Dream Bigger, Predict The Future

I’d love to tell you that I’m never wrong, but I’ve been wrong a lot. Remember the Arduino? When it was brand new, I thought it was some silly collection of libraries and a drop-down menu for people who are too lazy to just type out their own #include statements. Needless to say, it launched about a million hacks and brought microcontroller programming into the mainstream. Oops.

Similarly, about fifteen years ago, I saw an educational project out of MIT’s Media Lab. It consisted of a bunch of blocks that had LCD screens on them and would interact with each other when put together. The real hook, though, was that each block had an accelerometer inside, so you could “pour water” out of one block into another, for instance.

At that time, accelerometers were expensive, even in quantities. Even one of these cubes must have cost $100 at the time, much less a whole set. Accelerometers were so expensive that I wouldn’t have thought about incorporating one into a project, much less a dozen, so I ignored them for hacker purposes. Then came the cellphone and economies of scale. Today, even in chip shortage times, they’re readily available for around $2 each, making them useful for exactly this kind of “frivolous” use.

From the Arduino experience, I learned to never underestimate the impact of what seem to me to be “small” conveniences. (And maybe more so, the value of the tremendous common effort from the community.) From the MIT accelerometer story, the moral is that some parts will get drastically cheaper in the future, so you shouldn’t necessarily exclude the cool new sensor from your design repertoire. After all, ten years ago, nobody would have thought that we’d have laser time-of-flight rangefinders for less than a hamburger.

What new components are fantastically useful, or full of potential, that might be cheap enough in the future to make them also worth looking into? Swing by Hackaday tomorrow morning and join in the conversation!

Skeleton Watches You Intensely Because It’s Halloween, Okay

If you’ve ever seen a painting in which the eyes follow you around the room, you might have found that a bit uneasy. [CuriousInventor] has taken that concept further with a skeleton that literally holds a gaze on anyone in its field of view. 

The heart of the system is a Raspberry Pi Zero, fitted with a Pi Camera. Running OpenCV, code is set up to track humans and turn the skeleton’s head to face any that are detected. This is achieved via a servo in the skeleton’s neck. A servo bonnet is used to drive the servos without unnecessarily straining the Raspberry Pi.

The skeleton itself doesn’t look modified in any way, though most of the electronics are mounted inside a pretty obvious plastic box. We’d love to see a version 2 with all the hardware housed neatly inside the skull.

It’s a fun hack that makes for an enjoyable Halloween decoration. OpenCV can do other useful things, too, however, like spotting weeds. Video after the break.

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Cheap Caliper Hack Keeps ‘Em Running Longer

Many a hacker is a fan of the cheapest calipers on the market. Manufactured in China and priced low enough that they’re virtually disposable, they get a lot of jobs done in the world where clinical accuracy isn’t required. However, their batteries often die when left in a drawer for a long time. [Ben] was sick of that, and got to hacking.

The result was a quick-and-dirty mod that allows the calipers to be powered by a AAA battery. The average AAA cell has 5-10 times the capacity of the typical LR44 coin cells used in these devices.

[Ben] whipped this up with an eye to making it work rather than making it nice, so there are some shortcuts taken. The battery housing was 3D-printed on the lowest-quality settings that were viable, and it’s held to the calipers with hot glue. Similarly, bare wire ends were used instead of proper contacts, taking advantage of the battery being crammed in to make a good connection.

It’s a hack that will likely save [Ben] much frustration, as he’ll now rarely open his drawer to find his calipers dead. However, one [Pete Prodoehl] suggests another useful trick: store the calipers in the closed position with the lock screw tight to save them turning themselves on accidentally.

Whichever way you go, you’ve hopefully learned something today that will keep your cheap calipers working when you need them. Next, you might consider hacking them to capture data, too.

EMC Tutorial Puts You In The Loop

A student once asked his lab instructor why his amplifier was oscillating. After looking at it and noting the wild construction, the instructor remarked, “A better question would be why shouldn’t it oscillate?” The truth of it is, our circuits generate noise and especially if they are oscillating anyway. Distortion and nonlinearities generate harmonics and other component imperfections also contribute.

[FesZ Electronics] has a great video series about noise in switching power supplies and the latest talks about the hot loop. If you want to improve the noise performance of your next design, these videos are well worth watching. You can see the hot loop video below.

