The Tiniest Of 555 Pianos

December 13, 2017 by Jenny List 23 Comments

The 555 timer is one of that special club of integrated circuits that has achieved silicon immortality. Despite its advanced age and having had its functionality replicated and superceded in almost every way, it remains in production and is still extremely popular because it’s simply so useful. If you are of A Certain Age a 555 might well have been the first integrated circuit you touched, and in turn there is a very good chance that your project with it would have been a simple electric organ.

If you’d like to relive that project, perhaps [Alexander Ryzhkov] has the answer with his 555 piano. It’s an entry in our coin cell challenge, and thus uses a CMOS low voltage 555 rather than the power-hungry original, but it’s every bit the classic 555 oscillator with a switchable resistor ladder you know and love.

Physically the piano is a tiny PCB with surface-mount components and physical buttons rather than the stylus organs of yore, but as you can see in the video below the break it remains playable. We said it was tiny, but some might also use tinny.

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How Mini Can A Mini Lamp Be?

December 12, 2017 by Jenny List 4 Comments

If there is one constant in the world of making things at the bench, it is that there is never enough light. With halogen lamps, LEDs, fluorescent tubes, and more, there will still be moments when the odd tiny part slips from view in the gloom.

It’s fair to say that [OddDavis]’ articulated mini lamp will not provide all the solutions to your inadequate lighting woes, as its lighting element is a rather humble example of a white LED and not the retina-searing chip you might expect. The lamp is, after all, an entry in our coin cell challenge, so it hardly has a huge power source to depend upon.

What makes this lamp build neat is its 3D-printed articulated chassis. It won’t replace your treasured Anglepoise just yet, but it might make an acceptable alternative to that cheap IKEA desk lamp. With the coin cell LED you’d be hard pressed to use it for much more than reading even with its aluminium foil reflector, but given a more substantial lighting element it could also become a handy work light.

If 3D printed articulated lamps are your thing, take a look at this rather more sophisticated example.

Pogo Pins Make Light Work Of IoT Switches

December 9, 2017 by Jenny List 7 Comments

Living in a condo with inadequate opportunity for fresh light wiring presented a problem for [Raphael Luckom], which he solved by taking a few off-the-shelf ESP8266-based IoT mains switches. That in itself is nothing particularly new these days, but what makes his switches special is that when faced with fiddly soldering to reprogram them, instead he fabricated a pogo pin jig to make the required contacts.

He took inspiration for his work from a Hackaday.io project hacking some Chinese switched outlets. They contain a standard ESP-12 module, so identifying the correct pins to program them was easy enough. He simply had to create a jig for his pogo pins, which he did with his 3D printer. Of course, “simply” is not an appropriate word, because along the way he had to pass through many iterations of the print, but eventually he had his jig secured to the boards with a clamp.

The result: a successful relay, and without the tricky soldering. We know many of our readers will have no problems with a bit of solder, but for those of you that don’t there might be a bit of interest here.

We’ve shown you many ESP8266 switches over the years. This all-in-one socket system was rather clever, but we’ve had some simple switches too.

Ask Hackaday: Prove Santa Exists

December 9, 2017 by Jenny List 63 Comments

There is no question, that Santa Claus exists. He’s real, with the sleigh, the beard, and the reindeer and everything. He distributes gifts to billions of children in an evening, squeezes down a billion chimneys without getting that stylish red outfit dirty, and gets back home to the North Pole before sunrise. What more proof do you need, after all the missile defence folks track his progress over the icy wastes every Christmas Eve!

Well, the previous paragraph is the story you’ll get from the average youngster in countries where St. Nick is a cultural fixture, and who are we to disabuse them of this notion. Certainly not [Dave Barrett], who has the task of coming up with some ideas for a Santa Proof Of Existence for a kids’ Christmas party. In a previous year he’s thrilled them with a view of the sleigh taking off (in reality a remote-controlled model rocket launch complete with fake air traffic control clearance for Santa via CB radio), but this year the party isn’t somewhere with the space to do that trick. Instead he has the task of maintaining the illusion in those young minds for another year, with only a modest suburban plot in which to do it.

How would you prove Santa’s existence for the credulous young party-goers, using the finest technological marvels available to the Hackaday community? Perhaps you might create the illusion of boots crunching in the snow outside, or maybe the not-so-distant sound of reindeer. We suggest a Santa-Pede won’t cut it, and neither will hiring the beardy member of your hackspace as a stand-in. Kids aren’t that stupid!

What do you think? Go nuts in the comments.

Santa image: Jonathan Lindberg [Public domain].

Feed Your Cat The Modern Way

December 9, 2017 by Jenny List 17 Comments

Feeding the cat should be a moment of magic, in which you bond with your adorable pet as she rubs seductively against your ankles. As you place the saucer of tender and moist meaty chunks on the floor, she bounds the length of your kitchen, excited expression on her little kitty face, and tail in the air.

