From Hacker Hotel 2020: Badges, Sharks, Tentacles, Old-School Hacking, And Much More

March 6, 2020 by Jenny List 9 Comments

The North Sea in a winter storm is a spectacular sight, one of foam-crested waves and squalls driven on the gale. It’s not a place to spend a lot of time if you are a land-lubber, so to cross it twice in a few weeks must mean there is something very much worth seeing on its other side.

More of that exotic cruise ship lifestyle.

But one of the best antidotes to February weather in the European hacker community was Hacker Hotel 2020. Around 350 people came from all the countries of the northwest of the continent to the comfort and hospitality of the Westcord Hotel de Veluwe in the eastern Netherlands, to experience a hacker camp with all the convenience and luxury of a resort hotel rather than a muddy field.

Three days in this environment results in a camp that’s just a bit special, and one that’s very much worth a visit if your range extends this far.

An Upscale Hotel Gets The Hacker Treatment

The Hacker Hotel badge 2020 has many hidden depths

Our small party of Brits arrived a day early, on a damp Thursday morning ready to lend a hand with the set-up. Slowly an upscale business conference centre was transformed into a hacker camp venue, with conference rooms turned into lecture halls, lighting and video equipment in place and 3-phase power cables snaking along the skirting boards. A large hardware hacking area was set up in one wing of the building, then the EventInfra people came in and laid out a hacker-camp-grade wireless and wired network that delivered connectivity everywhere. The contrast between the two worlds is significant, but together they make for a unique experience.

One by one, hackers arrived from all points of the compass, bearing crates of the usual cool stuff. An amateur TV satellite earth station, a brace of oversized delta 3D printers, a coin-pushing game that’s familiar from other camps. And smaller projects; little roving robots, indoor-sized multirotors, and several crates of outdated Chinese photo-frames that it’s said can be hacked to run a Linux distro.

This is the lifeblood of a hacker camp, but of course the signature piece of hardware for any hacker camp is its badge. In this Hacker Hotel 2020 didn’t disappoint, with a beautifully designed Ancient Egyptian-themed badge that concealed an array of puzzles across multiple levels. We’ll cover the badge in detail in a separate piece, but suffice to say that it is something of a tour de force. For now let’s jump into all of people and activities on offer at the con.

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Blister Pack With Jet Fighter Toy Is A Business Card

March 5, 2020 by Jenny List 20 Comments

In the world of business cards, it seems that for some people a white rectangle of card just doesn’t cut it any more. A card isn’t simply a means to display your contact details, instead it can be a way to show off your work and demonstrate to the world your capabilities. For [agepbiz] those are the skills of a 3D design specialist, so what better way to proceed than by distributing a 3D-printed example of his work? How to render that into a business card? Put it in a retail-style blister pack, of course. Take a look at the video below the break.

It’s an interesting process to follow, because there are certainly readers who will have toyed with the idea of selling their work, and this makes an attractive way to display a small assembly while still keeping it safe from damage. The toy – a small 3D-printed jet fighter with working swing wings that’s a masterpiece in itself – is laid on a backing card and a custom blister is glued over it. The manufacture of the printed backing card with a CNC card cutter is shown, followed by that of the blister with a custom SLA-printed mould being used to vacuum-form a sheet of clear plastic. Surprisingly the whole is assembled with just a glue stick, we’d have expected something with a bit more grab. The result is a professional-looking blister packed product of the type you wouldn’t bat an eyelid over if you saw it in a shop, and one of those things that it’s very useful to have some insight into how one might be made..

It’s possible this card might be a little bulky to slip in your wallet, but it’s hardly the only novelty card we’ve brought you over the years. Some of our most recent favourites run Linux or play Tetris.

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Just When You Thought There Was Nothing New In Nixie Clocks…

March 3, 2020 by Jenny List 9 Comments

Nixie clocks have become such a staple in our community as to have become mundane. They’re pretty, but show us something new! It seems [Marcin Saj] has done just that with his offering, because with a bank of 18 IN-2 Nixie tubes he’s telling the time – but in binary rather than the usual decimal.

The tubes are arranged in three banks of six, the upper registering hours, the middle minutes, and seconds on the lowest. Each one only uses two digits, as you might expect from a binary device they are 0 and 1. Behind is a large PCB with the Nixie sockets, and on the back of that in sockets are a pair of Nixie driver boards, a real-time clock module, temperature sensor module, PSU module, and either a Particle Photon or an Arduino Nano IoT. This two-option set-up for the choice of dev board is unusual, and there is code for both of them in the GitHub repository.

The result is eye-catching and unusual, and certainly a departure from the usual Nixie digital clock. Hackaday readers are probably more likely than the average Joe or Jane to be able to read binary at a glance, watching it in action in the video below the break is an interesting exercise in testing one’s binary-aptitude.

Meanwhile if binary Nixies are too commonplace, how about binary neon lamps?

