Blinking LEDs For A Timeless Fountain

We’ve seen a few of these builds before, but the build quality of [Mathieu]’s timeless fountain makes for an excellent display of mechanical skill showing off the wonder of blinking LEDs.

This timeless fountain is something we’ve seen before, and the idea is actually pretty simple: put some LEDs next to a dripping faucet, time the LEDs to the rate at which the droplets fall, and you get a stroboscopic effect that makes tiny droplets of water appear to hover in mid-air.

Like earlier builds, [Mathieu] is using UV LEDs and is coloring the water with fluorescein, a UV reactive dye. The LEDs are mounted on two towers, and at the top of the tower is a tiny, low power IR laser and photodiode. With the right code running on an ATxmega16A4, the lights blink in time with the falling water droplet, making it appear the drop is hovering in midair.

Blinking LEDs very, very quickly isn’t exactly hard. The biggest problem with this build was the mechanics. The frame of the machine was machined out of polycarbonate sheets and went together very easily. Getting a consistent drip from a faucet was a bit harder. It took about fifteen tries to get the design of the faucet nozzle right, but [Mathieu] eventually settled on a small output hole (about 0.5 mm) and a sharp nozzle angle of about 70 degrees.

[Mathieu] created a video of a few hovering balls of fluorescence. You can check that out below. It’s assuredly a lot cooler in real life without frame rate issues.

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Hackaday Prize Entry: Ultimate Circuitbending

Circuit bending is the process of taking a small electronic toy or musical instrument, soldering wires to pads on the PCB, and hoping the sounds it produces will be cool. It’s not a science by any means, and any good, weird sounds you’ll get out of a Speak ‘N Spell or old MIDI keyboard are made entirely by accident or hours and hours of experimentation.

[Alpha Charlie]’s entry for the Hackaday Prize is the most technologically advanced circuit bending you’ll ever see. He’s using an old digital beat box, the Roland TR-626, with computer-controlled wires between random pads on the PCB.

Until now, you could tell how technically adept a circuit bender was simply by how many switches were on the circuit-bent instrument. [Alpha Charlie] doesn’t need switches. Instead, he’s using a few crosspoint switch ICs to connect different pins and pads on the TR-626’s PCB with an Arduino. All of this is controlled by a touchscreen display, and experimenting with the circuit is as simple as pushing a few buttons. Each ‘bend’ is computer controlled, and can be saved and recalled at will.

Of course, circuit bending doesn’t do anyone any good if it sounds like crap. [Alpha Charlie] doesn’t have to worry there. In the video below, he’s getting some very unique sounds that sound like a choir of angels to dorks like myself that listen to Nintendo music.

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Brass Clock Face Etched With PCB Techniques

Over the last few months, [Chris] has been machining a timepiece out of brass and documenting the entire process on his YouTube channel. This week, he completed the clock face. The clock he’s replicating comes from a time before CNC, and according to [Chris], the work of engraving roman numerals on a piece of brass would have been sent out to an engraver. Instead of doing things the traditional way, he’s etching brass with ferric chloride. It’s truly artisan work, and also provides a great tutorial for etching PCBs.

[Chris] is using a photoresist process for engraving his clock dial, and just like making PCBs, this task begins by thoroughly scrubbing and cleaning some brass with acetone. The photoresist is placed on the brass, a transparency sheet printed off, and the entire thing exposed to four blacklights. After that, the unexposed photoresist is dissolved with a sodium carbonate solution, and it’s time for etching.

The clock face was etched in ferric chloride far longer than any PCB would; [Chris] is filling these etchings with shellac wax for a nice contrast between the silvered brass and needs deep, well-defined voids.

You can check out the video below, but that would do [Chris]’ channel a disservice. When we first noticed his work, the comments were actually more positive than not. That’s high praise around here.

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Hackaday Prize Entry: Multispectral Imaging Based On LandSat 7

The Landsat series of earth observing satellites is one of the most successful space programs in history. Millions of images of the Earth have been captured by Landsat satellites, and those images have been put to use for fields as divers as agriculture, forestry, cartography, and geology. This is only possible because of the science equipment on these satellites. These cameras capture a half-dozen or so spectra in red, green, blue, and a few bands of infrared to tell farmers when to plant, give governments an idea of where to send resources, and provide scientists the data they need.

There is a problem with satellite-based observation; you can’t take a picture of the same plot of land every day. Satellites are constrained by Newton, and if you want frequently updated, multispectral images of a plot of land, a UAV is the way to go.

[SouthMade]’s entry for the Hackaday Prize, uSenseCam, does just that. When this open source multispectral camera array is strapped to a UAV, it will be able to take pictures of a plot of land at wavelengths from 400nm to 950nm. Since it’s on a UAV and not hundreds of miles above our heads, the spacial resolution is vastly improved. Where the best Landsat images have a resolution of 15m/pixel, these cameras can get right down to ground level.

Like just about every project involving imaging, the [SouthMade] team is relying on off-the-shelf camera modules designed for cell phones. Right now they’re working on an enclosure that will allow multiple cameras to be ganged together and have custom filters installed.

