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Anansi in African folktale is a trickster and god of stories, usually taking physical form of a spider. Anansi’s adventures through oral tradition have adapted to the situation of people telling those stories, everything ranging from unseasonable weather to living a life in slavery. How might Anansi adapt to the twenty-first century? [odd_jayy] imagined the form of a cyborg spider, and created Asi the robot companion to perch on his shoulder. Anyone who desire their own are invited to visit Asi’s project page.

Asi was inspired by [Alex Glow]’s Archimedes, who also has a project page for anyone to build their own. According to [Alex] at Superconference 2018, she knew of several who have done so, some with their own individual customization. [odd_jayy] loved the idea of a robot companion perched on his shoulder but decided to draw from a different pool of cultural folklore for Asi. Accompanying him to various events like Sparklecon 2019, Asi is always a crowd pleaser wherever they go.

Like every project ever undertaken, there is no shortage of ideas for Asi’s future and [odd_jayy] listed some of them in an interview with [Alex]. (Video after the break.) Adding sound localization components will let Asi face whoever’s speaking nearby. Mechanical articulation for legs would allow more dynamic behaviors while perched, but if the motors are powerful enough, Asi can walk on a surface when not perched. It’s always great to see open source projects inspire even more projects, and watch them as they all evolve in skill and capability. If they all become independently mobile, we’ll need clarification when discussing the average velocity of an unladen folklore robot companion: African or European folklore?

Regular readers of Hackaday have certainly seen the work of [Jeremy Cook] at this point. Whether you remember him from his time as a writer for this fine online publication, or recognize the name from one of his impressive builds over the last few years, he’s a bona fide celebrity around these parts. In fact, he’s so mobbed with fans at events that he’s been forced to employ a robotic companion to handle distributing his personalized buttons for his own safety.

Alright, that might be something of a stretch. But [Jeremy] figured it couldn’t hurt to have an interesting piece of hardware handing out his swag at the recent Palm Bay Mini Maker Faire. Anyone can just put some stickers and buttons in a bowl on a table, but that’s hardly the hacker way. In the video after the break, he walks viewers through the design and construction of this fun gadget, which takes a couple unexpected turns and has contains more than a few useful tips which are worth the cost of admission alone.

Outwardly the 3D printed design is simple enough, and reminds us of those track kits for Matchbox cars. As you might expect, getting the buttons to slide down a printed track was easy enough. Especially when [Jeremy] filed the inside smooth to really get them moving. But the goal was to have a single button get dispensed each time the device was triggered, but that ended up being easier said than done.

The first attempt used magnets actuated by two servos, one to drop the button and the other to hold up the ones queued above it. This worked fine…at first. But [Jeremy] eventually found that as he stacked more buttons up in the track, the magnets weren’t strong enough to hold them back and they started “leaking”. This is an excellent example of how a system can work perfectly during initial testing, but break down once it hits the real world.

In this case, the solution ended up being relatively simple. [Jeremy] kept the two servos controlled by an Arduino and a capacitive sensor, but replaced the magnets with physical levers. The principle is the same, but now the system is strong enough to hold back the combined weight of the buttons in the chute. It did require him to cut into the track after it had already been assembled, but we can’t blame him for not wanting to start over.

Just like the arcade inspired candy dispenser, coming up with a unique way of handing out objects to passerby is an excellent way to turn the ordinary into a memorable event. Maybe for the next iteration he can make it so getting a button requires you to pass a hacker trivia test. Really make them work for it.

Sometimes you have an idea, and despite it not being the “right” time of year you put a creepy skull whose eyes tell the time and whose jaw clacks on the hour into a nice wooden box for your wife as a Christmas present. At least, if you’re reddit user [flyingalbatross1], you do!

The eyes are rotated using 360 degree servos, which makes rotating the eyes based on the time pretty easy. The servos are connected to rods that are epoxied to the spheres used as eyes. Some water slide iris decals are put on the eyes offset from center in order to point in the direction of the minutes/hours. An arduino with a real time clock module keeps track of the time and powers the servos.

Check out the video after the break:

The jaw opens and closes on the hours – springs are screwed to the inside of the jaw to the outside of the skull behind the bones that surround the eyes; they’re hidden when the skull is in its box. A third servo is used as a winch to pull the jaw open from the inside of the bottom of the chin. When it releases, the springs close the mouth and the clack of the teeth replaces an hourly chime.

