The Tiny Radio Telescope

July 31, 2016 by 40 Comments

Radio telescopes are one of the more high-profile pieces of scientific apparatus. There is an excitement to stories of radio astronomers of old probing the mysteries of the Universe on winter nights in frigid cabins atop massive parabolas, even if nowadays their somewhat more fortunate successors do the same work from the comfort of their labs using telescopes that may be on the other side of the world.

You might think if you look at the Arecibo Observatory, Lovell Telescope, or other famous pieces of apparatus, that this is Big Science, out of reach for mere mortals such as yourself without billion-dollar research programs. Maybe [Paul Scott] and [Allen Versfeld]’s Tiny Radio Telescope project will change that view.

The NRAO published a radio telescope design a few years ago for use mainly as an educational tool, the Itty Bitty Telescope. It used a satellite TV dish and LNB feeding a signal meter as a simple telescope to detect the Sun, and black body radiation from the surrounding objects. It’s a simple design for kids to get their heads around, and [Scott] and [Allen] have set out to turn it into something more useful with an RTL-SDR instead of a signal meter and a motorised mount for automated observations.

This is one of those projects on Hackaday.io that moves slowly but you know will eventually deliver on its promise. With a 1m dish and a consumer LNB it’s never going to make a discovery that will rock the world, but that’s not the point. It may be science that the astrophysicists moved on from decades ago, but it’s still quite an achievement that the radio sky can be imaged using such mundane equipment.

We’ve featured backyard radio astronomy before a few times, from this UHF school science project to another satellite TV based telescope. Keep them coming!

A thank you to Southgate ARC for the prod.

Taking The Converted PC PSU Bench Supply A Step Further

July 31, 2016 by 51 Comments

A quality bench power supply is essential for electronics work. Nobody wants to go through the trouble of digging through their electronics bin just to find a wall wart with the right output. And, even if you were so inclined, it would be folly to assume that its output would actually be clean.

You could, of course, purchase a purpose-built bench power supply. But, this is Hackaday, and I’m sure many of you would rather build one yourself from an inexpensive PC power supply. Normally, you’d do this by separating out the different voltage lines into useful groups, such as 12V, 5V, and 3.3V. [Supercap2f] wanted to take this a step further, both to get a more useful unit and to practice his PCB-making.

His design uses a custom circuit design to fuse the circuits, and to provide some basic logic. Using the LCD display, you can see which lines are powered on. There is even a simple 3D printed cover to keep everything neat and tidy. [Supercap2f] has posted all of the design files, so you can build one of these yourself. We’ve seen similar builds in the past, but this is another nice one that anyone with the ability to etch PCBs can build.

Vending Coins For Your Vending Machine

July 31, 2016 by 36 Comments

Anyone who has worked in an office with a vending machine knows this problem well: someone wants a snack or a drink from the vending machine, but doesn’t have any small change. So, they proceed to walk around the office trying to find someone to make some change for them. It’s a hassle, and a surprisingly common one. Sure, a lot of vending machines now accept credit cards, but they’re still in the minority.

This was the problem facing Belgium-based automation company November Five. As automation and IoT specialists, their first thought was to hack the vending machine itself. But, unfortunately, they didn’t own it; as many of you know, vending machines are generally owned by the distributor. So, they needed a solution that allowed their employees access to the vending machine, without actually modifying the vending machine itself.

The solution they came up with was to attach an RFID-activated coin dispenser to the vending machine. Everyone at the company already has an RFID badge for opening doors and such, so the system wouldn’t add any burden to the employees. And keeping track of how many coins each employee used was a simple task of logging requests.

Continue reading “Vending Coins For Your Vending Machine” →

Parent To The Power Wheels Rescue

July 31, 2016 by 13 Comments

If the [realjohnnybravo] is the one from the show, it appears he finally managed to get a girlfriend, marry her, and produce at least one son. As the old schoolyard rhyme goes, first comes love, then comes marriage, then comes filling the whole *!$&# backyard with brightly colored plastic garbage. One of these items, a Power Wheels quad bike,  suffered a blow from planned obsolescence leaving behind a traumatized child. [realjohnnybravo] decided to fix it.

He made frequent mention of how one could go to a store and purchase replacement gears for the toy. Perhaps it’s a German thing. Regardless, he shows experience with internet comments by justifying his adventure in gear manufacturing with, paraphrased, “I’m having fun and learning so back off you pedantic jerks.”