If Hackaday made television adverts for cat food, we’d have it nailed. But our everyday reality involves the cute-as-heck Hackaday moggy turning into a persistent little pest when she decides it’s feeding time. [ThinkSilicon]’s friends had exactly this problem, with their furry friend’s preferred timing coming early in the morning. His solution? An automated cat feeder (translated) that dispenses kibbles from a hopper into the lucky mouser’s feeding dish.

The mechanical part of this endeavour is pretty straightforward, a servo moves a sliding piece of plywood with a hole cut in it across the bottom of a hopper full of cat food. Move the slide, dispense food down a chute to the waiting happy cat. Behind the scenes is an ESP8266 and a NodeMCU web service, through which feeding time can be either scheduled, or dispensed at will.

A happy cat means a happy owner, especially in the very early morning. Until that is the newly-sated creature decides to spread the love, jumping onto the owner’s bed in thanks and breathing cat-food-breath into their face. You really do have to love ’em!

We’ve shown you many cat food related projects in the past, including this Arduino take on the same idea. But why take the effort to trigger it yourself, when the cat can do it for you.

Never Let Your Christmas Tree Run Dry, With Added Ultrasound

December 9, 2017 by Jenny List 10 Comments

Winter in the parts of the Northern Hemisphere for which observing Christmas includes bringing half a forest into the house should really be divided into two seasons. No-spruce-needles-in-the-carpet season, and spruce-needles-doggedly-clinging-to-the-carpet season. Evergreen trees were not designed for indoor use, and for a hapless householder to stand any chance of keeping those needles on the branches there has to be a significant amount of attention paid to the level of the water keeping the tree hydrated.

[Evan] has paid that attention to the problem of Christmas tree hydration, and to address the shortcomings of earlier designs has come up with a low water warning using an ultrasonic rangefinder. Where previous sensor attempts based on conductive probes succumbed to corrosion or dirt build-up, this one has no contact between sensor and water.

Behind the rangefinder is a CHIP board, whose software sends a text message to his phone when the water level gets a bit low. All the software is available in the linked GitHub page, so should you wish to make your tree safe from thirst, you too can give it a try.

SMS texts are a good way to alert a tree owner, but we quite like the sensor that used the tree lights instead.

Alan Yates: Introduction To Vacuum Technology

December 7, 2017 by Jenny List 17 Comments

When we mention vacuum technology, it’s not impossible that many of you will instantly turn your minds to vacuum tubes, and think about triodes, or pentodes. But while there is a lot to interest the curious in the electronics of yesteryear, they are not the only facet of vacuum technology that should capture your attention.

When [Alan Yates] gave his talk at the 2017 Hackaday Superconference entitled “Introduction To Vacuum Technology”, he was speaking in a much more literal sense. Instead of a technology that happens to use a vacuum, his subject was the technologies surrounding working with vacuums; examining the equipment and terminology surrounding them while remaining within the bounds of what is possible for the experimenter. You can watch it yourself below the break, or read on for our precis.

In the first instance, he introduces us to the concept of a vacuum, starting with the work of [Evangelista Torricelli] on mercury barometers in the 17th century Italy, and continuing to explain how pressure, and thus vacuum, is quantified. Along the way, he informs us that a Pascal can be explained in layman’s terms as roughly the pressure exerted by an American dollar bill on the hand of someone holding it, and introduces us to a few legacy units of vacuum measurement.

In classifying the different types of vacuum he starts with weak vacuum sources such as a domestic vacuum cleaner and goes on to say that the vacuum he’s dealing with is classified as medium, between 3kPa and 100mPa. Higher vacuum is beyond the capabilities of the equipment available outside high-end laboratories.

Introduction over, he starts on the subject of equipment with a quick word about safety, before giving an overview of the components a typical small-scale vacuum experimenter’s set-up. We see the different types of vacuum gauges, we’re introduced to two different types of service pumps for air conditioning engineers, and we learn about vacuum manifolds. Tips such as smelling the oil in a vacuum pump to assess its quality are mentioned, and how to make a simple mist trap for a cheaper pump. There is a fascinating description of the more exotic pumps for higher vacuums, even though these will be out of reach of the experimenter it is still of great interest to have some exposure to them. He takes us through vacuum chambers, with a warning against cheap bell jars not intended for vacuum use, but suggests that some preserving jars can make an adequate chamber.

We are then introduced to home-made gas discharge tubes, showing us a home-made one that lights up simply by proximity to a high voltage source. Something as simple as one of the cheap Tesla coil kits to be found online can be enough to excite these tubes, giving a simple project for the vacuum experimenter that delivers quick results.

Finally, we’re taken through some of the tools and sundries of the vacuum experimenter, the different types of gas torches for glass work, and consumables such as vacuum grease. Some of them aren’t cheap, but notwithstanding those, he shows us that vacuum experiments can be made within a reasonable budget.

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