We really liked the homebrew noise probes. In addition to real-world probing. The video also observes circuit operation under simulation. Even if you don’t care about noise performance, there’s a lot of good information about basic switching power supply design here.

You can see the difference in a PCB that has a small hot loop versus a very small hot loop. Something to think about next time you are laying out a power supply board.

If you want to dive deeper into noise simulation, we have a good read on that for you. Or ditch simulation, and make your own cheap probe with an SDR dongle.

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This Eyeball Watches You Thanks To Kinect Tracking

Eyeballs are often watching us, but they’re usually embedded in the skull of another human or animal. When they’re staring at you by themselves, they can be altogether more creepy. This Halloween project from [allpartscombined] aims to elicit that exact spooky vibe.

The project relies on a Kinect V2 to do body tracking. It feeds data to a Unity app that figures out how to aim the eyeball at any humans detected in the scene. The app sends angle data to an Arduino over serial, with the microcontroller generating the necessary signals to command servos which move the eyeball.

With tilt and pan servos fitted and the precision tracking from the Kinect data, the eye can be aimed at people  in two dimensions. It’s significantly spookier than simply panning the eye back and forth.

The build was actually created by modifying an earlier project to create an airsoft turret, something we’ve seen a few times around these parts. Fundamentally, the tracking part is the same, just in this case, the eye doesn’t shoot at people… yet! Video after the break.

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Pomodoro timer helps you focus on tasks without burning out.

World’s Cutest Pomodoro Timer Is Also A Clock

Student and hacker [prusteen] recently fell in love with the Pomodoro method of time management. That’s where you concentrate on your task for 25 minutes, then take a five-minute break, and repeat this four times with a longer break at the end. Initially, [prusteen] was keeping track on their phone, but hated having to change the timer value between Pomodoros and break times. In order to keep the flow mode engaged, [prusteen] came up with this darling little study buddy that does it all with the push of a button.

By default, this tomato shows the current time, which we think is a handy and often-overlooked feature of Pomodoro timer builds. Press that momentary switch on the front, and it starts counting upward to 25 minutes. Then it beeps in stereo through a pair of buzzers when the time is up, and automatically starts a five-minute break timer. Press it again and the display goes back to clock mode, although judging by the code, doing this will cancel the timer.

Inside the juicy enclosure is an Arduino Nano, an RTC, and a 7-segment display. We love the attention to detail here, from the little green leaves on top to the anatomically-correct dimple on the underside. And we always like to see lids that snap on with magnets. So satisfying. Check out the brief demo after the break, which unfortunately does not include any lid-snapping action.

Do you need more interaction with your Pomodoro timer? Build yourself a pomo-dachi instead.

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An animated newspaper image from Harry Potter

Muggle Uses E-Paper For Daily Prophet Replica

News from the wizarding world is a little hard to come by for common muggles, but [Deep Tronix] has brought us one step closer to our magical counterparts with their electronic replica of the Daily Prophet newspaper.

Those familiar with the Harry Potter series will no doubt be familiar with the Daily Prophet. In the films, the newspaper is especially eye-catching with its spooky animated images, a reflection of the magic present throughout the wizarding world. This was achieved with post-production special effects for the films, but this fan-made front page of the Prophet brings the concept to life using e-paper technology and a few other interesting gadgets, all hidden away in a picture frame.

As mentioned, the heart of this project is the e-paper display and a Teensy microcontroller. While e-paper displays are excellent for displaying static text and simple graphics, they are usually not suitable for moving images due to suffering from a form of ‘burn in’, which can leave errant pixels on the screen. This means that e-paper technology typically has a relatively low frame rate for video. [Deep Tronix] has used a custom dithering library to somewhat mitigate this issue, and the results are impressive. Moving images are loaded from an external SD card, processed, and then displayed on the e-paper display, which is almost indistinguishable from the newspaper print that surrounds it.

The seemingly magical newspaper also has a face detection feature, which is enabled by a hidden camera and the venerable ESP32 microcontroller. This system integrates with the Teensy to record and then display the reader’s face on the e-paper display. A neat trick, which is made all the more eerie when these faces are later displayed at random.

We’ve seen Daily Prophet replicas before using more traditional display technology, however the move to an e-paper display goes a long way to improving the overall aesthetics, despite the lower frame rates. With Halloween just around the corner, you might just end up tricking a few people with this clever prop – check out all the build details here.

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