While the project itself is just a few cameras in a custom enclosure, it does address a pressing issue. We already have UAVs and the equipment to autonomously monitor fields and forests. We’re working on the legality of it, too. We don’t have the tools that would allow these flying robots to do the useful things we would expect, and hopefully this project is a step in the right direction.


The 2015 Hackaday Prize is sponsored by:

Discrete Transistor Computer Is Not Discreet

Every few years, we hear about someone building a computer from first principles. This doesn’t mean getting a 6502 or Z80, wiring it up, and running BASIC. I’m talking about builds from the ground up, starting with logic chips or even just transistors.

[James Newman]’s 16-bit CPU built from transistors is something he’s been working on for a little under a year now, and it’s shaping up to be one of the most impressive computer builds since the days of Cray and Control Data Corporation.

The 10,000 foot view of this computer is a machine with a 16-bit data bus, a 16-bit address bus, all built out of individual circuit boards containing single OR, AND, XOR gates, decoders, multiplexers, and registers.  These modules are laid out on 2×1.5 meter frames, each of them containing a schematic of the computer printed out with a plotter. The individual circuit modules sit right on top of this schematic, and if you have enough time on your hands, you can trace out every signal in this computer.

The architecture of the computer is more or less the same as any 16-bit processor. Three are four general purpose registers, a 16 bit program counter, a stack pointer, and a status register. [James] already has an assembler and simulator, and the instruction set is more or less what you would expect from a basic microprocessor, although this thing does have division and multiplication instructions.

The first three ‘frames’ of this computer, containing the general purpose registers, the state and status registers, and the ALU, are already complete. Those circuits are mounted on towering frames made of aluminum extrusion. [James] already has 32 bytes of memory wired up, with each individual bit having its own LED. This RAM display will be used for the Game of Life simulation once everything is working.

While this build may seem utterly impractical, it’s not too different from a few notable and historical computers. The fastest computer in the world from 1964 to ’69 was built from individual transistors, and had even wider busses and more registers. The CDC6600 was capable of running at around 10MHz, many times faster than the estimated maximum speed of [James]’ computer – 25kHz. Still, building a computer on this scale is an amazing accomplishment, and something we can’t wait to see running the Game of Life.

Thanks [aleksclark], [Michael], and [wulfman] for sending this in.

Hackaday Prize Entry: A Medical Tricorder

We have padds, fusion power plants are less than 50 years away, and we’re working on impulse drives. We’re all working very hard to make the Star Trek galaxy a reality, but there’s one thing missing: medical tricorders. [M. Bindhammer] is working on such a device for his entry for the Hackaday Prize, and he’s doing this in a way that isn’t just a bunch of pulse oximeters and gas sensors. He’s putting intelligence in his medical tricorder to diagnose patients.

In addition to syringes, sensors, and electronics, a lot of [M. Bindhammer]’s work revolves around diagnosing illness according to symptoms. Despite how cool sensors and electronics are, the diagnostic capabilities of the Medical Tricorder is really the most interesting application of technology here. Back in the 60s and 70s, a lot of artificial intelligence work went into expert systems, and the medical applications of this very rudimentary form of AI. There’s a reason ER docs don’t use expert systems to diagnose illness; the computers were too good at it and MDs have egos. Dozens of studies have shown a well-designed expert system is more accurate at making a diagnosis than a doctor.

While the bulk of the diagnostic capabilities rely on math, stats, and other extraordinarily non-visual stuff, he’s also doing a lot of work on hardware. There’s a spectrophotometer and an impeccably well designed micro reaction chamber. This is hardcore stuff, and we can’t wait to see the finished product.

As an aside, see how [M. Bindhammer]’s project has a lot of neat LaTeX equations? You’re welcome.


The 2015 Hackaday Prize is sponsored by:

A Thermometer Probe For A Hotplate, Plugging Stuff Into Random Holes

[NurdRage], YouTube’s most famous chemist with a pitch-shifted voice, is back with one of our favorite pastimes: buying cheap equipment and tools, reading poorly translated manuals, and figuring out how to do something with no instructions at all.

[NurdRage] recently picked up a magnetic stirrer and hotplate. It’s been working great so far, but it lacks a thermometer probe. [NurdRage] thought he was getting one with the hotplate when he ordered it, he just never received one. Contacting the seller didn’t elicit a response, and reading the terribly translated manual didn’t even reveal who the manufacturer was. Figuring this was a knock-off, a bit more research revealed this hotplate was a copy of a SCILOGEX hotplate. The SCILOGEX temperature probe would cost $161 USD. That’s not cool.

The temperature probe was listed in the manual as a PT1000 sensor; a platinum-based RTD with a resistance of 1000Ω at 0°C. If this assumption was correct, the pinout for the temperature probe connector can be determined by sticking a 1kΩ resistor in the connector. When the hotplate reads 0ºC, that’s the wires the temperature probe connects to.

With the proper pin connectors found, [NurdRage] picked up a PT1000 on eBay for a few dollars, grabbed a DIN-5 connector from a 20 year old keyboard, and connected everything together. The sensor was encased in a pipette, and the bundle of wires snaked down piece of vinyl tube.

For $20 in parts, [NurdRage] managed to avoid paying $161 for the real thing. It works just as good as the stock, commercial unit, and it makes for a great video. Check that out below.

Thanks [CyberDjay] for the tip.

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