Like many of us, [Emily’s Electric Oddities] has had a lot of time for projects over the past year or so, including one that had been kicking around since late 2018. It all started at the Hackaday Superconference, when [Emily] encountered the Adafruit Hallowing board in the swag bag. Since that time, [Emily] has wanted to display the example code eyeball movement on a CRT, but didn’t really know how to go about it. Spoiler alert: it works now.
Eventually, [Emily] learned about the TV out library for Arduino and got everything working properly — the eyeball would move around with the joystick, blink when the button is pressed, and the pupil would respond visually to changes in ambient light. The only problem was that the animation moved at a lousy four frames per second. Well, until she got Hackaday’s own [Roger Cheng] involved.
[Roger] was able to streamline the code to align with [Emily]’s dreams, and then it was on to our favorite part of this build — the cabinet design. Since the TV out library is limited to black and white output without shades of gray, Emily took design cues from the late 70s/early 80s, particularly the yellow and wood of the classic PONG cabinet. We love it!
What could be more terrifying than ghosts, goblins, or clowns? How about a shapeless pile of fright on your bedroom floor that only moves when you’re not looking at it? That’s the idea behind [Sciencish]’s nightmare robot, which is lurking after the break. The Minecraft spider outfit is just a Halloween costume.
In this case, “looking at it” equates to you shining a flashlight on it, trying to figure out what’s under the pile of clothes. But here’s the thing — it never moves when light is shining on it. It quickly figures out the direction of the light source and lies in wait. After you give up and turn out the flashlight, it spins around to where the light was and starts moving in that direction.
The brains of this operation is an Arduino Uno, four light-dependent resistors, and a little bit of trigonometry to find the direction of the light source. The robot itself uses two steppers and printed herringbone gears for locomotion. Its chassis has holes in it that accept filament or wire to make a cage that serves two purposes — it makes the robot into more of an amorphous blob under the clothes, and it helps keep clothes from getting twisted up in the wheels. Check out the demo and build video after the break, because this thing is freaky fast and completely creepy.
While we usually see a candy-dispensing machine or two every Halloween, this year has been more about remote delivery systems. Don’t just leave sandwich bags full of fun size candy bars all over your porch, build a candy cannon or a spooky slide instead.
If you’re planning to get into circuit sculpture one of these days, it would probably be best to start with something small and simple, instead of trying to make a crazy light-up spaceship or something with a lot of curves on the first go. A small form factor doesn’t necessarily mean it can’t also be useful. Why not start by making a small automatic night light?
The circuit itself is quite simple, especially because it uses an Arduino. You could accomplish the same thing with a 555, but that’s going to complicate the circuit sculpture part of things a bit. As long as the ambient light level coming in from the light-dependent resistor is low enough, then the two LEDs will be lit.
We love the frosted acrylic panels that [akshar1101] connected together with what looks like right angle header pins. If you wanted to expose the electronics, localize the light diffusion with a little acrylic cover that slips over the LEDs. Check it out in the demo after the break.
Bowling has been around since ancient Egypt and continues to entertain people of all ages, especially once they roll out the fog machine and hit the blacklights. But why pay all that money to don used shoes and drink watered-down beer? Just build a tabletop bowling alley in your spare time and you can bowl barefoot if you want.
Those glowing pins aren’t just for looks — the LEDs underneath them are part of the scoring system. Whenever a pin is knocked out of its countersunk hole, the LED underneath is exposed and shines its light on a corresponding light-dependent resistor positioned overhead. An Arduino Uno keeps track of of the frame, ball number, and score, and displays it on an LCD.
The lane is nearly six feet long, so this is more like medium-format bowling or maybe even skee-bowling. There are probably a number of things one could use for balls, but [lainealison] is using large ball bearings. Roll past the break to see it in action, but don’t go over the line!
Want to make a special Valentine’s Day gift that keeps on giving well past the holiday? We do too, especially if it’s something as cute as [Marcel Stör]’s Lovebox. This is a relatively simple build, but it’s the kind that lets you make someone’s day over and over again.
The sender composes their love note in a secret GitHub gist, either as a text message or a binary image, and updates the gist. Whenever the Wemos D1 mini inside the box receives a new message, a micro servo slowly wiggles the hearts up and down to notify the recipient.
Once they remove the lid to read it, a light-dependent resistor senses the flood of light on its face and tells the servo it can stop wiggling. We think it’s neat that the heart nudges upwardly at the box lid a bit as it moves, because it increases the cuteness factor.
Everybody loves to hear from that special someone throughout the day. The idea of sending an intimate message remotely is quite romantic, and there’s something thrilling and urgent about a physical notification. Show the break button a little love, and you’ll see a truffle-sized demo featuring both an incoming image and a text message.
[Marcel] was happy to ply his woodworking skills rather than use a laser cutter. If you have neither of these, hit up a craft store or two and you’ll find unfinished wooden boxes and pre-cut hearts galore. Or, you could just say it with copper.
A while back, [lonesoulsurfer] stumbled upon a mind-blowing little DIY synth on YouTube and had to make one of his own. We don’t blame him one bit for that, ’cause we’ve been down that cavernous rabbit hole ourselves. You might want to build one too, after you hear the deliciously fat and guttural sounds waiting inside those chips and passives. Don’t say we didn’t warn you.
The main synth is built on five LM358 op-amps that route PWM through a pair of light-dependent resistors installed near the top. There are two more oscillators courtesy of a 40106 hex inverting Schmitt trigger, which leaves four more oscillators to play with should you take the plunge and build your own.
He didn’t just copy the guy’s schematic and call it good. He added [a 555-based arpeggiator that’s controlled with two homebrew optocouplers. These sound fancy and expensive, but can be bred easily at home by sealing an LED and an LDR inside a piece of black heat shrink tubing and applying a bit of PWM. With the flick of a toggle, he can bypass the momentary buttons and use the yellow knob at the top to sweep through the pitch range with a single input.
Although he doesn’t hold your hand through the build, [lonesoulsurfer] has plenty of nice, clear pictures of the process that nearly give a step-by-step guide. That plus the video demo and walk-through should get you well on your way to DIY synthville.
It used to be that time was a lot more relative than it is today. With smartphones synced to GPS and network providers’ clocks, we all pretty much have access to an authoritative current time, giving few of us today the wiggle room to explain a tardy arrival at work to an impatient boss by saying our watch is running slow.
Even when that excuse was plausible, it was a bit weak, since almost every telephone system had some sort of time service. The correct time was but a phone call away, announced at first by live operators then later by machines called speaking clocks. Most of these services had been phased out long ago, but one, the speaking clock service in Australia, sounded for the last time at the end of September.
While the decommissioned machine was just another beige box living in a telco rack, the speaking clocks that preceded it were wonderfully complex electromechanical devices, and perfect fodder for a Retrotechtacular deep-dive. Here’s a look at the Australian speaking clock known as “George” and why speaking clocks were once the highest of technology.