Dollar Store PCB Holder System

July 6, 2018 by Tom Nardi 3 Comments

As you get into electronic fabrication and repair, one of the first things you realize is how hard it can be to hold a PCB still while you work on it. Securing them is difficult due to their very nature: they’re often weird shapes, quite fragile, and of course need to be electrically isolated. If you don’t mind spending the money, and have the time to wait on it getting delivered, you can order some nice purpose-built systems for holding PCBs online. But what if you need something fast and cheap?

[Paul Bryson] might have the solution for you. On his blog he’s documented how a trip to the dollar store and some parts from the junk bin allowed him to create a practical system for holding multiple PCBs of various shapes and sizes. The most exotic element of the build here are the hexagonal standoffs; and if you haven’t already salvaged a bunch of those from a curbside computer, he even gives the Mouser link where you can buy them new for a few cents each.

Each individual stanchion of the system is made up of a 3/4″ round magnet with a hex standoff glued to the top. Over the standoff, [Paul] slipped a rubber grommet which gives a nice non-conductive slot to put the edge of the PCB in. Otherwise, a second hex standoff screwed into the first can be used to clamp down on the board. Adjusting the height is as simple as adding a couple more magnets to the stack.

Of course, magnets need something metal to stick on. For that, [Paul] purchased some steel pie pans and matching rack from the dollar store. The round pans are easy to handle and give him plenty of surface area, and the rack makes for an exceptionally convenient storage unit for all the components. The conductivity of the pans might be a concern, but nothing the application of a rubberized spray coating couldn’t fix.

We’ve covered similar systems before, but this one certainly looks to take the top spot in terms of economics. The only thing that would be cheaper would be a few feet of PLA filament and a rubber band.

A 38-Year-Old Vocoder Project

July 6, 2018 by Al Williams 12 Comments

It is hard to remember that scant decades ago, electronic magazines — the pre-Internet equivalent of blogs — featured lots of audio circuits based on analog processing. Music synthesizers were popular for example, because microcontrollers were expensive and unable to perform digital signal processing tasks in the way you would use them today. [Julian] has been trying to build a vocoder from that era from ETI magazine. Along the way, he’s making videos documenting what he’s found and how’s he resolving issues.

The circuit generates levels for particular input frequencies. It does so with a two-op-amp bandpass filter, a two-op-amp rectifier, and then an op-amp lowpass filter. That’s five op-amps for each band (there are 14 bands) plus the support circuitry. And that’s just the input section! Today, you would simply sample the signal and do a fast Fourier transform (FFT) to get the same kind of data.

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DIY Socket For Prosthetics Contains Power Supply, Charger

July 6, 2018 by Donald Papp 5 Comments

Innovation in prosthetics is open to anyone looking to enhance the quality of life, but there’s an aspect of it that is sometimes under-served. The DIY Prosthetic Socket entry to the Hackaday Prize is all about the foundation of a useful prosthesis: a custom, form-fitting, and effective socket with a useful interface for attaching other hardware. While [atharvshringaregt] is also involved with a project for a high-tech robotic hand with meaningful feedback, socket fitting and design is important enough to be its own project.

The goal is not just to explore creating these essential parts in a way that’s accessible and affordable to all, but to have them include a self-contained rechargeable power supply that can power attachments. Thoughtful strap placement and a power supply design that uses readily available components with a 3D printed battery housing makes this DIY prosthetic socket a useful piece of design that keeps in mind the importance of comfort and fitting when it comes to prosthetics; even the fanciest robot hand isn’t much good otherwise.

A Sneak Preview Of The Hacker Warehouse Badge

July 6, 2018 by Brian Benchoff 5 Comments

We were lucky enough to get our hands on a hand-soldered prototype of the new Hacker Warehouse badge, and boy is this one a treat. It’s fashionable, it’s blinky, and most impressively, it’s a very useful tool. This badge can replace the Google Authenticator two factor authentication app on your phone, and it’s a USB Rubber Ducky. It’s also a badge. Is this the year badges become useful? Check out the video below to find out more.