A bit late (or early) for Halloween, but it’s a really fun project. [Flyingalbatross1] has made the arduino code available, as well as showing plenty of images of how the parts are put together. Take a look at this this atomic clock-in-a-skull, or you make your own talking skull for Halloween!

via Reddit

The junk bin can be a great source of inspiration, unless you’re too familiar with the contents to be imaginative with them. But thrift stores are another matter, like giant junk bins that are constantly replenished by underappreciated elves. You never know what kinds of goodies they will pile on the shelves, so it’s easy to become a fixture and visit them once or thrice a week.

[Hunter Irving] haunts a few choice thrift stores in his neighborhood, and a few months ago he found a knockoff Thomas the Tank Engine with an articulated face. It uses a simple mechanism to produce an impressive amount of movement, especially for a cheap knockoff toy. Both of its eyes slide sideways and its mouth opens, resulting in a very animated (and terrifying) range of expressions. Sensing an opportunity to turn his animatronic robot dreams into karaoke-singing nightmare fuel for the rest of us, he forked over a few bucks and took it home.

As luck would have it, a 9g micro servo fit perfectly in the back of the frightening little face. [Hunter] designed an axle to transfer motion to the face mechanism, but it broke almost immediately. We applaud his Plan B, though, which consists of a mounting block for the servo, and a cable tie armature connected with screws. Once that was sorted, [Hunter] designed a bulbous body for it in Blender.

This terrifying train-faced toy uses an Arduino Leonardo to read MIDI note-on and -off messages, and opens his mouth when appropriate to sing hit favorites in a smooth, speech-synthesized contralto. Pour yourself a strong beverage and enjoy the build/demo video after the break.

Interested in making your own? [Hunter] has all the files up on his Patreon page. For just $1, you can access the code, synth files, and STL files. While you’re there, you can also get the scoop on his Nintendo LABO waveform cards.


These days, photochromic lenses are old-hat. Sure, it’s useful to have a pair of glasses that automatically tints due to UV light, but what if you want something a little more complex and flashy? Enter [Ashraf Minhaj]’s SunGlass-Bot.

The build is simple, beginning with an Arduino Pro Mini for reasons of size. Connected to the analog input is a light-dependent resistor for sensing the ambient light level. This reading is then used to decide whether or not to move the servo which controls the position of the lenses. In low light, the lenses are flipped up to allow clear vision; in brighter light, the lenses flip down to protect the eyes. Power is supplied by a homebrew powerbank that it appears [Ashraf] built from an old phone battery and a small boost converter board. All the files to recreate the project are available on Github, too.

It’s a fun build that [Ashraf] shows off in style. While this may not be as effortless as a set of Transition lenses or as quick as a welding mask filter, it has a certain mechanical charm that wouldn’t be out-of-place in a certain sci-fi aesthetic.

Hungry for more? Check out these self-blending sunglasses we featured a while back. Video after the break.

[NathanKing] has a cute, rambunctious pupper who eats way too fast for her own good. He’s tried various distribution methods intended to get her to slow down, but she’s just too excited to eat. [Nathan]’s latest solution is to launch the food piece by piece using a catapult. The dog loves the gamified feeding method, which is sort of like one-way fetch. She gets a bit of exercise, and everyone is amused for the half hour it takes to fling 1.5 cups of food one piece at a time.

Electronics-wise, this food flinger doesn’t use much more than three servos and an Arduino Uno. Servo #1 pulls the arm back until it hits a limit switch. Servo #2 holds the arm down , and servo #3 rotates the food tube until it drops a unit of kibble into the spoon. Then servo #2 lets the arm go, and the tasty morsel flies about 30 feet (10 meters).

[Nathan] doesn’t offer step-by-step instructions, but there is more than enough detail to replicate this project. He used what he had on hand, such as scrap aluminium from another project for the frame. Future plans include swapping out the 6V lantern battery for rechargeable AAs, and downsizing to a Nano. We’ve fetched a couple of videos for you and thrown them in after the break. Go get ’em, reader!

Pets need plenty of water, especially during the summer. Here’s a no-sweat automatic watering solution we saw a few years ago.