Resin casting is great, and is often overlooked vs 3D printing. He purchased some hardware store RTV silicone and some slow-cure resin. The faster cure resin would get too hot with this much volume and potentially burn.

Materials procured he took apart both gearboxes from the machine. He first made a silicone mold of the broken parts (from the good copies out of the working gearbox) and removed the master. Without a vacuum or pressure casting chamber, the molds came out a little rough and bubbly, but it’s nothing some work with a carpet knife can’t fix. For big gears like this it hardly matters. Next he poured the two part resin into the molds and waited.

After some finishing with regular woodworking tools the parts fit right into the voids in the defective gearbox. His son can once again happily whir around the lawn, until the batteries die anyway.

Hackaday Prize Entry: You Have No Free Will

July 30, 2016 by 79 Comments

The concept of free will is the perfect example of human arrogance ever conceived. If a gas molecule collides with another gas molecule, simple physics can determine the momentum of the first gas molecule, the kinetic energy imparted to the second gas molecule, and the resulting trajectories of both molecule. Chemical reactions are likewise easy to calculate. Scale a system up to something the size of a human brain, and you have a perfectly predictable system. It’s complex, yes, but predetermined since the beginning of time. You are without moral agency, or any independent thought of your own. You are merely a passive observer in a vast, cold, uncaring universe. You are cursed with the awareness of this fact.

For his Hackaday Prize project, [Patrick Glover] is proving we don’t have free will. Will he win the Hackaday Prize? That’s up for the cold machinations of fate to decide.

In the 1980s, psychologist [Benjamin Libet] performed an experiment. He connected an EEG to a subject’s arm and head, and asked them to flex their wrist whenever they felt like it. It turns out, an area of your brain generates an EEG potential a significant time before the subject is aware of deciding to flex their wrist. This is a foundational study in the physiology of consciousness, and direct evidence an IRB is okay with giving subjects an existential crisis.

[Patrick] is in the process of replicating the [Libet] study. Unlike the 1980s experiment, [Patrick] has access to handy Arduino shields and MATLAB, making the experimental setup very easy. The results, of course, will be the subject of philosophical debates continuing until the heat death of the universe, but we already knew that, didn’t we?

Check out the comments below for objectors predictably saying they do, in fact, have free will.

The HackadayPrize2016 is Sponsored by:

NFL To Experiment With Chipped Balls

July 30, 2016 by 29 Comments

NFL preseason starts in just a few weeks. This year, it will come with a bit of a technological upgrade. The league plans to experiment with custom microchip-equipped footballs. Unfortunately, this move has nothing to do with policing under-inflation — the idea is to verify through hard data that a narrower set of goal posts would mean fewer successful kicking plays.

Why? Kicking plays across the league have been more accurate than ever in the last couple of seasons, and the NFL would like things to be a bit more competitive. Just last year, extra point kicks were moved back from the 20 to the 33-yard line. Kickers already use brand-new balls that are harder and more slippery than the field balls, so narrowing the goal from the standard 18’6″ width is the natural next step. A corresponding pair of sensors in the uprights will reveal exactly how close the ball is when it passes between them.

The chips will only be in K-balls, and only in those kicked during the 2016 preseason. If all goes well, the league may continue their use in Thursday night games this season. We couldn’t find any detail on these custom-made chips, but assume that it’s some kind of transmitter/receiver pair. Let the speculation begin.

Main image: Field goal attempt during the Fog Bowl via Sports Illustrated

[via Gizmodo]

Arduino Absentmindedly Blows Bubbles

July 30, 2016 by 12 Comments

If you ever wanted to make an occasion festive with bubbles, [Sandeep_UNO] may have the project for you. As you can see in the video below (and, yes, it should have the phone rotated and it doesn’t), his Arduino uses a servo motor to dip a bubble wand into soap solution and then pulls it in front of a fan. The entire operation repeats over and over again.

There’s not a lot of detail and no code that we could find, but honestly, if you know how to drive a servo motor from an Arduino, the rest is pretty easy to figure out. Look closely at the motion of the robot. What is often accomplished with a spinning wheel of bubble wands and a constant fan becomes much more interesting when applied intermittently. The lazy cadence is what you expect to see from human operation and that adds something to the effect.

We’ve seen faster bubble blowers, but they were not so simple. We’ve even looked at other bubble-blowing robots. If you want to find out more about servo motors in general, our own [Richard Bauguley] has what you need to know.

Continue reading “Arduino Absentmindedly Blows Bubbles” →