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Generate Power As You Ride With A Bicycle Planar Alternator

March 2, 2020 by Jenny List 21 Comments

For most riders, bicycle lighting consists of an array of LED lamps and flashing gizmos, usually powered by lithium-ion batteries, or coin cells for the smaller ones. Some people though prefer to dispense with batteries and generate their own power, and that’s what [Thomas D] has done by fitting his bike with an alternator. But this is no off the shelf unit that rubs the tire or sits in a wheel hub. Instead, he’s built his own planar alternator that attaches to the spokes.

The design is inspired by those used in some wind generators, a central disk holding a set of planar coils sits between two rotating disks holding magnets. The stator holding the coils is made from laser-cut acrylic, and the rotors holding the magnets are sheet steel. One rotor is attached to the rear wheel spokes of the bicycle in close proximity to the stator which is attached to the rear frame. The second rotor sits on the other side of the stator while attached to the first rotor by its edge.

The coils are wired as two parallel groups in series in a ring with a single-phase output that feeds a rectifier and DC to DC converter. It would be interesting to see the effect of the same alternator with different winding arrangements or multiple phases.

This is the first time we’ve seen one of these on a bicycle, but this type of alternator has appeared here in more than one wind generator.

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Never Miss A Doorbell With This Notifier

March 1, 2020 by Jenny List 14 Comments

[PatH] tells us that he tragically missed a craft beer delivery to his home, and vowed never to let this happen again. His problem was that he’d missed the doorbell, resulting in one of those annoying notes from the delivery guy. His solution? An ESP8266-driven doorbell detector, that both sends him an SMS and records each doorbell press to a Google Sheet.

The doorbell detection is surprising but simple and non-intrusive, instead of running a GPIO line through some kind of interface to the button itself he’s added a reed switch to his ESP8266 board and used that to detect the magnetic field of the bell solenoids. It’s a convenient method, but one that only works with an old-style bell.

When the bell rings the magnetic field triggers the reed switch, and in turn the sketch running on the ESP calls out to IFTTT which triggers both an SMS and a write to a Google Sheets document that records each doorbell activation.

The ESP8266 seems to be a popular choice with doorbell automatprs probably because of its built-in networking and low price, but it’s not the only option. This optocoupler-sensed effort for example uses a Particle Xenon.

A Patch Antenna Is Just A Rectangle, It Should Be Easy To Design, Right?

March 1, 2020 by Jenny List 20 Comments

If a grizzled RF engineer who bears the soldering-iron scars of a thousand projects could offer any advice, it would be that microwave antennas are not a field to be entered into lightly. Much heartache is to be saved by using an off-the-shelf design, and only the foolhardy venture willingly down the stripline into the underworld of complex microwave resonances.

But every would-be microwave designer has to start somewhere, and for [Adam Gulyas] that start came with a 2.4 GHz patch antenna. His write-up is a fascinating tale of the challenges and pitfalls of creating something which is deceptively simple at first sight but which becomes significantly more complex as he characterizes his design made real as a PCB.

The process started with a set of calculations to derive the patch dimensions and a bit of PCB work adding a stripline feed. This was produced on a PCB, a normal 1.6mm thick FR4 fiberglass board. When hooked up to a VNA its impedance was all wrong. Further, it had a resonance at the required frequency but also unexpected ones at 3.7 and 4.6 GHz. Simulation of the design also yielded a different resonance from the one calculated, and discussing it with others yielded the conclusion that the feed might be at fault. He ended up using an inset feed, with a co-axial cable emerging away from the edge of the patch, and was able to achieve a far better result.

We can all learn something from [Adam]’s write-up, and we salute him for staying the course to get the design to a usable point. It would be interesting to see the same antenna produced from a more consistent dielectric material than generic FR4. Meanwhile, if you are interested in microwave RF design, take a look at Michael Ossmann’s primer on the subject.

Assistive Specs Help Jog Your Memory

March 1, 2020 by Jenny List 3 Comments

It’s something that can happen to all of us, that we forget things. Young and old, we know things are on our to-do list but in the heat of the moment they disappear from our minds and we miss them. There are a myriad of technological answers to this in the form of reminders and calendars, but [Nick Bild] has come up with possibly the most inventive yet. His Newrons project is a pair of glasses with a machine vision camera, that flashes a light when it detects an object in its field of view associated with a calendar entry.

At its heart is a JeVois A33 Smart Machine Vision Camera, which runs a neural network trained on an image dataset. It passes its sightings to an Arduino Nano IoT fitted with a real-time clock, that pulls appointment information from Google Calendar and flashes the LED when it detects a match between object and event. His example which we’ve placed below the break is a pill bottle triggering a reminder to take the pills.

We like this idea, but can’t help thinking that it has a flaw in that the reminder relies on the object moving into view. A version that tied this in with more conventional reminding based upon the calendar would address this, and perhaps save the forgetful a few problems.

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