Generating Power With Wind, Water, And Solar

December 9, 2018 by Al Williams 22 Comments

It is three weeks after the apocalypse. No zombies yet. But you do need to charge your cell phone. How do you quickly make a wind turbine? If you’ve read this project, you might reach for a few empty water bottles. This educational project might not charge your phone without some extra work, but it does illustrate how to use water bottles to make a workable air scoop for turning a crank and possibly generating electricity.

That takes care of the wind and water aspects, but how did we get solar? According to the post — and we agree it is technically true — wind power is a form of solar power since the wind is driven by temperature differences created by the sun. Technically true!

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FPGA Used VHDL For Fractals

December 9, 2018 by Al Williams 9 Comments

Over on GitHub, [ttsiodras] wanted to learn VHDL. So he started with an algorithm to do Mandelbrot sets and moved it to an FPGA. Because of the speed, he was able to accomplish real-time zooming. You can see a video of the results, below.

The FPGA board is a ZestSC1 that has a relatively old Xilinx Spartan 3 chip onboard. Still, it is plenty powerful enough for a task like this.

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Easily Deboss Notebooks With A 3D Printed Stamp

December 9, 2018 by Tom Nardi 14 Comments

While it’s arguably a bit closer to the “Arts & Crafts” region of the making spectrum upon which we don’t usually tread on account our l33t sense of superiority, we’ve got to admit that the quick and easy notebook customization demonstrated by [Sean Hodgins] is very compelling. We don’t put ink to dead trees with nearly the frequency we used to, but when we do it might as well be Hemingway-style with a little black Hackaday emblazoned notebook.

As demonstrated in the video after the break, the process starts by designing the stamp in your CAD package of choice. For optimal results [Sean] suggests fairly large capital letters, but with practice you should be able to get into some more creative fonts. Potentially you could even use the logo of your favorite hacking blog, but who are we to dictate what you do?

Whatever you chose, it needs to be mirrored and placed on a relatively thick backing. He recommends a 2 mm thick “plate” with the letters raised on top. You’ll want to print it at a high infill percentage, but even still it shouldn’t take more than 30 minutes or so to run off. Remember there tends to be diminishing returns on infill past 50%, so taking it all the way to 100% is not going to do much but expend more time and plastic.

Once printed, [Sean] hot glues the stamp to a block of wood since putting pressure on the printed piece directly would likely crack it. Then it’s just a matter of getting your notebook, printed stamp, and blocks of wood lined up in to a suitably beefy bench vise. Getting everything aligned is one of those things that easier said than done, so expect to mess up the first couple until you get the hang of it.

When the alignment looks good, crank it down and let it sit for a few minutes. If you’re embossing the design into actual leather, wetting it a bit before putting the pressure on should help. The final effect is understated but undeniably very slick; and with the Holidays rapidly approaching this might be an excellent way to knock out some legitimately thoughtful gifts.

Ultimately the idea here is something of a lightweight version of the 3D printed press break dies used to bend aluminum or the punch and die set used for steel plates. At this point it seems there’s enough evidence to say that 3D printed objects are certainly strong enough (in compression, at least) to put some legitimate work in.

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Furby Plus Borges Equals Borgy

December 8, 2018 by Richard Baguley 10 Comments

What do you get if you cross a Furby with a master of 20th Century literature? The Borgy. Argentinian hacker [Roni Bandini] found an old Furby and decided to hack it by altering its personality. His inspiration was the Argentinian writer Jorge Louis Borges, one of the pioneers of surrealist writing. The idea is that, at random times during the day, the Borgy will share a bit of wisdom from Borges to inspire and enlighten.

[Roni] hacked the Furby to replace the speaker with a more powerful one, and built a base to hold the larger speaker and a switch which can activate Borgy. He also used an Arduino Nano and a Sparkfun MP3 player shield loaded with the samples of Borges.

When the Furby speaks, it shares some wisdom from Borges. It’s a simple, but a surprisingly effective hack that could be very useful for someone seeking inspiration. Or, as Borges himself once said: “Don’t talk unless you can improve the silence.”

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An Over-engineered LED Sign Board

December 8, 2018 by Inderpreet Singh 10 Comments

Never underestimate the ability of makers in over thinking and over-engineering the simplest of problems and demonstrating human ingenuity. The RGB LED sign made by [Hans and team] over at the [Hackheim hackerspace] in Trondheim is a testament to this fact.

As you would expect, the WS2812 RGB LEDs illuminate the sign. In this particular construction, an individual strip is responsible for each character. Powered by an ESP32 running FreeRTOS, the sign communicates using MQTT and each letter gets a copy of the 6 x 20 framebuffer which represents the color pattern that is expected to be displayed. A task on the ESP32 calculates the color value to be displayed by each LED.

The real question is, how to calibrate the distributed strings of LEDs such that LEDs on adjacent letters of the sign display an extrapolated value? The answer is to use OpenCV to create a map of the LEDs from their two-dimensional layout to a lookup table. The Python script sends a command to illuminate a single LED and the captured image with OpenCV records the position of the signal. This is repeated for all LEDs to generate a map that is used in the ESP32 firmware. How cool is that?

And if you are wondering about the code, it is up on [Github], and we would love to see someone take this up a level. The calibration code, as well as the Remote Client and ESP32 codes, are all there for your hacking pleasure.

Its been a while since we have seen OpenCV in action like with the Motion Tracking Turret and Face Recognition. The possibilities seem endless. Continue reading “An Over-engineered LED Sign Board” →

Advent Calendar – ‘Tis The CNSeason

December 8, 2018 by Lewin Day 3 Comments

CNC machines are powerful tools when used correctly, but it’s often necessary to test a new machine before getting into serious production work. This advent calendar is a great festive project that was designed to put a CNC through its paces.

The calendar is made primarily from wood. This is an excellent choice for test machining projects, as it is softer and less likely to cause tool or machine damage when compared to steel or aluminum. The calendar base was first milled out using end mills, while a 30-degree V-bit was used to engrave the days of the week. Brass brazing rod was then used to create hangers for the calendar tags.

Thanks to the clever use of chalkboard paint and removable tags, the calendar can be reconfigured to work for any given year and month combination — just in case you wish to have an advent calendar year round. Overall, it’s a good low-intensity machining project that would also be a fun craft project for kids.

As it’s that time of year, you might like this blinky advent calendar, too. Video after the break.

[Thanks to Michael for the tip!]

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Crystal Oscillators Explained

December 8, 2018 by Al Williams 13 Comments

We’ve read a lot about oscillators, but crystal oscillators seem to be a bit of a mystery. Hobby-level books tend to say, build a circuit like this and then mess with it until it oscillates. Engineering texts tend to go on about loop gains but aren’t very clear about practice. A [circuit digest] post that continues a series on oscillators has a good, practical treatment of the subject.

Crystals are made to have a natural resonant frequency and will oscillate at that frequency or a multiple thereof with the proper excitation. The trick, of course, is finding the proper excitation.

The post starts with a basic model of a crystal having a series capacitance and inductance along with a resistance. There’s also a shunt or parallel capacitor. When you order a crystal, you specify if you want the resonant frequency in series or parallel mode — that is, which of the capacitors in the model you want to resonate with the inductor — so the model has actual practical application.

By applying the usual formula for resonance on the model you’ll see there is a null and a peak which corresponds to the two resonance points. The dip is the series frequency and the peak is the parallel. You can actually see a trace for a real crystal in a recent post we did on the Analog Discovery 2. It matches the math pretty well, as you can see on the right.