Random Numbers From Outer Space

January 20, 2020 by Kristina Panos 22 Comments

Need a random number? Sure, you could just roll a die, but if you do, you might invite laughter from nearby quantum enthusiasts. If it’s truly, unpredictably random numbers you need, look no farther than the background radiation constantly bombarding us from the safety of its celestial hideout.

In a rare but much appreciated break from the Nixie tube norm of clock making, [Alpha-Phoenix] has designed a muon-powered random number generator around that warm, vintage glow. Muons are subatomic particles that are like electrons, but much heavier, and are created when pions enter the atmosphere and undergo radioactive decay. The Geiger-Müller tube, mainstay of Geiger counters the world over, detects these incoming muons and uses them to generate the number.

Inside the box, a 555 in astable mode drives a decade counter, which outputs the numbers 0-9 sequentially on the Nixie via beefy transistors. While the G-M tube waits for muons, the numbers just cycle through repeatedly, looking pretty. When a muon hits the tube, a second 555 tells the decade counter to stop immediately. Bingo, you have your random number! The only trouble we can see with this method is that if you need a number right away, you might have to go get a banana and wave it near the G-M tube.

Whether this all makes sense or not, you should check out [Alpha-Phoenix]’s project video, which is as entertaining as it is informative. He’s planning a follow-up video focused on the randomness of the G-M tube, so look out for that.

Looking for a cheaper way to catch your random numbers? You can do it with a fish tank, some air pumps, and a sprinkle of OpenCV.

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Make A Mean-Sounding Synth From Average Components

January 14, 2020 by Kristina Panos 12 Comments

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.

If this all seems very cool, but you’d really like to understand what’s happening as you descend into the rabbit hole, our own [Elliot Williams]’s Logic Noise series is an excellent start.

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Drive A Plasma Ball With An ATV Ignition Coil And A 555

December 9, 2019 by Gerrit Coetzee 7 Comments

[Discrete Electronics Guy] sends in his short tutorial on building a high voltage power supply from simple things.

The circuit is a classic, but we love the resourcefulness shown. The ignition coil comes from a three wheeler, the primary power supply is a ATX supply from a computer and the oscillator is powered by a 9V battery. We do wonder whose vehicle stopped working though.

He gives a great explanation of how the circuit works and was constructed and then moves on to build his own Plasma bulb. Despite expecting something more complicated the end result was achieved by putting a lightbulb on a stick. Fantastic. The circuitry was nearly packaged into a takeaway food container and the entire construction was called complete.

All in all it shows what someone can accomplish if they’re resourceful and understand the basics. However, it’s probably that you don’t electroBoom yourself to death if you can avoid it.

Guitar Effect Built From An Old Record Player

December 9, 2019 by Tom Nardi 4 Comments

With little more than a gutted record player, a light bulb, and the legendary 555 timer IC, [Jacob Ellzey] has constructed this very slick optical tremolo effect for his guitar. By modulating the volume of the input signal, the device creates the wavering effect demonstrated in the video after the break.

The key is a vinyl record with large tabs cut out of it. As the record spins, these voids alternately block and unblock a small incandescent bulb. A common GL5537 photoresistor, mounted on the arm that originally held the player’s needle, picks up the varying light levels and passes that on to the electronics underneath the deck. An important note here is that different spacing and sizing of the cutouts will change the sound produced by the effect. [Jacob] has already produced a few different designs and plans on experimenting with more now that the electronics are completed.

Under the hood there’s a voltage divider and low gain amplifier connected to the photoresistor, and also a 555 timer circuit that’s driving the incandescent bulb. Once he was done fiddling with them, the circuit was moved to a neat little protoboard. A pair of potentiometers mounted through the side of the record player allow for adjusting the depth of the effect itself, as well as the output volume. Naturally, there’s also an external foot pedal that allows keying the effect on and off without taking your hands from the guitar.

