren’t We Hacking Cellphones?

October 18, 2018 by 148 Comments

When a project has outgrown using a small microcontroller, almost everyone reaches for a single-board computer — with the Raspberry Pi being the poster child. But doing so leaves you stuck with essentially a headless Linux server: a brain in a jar when what you want is a Swiss Army knife.

It would be a lot more fun if it had a screen attached, and of course the market is filled with options on that front. Then there’s the issue of designing a human interface: touch screens are all the rage these days, so why not buy a screen with a touch interface too? Audio in and out would be great, as would other random peripherals like accelerometers, WiFi, and maybe even a cellular radio when out of WiFi range. Maybe Bluetooth? Oh heck, let’s throw in a video camera and high-powered LED just for fun. Sounds like a Raspberry Pi killer!

And this development platform should be cheap, or better yet, free. Free like any one of the old cell phones that sit piled up in my “hack me” box in the closet, instead of getting put to work in projects. While I cobble together projects out of Pi Zeros and lame TFT LCD screens, the advanced functionality of these phones sits gathering dust. And I’m not alone.

Why is this? Why don’t we see a lot more projects based around the use of old cellphones? They’re abundant, cheap, feature-rich, and powerful. For me, there’s two giant hurdles to overcome: the hardware and the software. I’m going to run down what I see as the problems with using cell phones as hacker tools, but I’d love to be proven wrong. Hence the “Ask Hackaday”: why don’t we see more projects that re-use smartphones?

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