This is the time of year when hardware hackers from all across North America are busy working on the demoscene of hardware and manufacturing. This is badgelife, the celebration of manufacturing custom wearable electronics for one special weekend in Las Vegas. In just about a month from now, there will be thousands of independent badges flooding Caesar’s Palace in Vegas, complete with blinkies, custom chips, innovative manufacturing processes, and so many memes rendered in fiberglass and soldermask.

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Electronic ColorChord Turns Color Into Sound

July 6, 2018 by Steven Dufresne 13 Comments

[Dr. Cockroach] has delighted us again with another of his circuits on cardboard. He calls it steampunk inspired, and while we guess we can see what he’s getting at, it’s more like a sweet example of artful dead bug construction. He calls it the ColorChord. Point its photo cells at a color and it’ll play a tone or a combination of tones specific to that color.

Three 555-centric boards use thumbtacks as connection points which he solders to, the same technique he used for his cardboard computer. They provide simple tones for red, green, and blue and a mix for any other color. However, he found that the tones weren’t distinguishable enough for similar colors like a bright sun yellow and a reddish yellow. So he ended up pulsing them using master oscillator, master-slave flip-flop, and sequencer circuits, all done dead bug style.

We’re not sure how practical it is but the various pulsed tones remind us of the B space movies of the 1950s and 60s. And as for the look of it, well it’s just plain fun to look at. Hear and see it for yourself in the video below.

And if you want to see some dead bug circuitry as high art then check out this awesome LED ring, this sculptural nixie clock, and perhaps the most wondrous of all, The Clock.

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Circuit VR: Simple Buck Converters

July 6, 2018 by Al Williams 19 Comments

The first thing I ever built without a kit was a 5 V regulated power supply using the old LM309K. That’s a classic linear regulator like a 7805. While they are simple, they waste a lot of energy as heat, especially if the input voltage goes higher. While there are still applications where linear regulators make sense, they are increasingly being replaced by switching power supplies that are much more efficient. How do switchers work? Well, you buy a switching power supply IC, add an inductor and you are done. Class dismissed. Oh wait… while that might be the best way to do it from a cost perspective, you don’t really learn a lot that way.

In this installment of Circuit VR, we’ll look at a simple buck converter — that is a switching regulator that takes a higher voltage and produces a lower voltage. The first one won’t actually regulate, mind you, but we’ll add that in a future installment. As usual for Circuit VR, we’ll be simulating the designs using LT Spice.

Interestingly, LT Spice is made to design power supplies so it has a lot of Linear Technology parts in its library just for that purpose. However, we aren’t going to use anything more sophisticated than an op amp. For the first pass, we won’t even be using those.

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An Optical Mouse Sensor For Robotic Vision

July 6, 2018 by Jenny List 22 Comments

Readers with long memories will remember the days when mice and other similar pointing devices relied upon a hard rubber ball in contact with your desk or other surface, that transmitted any motion to a pair of toothed-wheel rotation sensors. Since the later half of the 1990s though, your rodent has been ever significantly more likely to rely upon an optical sensor taking the form of a small CCD camera connected to motion sensing electronics. These cameras are intriguing components with applications outside pointing devices, as is shown by [FoxIS] who has used one for robot vision.

The robot in question is a skid-steer 4-wheeled toy, to which he has added an ADNS3080 mouse sensor fitted with a lens, an H-bridge motor driver board, and a Wemos D1 Mini single board computer. The D1 serves a web page showing both the image from the ADNS3080 and an interface that allows the robot to be directed over a network connection. A pair of LiPo batteries complete the picture, with voltage monitoring via one of the Wemos analogue pins.

The ADNS3080 is an interesting component and we’d love see more of it. This laser distance sensor or perhaps this car movement tracker should give you some more info. We’ve heard rumors of them being useful for drones. Anyone?