As is usually the case, everything was going well on this project until the final moments, when [Jacob] found that the circuit and bulb were both browning out when powered from the same transformer. As a quick fix, he gutted a Keurig and used its transformer to drive the light bulb by itself. With independent power supplies, he was ready to rock.

Of course this isn’t the first time we’ve seen a piece of consumer electronics modified into a guitar effect, but if you’re looking for something a bit more built for purpose, there’s plenty of high-tech options to keep you busy.

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Hackaday Podcast 042: Capacitive Earthquakes, GRBL On ESP32, Solenoid Engines, And The TI-99 Space Program

November 1, 2019 by Mike Szczys 3 Comments

Hackaday Editors Elliot Williams and Mike Szczys talk turkey on the latest hacks. Random numbers, art, and electronic geekery combine into an entropic masterpiece. We saw Bart Dring bring new life to a cool little multi-pen plotter from the Atari age. Researchers at UCSD built a very very very slow soft robot, and a broken retrocomputer got a good dose of the space age. A 555 is sensing earthquakes, there’s an electric motor that wants to drop into any vehicle, and did you know someone used to have to read the current time into the telephone ad nauseam?

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 042: Capacitive Earthquakes, GRBL On ESP32, Solenoid Engines, And The TI-99 Space Program” →

Simple Seismic Sensor Makes Earthquake Detection Personal

October 28, 2019 by Dan Maloney 6 Comments

When an earthquake strikes, it’s usually hard to miss. At least that’s the case with the big ones; the dozens or hundreds of little quakes that go largely unnoticed every day are interesting too, and make sense to track. That’s usually left to the professionals, with racks of sensitive equipment and a far-flung network of seismic sensors. That doesn’t mean you can’t keep track of doings below your feet yourself, with something like this DIY seismograph.

Technically, what [Alex] built is better called a “seismic detector” since it’s not calibrated in any way. It’s just a simple sensor for detecting ground vibrations, whether they be due to passing trucks or The Big One. [Alex] lives in California, wedged between the Hayward, Calaveras, and San Andreas faults in San Jose, so there is plenty of opportunity for testing his device. The business end is a simple pendulum sensor, with a heavy metal bob hanging from a long wire inside a length of plastic pipe. Positioned close to the bob is a copper plate; the bob and the plate form an air-dielectric variable capacitor that controls the frequency of a simple 555 oscillator. The frequency is measured by a PIC microcontroller and sent to a Raspberry Pi, which displays the data on a graph. You can check in on real-time seismic activity in San Jose using the link above, or check out historical quakes, like the 7.1 magnitude Ridgecrest quake in July. [Alex]’s sensor is sensitive enough to pick up recent quakes in Peru, Fiji, and Nevada, and he even has some examples of visualizing the Earth’s core using data from the sensor. How cool is that?

We’ve seen other seismic detectors before, like this piezo-based device, or even one made from toilet parts. We like the simplicity of the capacitive sensor [Alex] used, though.

DIY Clapper Lets You Pick Your Components

October 6, 2019 by Al Williams 4 Comments

One thing that always means the end of the year is close is the reappearance of TV ads for “The Clapper.” After all, who needs home automation when you can clap on and clap off? While we’re partial to our usual home automation solutions, [Utsource123] shows us that building a clapper can be a fun and easy project using several similar circuits. One with a few transistors and another one with a 555 because, after all, what can’t a 555 do?

Of course, these circuits usually have a microphone. We were trying to think of how you could make a sound-sensitive element out of common parts. After all, you don’t care about the fidelity of the microphone pickup, just that it hears a loud noise. The circuits are about what you’d expect. The transistor version uses one to amplify the microphone and another to switch on the LED. You’d need a bit more to trigger a relay. The 555 uses an even simpler preamp transistor as a trigger.

While we aren’t bowled over with the idea of a clapper, we imagine these circuits aren’t far removed from the ones you buy in stores. For about $16 you also get enough switching to handle a simple AC load, though. Maybe Alexa and Google should allow making clapping a wake up word?

This is sure simpler than the last clapper clone we saw. Then there’s the deluxe DIY version.