We’re all familiar with the experience of buying hobby servos. The market is awash with cheap clones which have inflated specs and poor performance. Even branded servos often fail to deliver, and sometimes you just can’t get the required torque or speed from the small form factor of the typical hobby servo.

Enter [James Bruton] and his DIY RC servo from a windscreen wiper motor. Windscreen wiper motors are cheap as chips, and a classic salvage. The motor shaft is connected to a potentiometer via a pulley and some string, providing the necessary closed-loop feedback. Instead of using the traditional analog circuitry found inside a servo, an Arduino provides the brains. This means PID control can be implemented on the ‘duino, and tuned to get the best response from different load characteristics. There’s also the choice of different interfacing options: though [James]’ Arduino code accepts PWM signals for a drop-in R/C servo replacement, the addition of a microcontroller means many other input signal types and protocols are available. In fact, we recently wrote about serial bus servos and their numerous advantages.

We particularly love this because of the price barrier of industrial servomotors; sure, this kind of solution doesn’t have the precision or torque that off-the-shelf products provide, but would be sufficient for many hacks. Incidentally, this is what inspired one of our favourite open source projects: ODrive, which focuses on harnessing the power of cheap brushless motors for industrial use. user [peterquinn] has encountered a problem with his recently unruly cat peeing under the dining table. Recognizing that the household cat’s natural enemy is the spray bottle, he built an automatic cat sprayer to deter her antics.

The build is clear-cut: an Arduino Uno clone for a brain, an MG995 servo, PIR sensor, spray bottle, and assorted electronics components. [peterquinn] attached the servo to the spray bottle with a hose clamp — ensuring that the zero position is pointing at the trigger — and running a piece of cabling around the trigger that the servo will tug on. Adding a capacitor proved necessary after frying the first Uno clone, as the servo powering up would cause the Uno to reset.

The code is set up to trigger the servo — spraying the cat twice — once the PIR detects the cat for more than ten seconds. After toying with a few options, [peterquinn] is using a 9V, 2A power supply that works just fine. For now, he hopes the auto-sprayer should do the trick. If it somehow doesn’t work, [peterquinn] has mused that a drastic upgrade to the vacuum may be necessary.

A robot assistant would make the lives of many much easier. Luckily, it’s possible to make one of your own with few fancy materials. The [] team demonstrates this by building a robot arm out of recyclables!

With the exception of the electronics — an Arduino, a trio of servo motors, and a joystick — the arm is made almost completely out of salvaged recyclables: scrap wood, a plastic bottle, bits of plastic string and a spring. Oh, and — demonstrating yet another use for those multi-talented tubers — a potato acts as a counterweight.

Instead of using screws or glue, these hackers used string made from a plastic bottle as a form of heat shrink wrap to bind the parts of the arm together. The gripper has only one pivoting claw for greater strength, and the spring snaps it open once released. Behold: your tea-bag dunking assistant.

Code for the project is available to download from their site. Given this straightforward tutorial, it’s hard to find a reason NOT to embark on building your first robot arm — if you haven’t already begun.

We at Hackaday love seeing projects that strive to reuse materials in inventive ways. That said, you needn’t rely on a shiny new Arduino for this robot arm. If you have an aging palm pilot kicking around, that will also do the trick.

Filed under: Arduino Hacks, hardware, robots hacks

It is pretty easy to go to a big box store and get a digital speedometer for your bike. Not only is that no fun, but the little digital display isn’t going to win you any hacker cred. [AlexGyver] has the answer. Using an Arduino and a servo he built a classic needle speedometer for his bike. It also has a digital display and uses a hall effect sensor to pick up the wheel speed. You can see a video of the project below.

[Alex] talks about the geometry involved, in case your high school math is well into your rear view mirror. The circumference of the wheel is the distance you’ll travel in one revolution. If you know the distance and you know the time, you know the speed and the rest is just conversions to get a numerical speed into an angle on the servo motor. The code is out on GitHub.

Granted, reading a magnet, keeping time, and driving a servo isn’t exactly cutting edge. On the other hand, it made us think about what other kinds of outputs you could drive. We haven’t seen a nixie tube speedometer (well, not on a bicycle, anyway), for example. Or maybe one built with mechanical flip numbers like an old clock.

We have seen some with Arduinos and lots of LEDs (although, again, not really for a bicycle). This speedometer might still be our favorite, though.


Filed under: Arduino Hacks, transportation hacks

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