Cyclist’s LED Pixel Clock Has No Fat Around The Middle

If you like LED clocks and illuminated bicycle wheels, [Harald Coeleveld] has just the right weekend project for you. His RGB pixel LED clock is as simple as it is beautiful, and it can be built in no time: The minimalist and sporty design consist of not much more than a LED strip wrapped around a bicycle wheel rim.

[Harald] took 2 meters of addressable WS2812 LED strip (with 30 LEDs per meter, we assume), wrapped it around a 27″ bicycle rim padded with a foam strip, and obtained 60 equally spaced RGB LEDs on a ring, ideal for displaying time. Apparently, the rim-tape circumference of this particular 27″ bicycle wheel is close enough to 2 meters, so it lines up perfectly.

On the electronics side, the project employs an Arduino Nano and a DS3231 precision RTC module. For switching between two illumination modes for day and night, [Harald] also added a photoresistor. During the day, colored dots around the ring display the time: A red dot for the seconds, a blue one for the minutes, and a group of 3 green LEDs for the hours. At night, the entire ring shimmers with an effective red glow for easier readability.

The Arduino code for this build can be downloaded from the project page, enabling anyone to effortlessly replicate this design-hack in under an hour!

Design for Hackers

Near the end of the lifecycle of mass-market commercial product development, an engineering team may come in and make a design for manufacturability (DFM) pass. The goal is to make the device easy, cheap, and reliable to build and actually improve reliability at the same time. We hackers don’t usually take this last step, because when you’re producing just a couple of any given device, it hardly makes sense. But when you release an open-source hardware design to the world, if a lot of people re-build your widget, it might be worth it to consider DFM, or at least a hardware hacker’s version of DFM.

If you want people to make their own versions of your project, make it easy and cheap for them to do so and don’t forget to also make it hackable. This isn’t the same as industrial DFM: rather than designing for 100,000s of boards to be put together by robot assembly machines, you are designing for an audience of penny-pinching hackers, each building your project only once. But thinking about how buildable your design is will still be worthwhile.

In this article, I’m going to touch on a couple of Design for Hackers (DFH) best practices. I really want to hear your experience and desires in the comments. What would you like to see in someone else’s open designs? What drives you nuts when replicating a project? What tricks do you know to make a project easily and cheaply buildable by the average hacker?

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Oscillating Pneumatic Mechanism Doesn’t Need a Purpose

It’s true that a lot of the projects we feature here (and build ourselves) are created to accomplish some sort of goal. But, many times the project itself is the goal. That’s the case with [Proto_G’s] self-oscillating pneumatic machine, which he built with no particular use in mind.

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Robo Hobo Bamboozles Passers-By

Robots are increasingly seeing the world outside of laboratories and factories, and most of us think we would be able to spot one relatively quickly. What if you walked past one on the street — would you recognize it for what it was? How long would it take for you to realize that homeless organ grinder was a robot?

The brainchild of [Fred Ables], Dirk the homeless robot will meander through a crowd, nodding at passers-by and occasionally — with a tilt of his hand — ask for change, churning out a few notes on his organ for those who oblige him. [Ables] controls Dirk’s interactions with others remotely from nearby, blending into the crowds that flock to see the lifelike automaton, selling the illusion that Dirk is a real human. This is often effective since — as with most homeless people — pedestrians won’t spare Dirk a second glance; the reactions of those who don’t pass him over range from confusion to anger or mirth over being so completely duped before looking for the puppeteer.

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Hackaday Prize Entry: A Cheap Robotic Microscope

The microscope is one of the most useful instruments for the biological sciences, but they are expensive. Lucky for us, a factory in China can turn out webcams and plastic lenses and sell them for pennies. That’s the idea behind Flypi – a cheap microscope for scientific experiments and diagnostics that’s based on the ever-popular Raspberry Pi.

Flypi is designed to be a simple scientific tool and educational device. With that comes the challenges of being very cheap and very capable. It’s based around a Raspberry Pi and the Pi camera, with the relevant software for taking snapshots, recording movies, and controlling a few different modules that extend the capabilities of this machine. These modules include a Peltier element to heat or cool the sample, a temperature sensor, RGB LED, LED ring, LED matrix, and a special blue LED for activating fluorescent molecules in a sample.

The brains behind the Flypi, [Andre Chagas], designed the Flypi to be cheap. He’s certainly managed that with a frame that is mostly 3D printed, and some surprisingly inexpensive electronics. Already the Flypi is doing real science, including tracking bugs wandering around a petri dish and fluorescence microscopy of a zebrafish’s heart. Not bad for a relatively simple tool, and a great entry for the Hackaday Prize.

Mergers and Acquisitions: Analog and Linear

Analog Devices and Linear Technology have announced today they will combine forces to create a semiconductor company worth $30 Billion.

This news follows the very recent acquisition of ARM Holdings by Japan’s SoftBank, and the later mergers, purchases or acquisitions of On and Fairchild, Avago and Broadcom, NXP and Freescale, and Microchip and AtmelIntel and Altera, and a few more we’re forgetting at the moment.

Both Analog and Linear address similar markets; Analog Devices is best known for amps, interface, and power management ICs. Linear, likewise, isn’t known for ‘fun’ devices, but without their products the ‘fun’ components wouldn’t work. Because the product lines are so complimentary, the resulting company will stand to save $150 Million annually after the deal closes.

Analog and Linear are only the latest in a long line of semiconductor mergers and acquisitions, but it will certainly not be the last. The entire industry is consolidating, and the only way to grow is by teaming up with other companies. This leads the question if there will eventually only be one gigantic semiconductor company in the future. You’ll get different answers to that question from different people. Hughes, Fairchild, Convair, Douglas, McDonnell Douglas, North American, Grumman, Northrop, Northrop Grumman, Bell, Cessna, Schweizer and Sikorsky would say yes. Lockheed Martin and Boeing would say no. It’s the same thing.

Pressure-formed Parabolic Mirror from a Mylar Blanket

Parabolic reflectors are pretty handy devices. Whether you’re building a microwave antenna or a long-distance directional microphone, suitable commercial dishes aren’t that hard to come by. But a big, shiny mirror for your solar death-ray needs is another matter, which is where this pressure-formed space blanket mirror might come in handy.

Pressure-forming was a great choice for [NighthawkInLight]’s mirror. We’ve covered pressure-formed plastic domes before, and this process is similar. A sheet of PVC with a recessed air fitting forms the platen. The metallized Mylar space blanket, stretched across a wooden frame to pull out the wrinkles and folds, is applied to a circle of epoxy on the platen. After curing, a few puffs with a bicycle tire pump forms the curve and stretches the film even smoother. [NighthawkInLight]’s first attempt at supporting the film with spray foam insulation was a bust, but the later attempt with fiberglass mesh worked great. A little edge support for the resulting shiny taco shell and the mirror was capable of the required degree of destructive potential.

We doubt this process can be optimized enough to produce astronomy-grade mirrors for visible light, but it still has a lot of potential applications. Maybe a fiberglass radio astronomy dish could be pressure-formed directly with a rig like this?