Handheld GPS Tracks All The Things

February 19, 2018 by 9 Comments

With a GPS on every smartphone, one would be forgiven for forgetting that handheld GPS units still exist. Seeking to keep accurate data on a few upcoming trips, [_Traveler] took on a custom-build that resulted in this GPS data logger.

Keeping tabs on [_Traveler] is a Ublox M8N GPS which is on full-time, logging data every 30 seconds, for up  to 2.5 days. All data is saved to an SD card, with an ESP32 to act as a brain and make downloading the info more accessible via WiFi . While tracking the obvious — like position, speed, and time — this data logger also displays temperature, elevation, dawn and dusk, on an ePaper screen which is a great choice for conserving battery.

The prototyping process is neat on this one. The first complete build used point-to-point soldering on a protoboard to link several breakout modules together. After that, a PCB design embraces the same modules, with a footprint for the ESP’s castellated edges and header footprints for USB charing board, SD card board, ePaper, etc. All of this finds a hope in a 3D printed enclosure. After a fair chunk of time coding in the Arduino IDE the logger is ready for [_Traveler]’s next excursion!

As far as power consumption in the field, [_Traveler] says the GPS takes a few moments to get a proper location — with the ESP chewing through battery life all the while — and plans to tinker with it in shorter order.

Not all GPS trackers are created equal: sometimes all you need is a stripped-down tracker for your jog, or to know exactly where every pothole is along your route.

[Via /r/electronics]

You All Know Reginald Fessenden. Who?

February 19, 2018 by 30 Comments

Quick, name someone influential in the history of radio. Who do did you think of? Marconi? Tesla? Armstrong? Hertz? Perhaps Sarnoff? We bet only a handful would have said Reginald Fessenden. That’s a shame because he was the first to do something that most of us do every day.

Few know this Canadian inventor’s name even though he developed quite a few innovations. Unlike Colpitts and Hartley we don’t have anything named after him. However, Fessenden was the first man to make a two-way transatlantic radio contact (Marconi’s was one way) and he was a pioneer in using voice over the radio.

He did even more than that. He patented transmitting with a continuous wave instead of a spark, which made modern radio practical. This was unpopular at the time because most thought the spark was necessary to generate enough energy. In 1906, John Fleming (who gave us tubes that are sometimes still called Fleming valves) wrote that “a simple sine-curve would not be likely to produce the required effect.” That was in 1906, five years after Fessenden’s patent.

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Predicting Starman’s Return To Earth

February 19, 2018 by 31 Comments

There’s a Starman, waiting in the sky. He’d like to come and meet us, but he’ll have to wait several million years until the Yarkovsky effect brings him around to Earth again.

In case you’ve been living under a rock for the past few weeks, SpaceX recently launched a car into space. This caused much consternation and hand-wringing, but we got some really cool pictures of side boosters landing simultaneously. The test launch for the Falcon Heavy successfully lobbed a Tesla Roadster into deep space with an orbit extending out into the asteroid belt. During the launch coverage, SpaceX said the car would orbit for Billions of years. This might not be true; a recent analysis of the random walk of cars revealed a significant probability of hitting Earth or Venus over the next Million years.

The analysis of the Tesla Roadster relies on the ephemerides provided by JPL’s Horizons database (2018-017A), and predicts the orbit over several hundred years. In the short term — a thousand years or so — there is little chance of a collision with anything. In 2091, however, the Tesla will find itself approaching Earth, and after that, the predicted orbits change drastically. As an aside, we should totally bring the Tesla back in 2091.

Even though the Tesla Roadster, its payload adapter, and the booster are inert objects floating in space right now, that doesn’t mean there aren’t forces acting on it. For small objects orbiting near the sun, the Yarkovsky effect is a huge influence on the orbit when measured on a timescale of millennia. In short, the Yarkovsky effect is a consequence of a spinning object being heated by the sun. As an object (a Tesla, or an asteroid) rotates, the side facing the sun heats up. As this side faces away from the sun, this heat is radiated out, imparting a tiny, tiny force. This force, over a period of millions of years, can send the Tesla into resonances with other planets, eventually sending it crashing into Earth, Venus, or the Sun.

The authors of this paper find there is a 6% chance the Tesla will collide with Earth and a 2.5% chance it will collide with Venus in the next one Million years. In three Million years, the probability of a collision with Earth is 11%. These are, according to the authors, extremely preliminary calculations and more observations are needed. If the Tesla were to hit the Earth, it’s doubtful whatever species populates the planet would notice; the mass of the Tesla is only 1250 Kg, and Earth flies through meteoroids weighing that much very frequently.

Milspec Teardown: CP-142 Range Computer

February 19, 2018 by 69 Comments

As some of my previous work here at Hackaday will attest to, I’m a big fan of World War II technology. Something about going in with wooden airplanes and leaving with jet fighters and space capable rockets has always captivated me. So when one of my lovingly crafted eBay alerts was triggered by something claiming to be a “Navy WWII Range Computer”, it’s safe to say I was interested.

Not to say I had any idea of what the thing was, mind you. I only knew it looked old and I had to have it. While I eagerly awaited the device to arrive at my doorstep, I tried to do some research on it and came up pretty much empty-handed. As you might imagine, a lot of the technical information for hardware that was developed in the 1940’s hasn’t quite made it to the Internet. Somebody was selling a technical manual that potentially would have covered the function of this device for $100 on another site, but I thought that might be a bit excessive. Besides, where’s the fun in that?

I decided to try to decipher what this device does by a careful examination of the hardware, consultation of what little technical data I could pull up on its individual components, and some modern gear. In the end I think I have a good idea of how it works, but I’d certainly love to hear if there’s anyone out there who might have actually worked with hardware like this and could fill in any blanks.

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The White Rabbit Nixie Clock

February 19, 2018 by 20 Comments

Instructables user [hellboy] — a recent convert to the ways of the laser cutter — is a longtime admirer of Nixie tubes. In melding these two joys, he has been able to design and build this gorgeous work of art: The White Rabbit Nixie Clock.

Going into this build, [hellboy] was concerned over the lifespan of the tubes, and so needed to be able to turn them off when not needed. Discarding their original idea of having the clock open with servos, [hellboy]’s clock opens by pressing down on a bar and is closed by snapping the lid shut — albeit slightly more complicated than your average timepiece. Given the intricacy of the mechanism, he had to run through numerous prototypes — testing, tweaking and scrapping parts along the way.

With the power of steam-bending, [hellboy] lovingly moulded walnut planks and a sundry list of other types of wood to define the ‘rabbit’ appearance of the mechanism, and the other parts of the clock’s case. Once again, designing the clock around a row of six pivoting Nixie tubes was no mean feat — especially, as [hellboy] points out, when twenty or so wires need to rotate with them! After a few attempts, the Nixie tubes, their 3mm blue LEDs and associated wires were properly seated.

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Roll Your Own Rotary Encoders

February 19, 2018 by 36 Comments

[miroslavus] hasn’t had much luck with rotary encoders. The parts he has tested from the usual sources have all been problematic either mechanically or electrically, resulting in poor performance in his projects. Even attempts to deal with the deficiencies in software didn’t help, so he did what any red-blooded hacker would do — he built his own rotary encoder from microswitches and 3D-printed parts.

[miroslavus]’s “encoder” isn’t a quadrature encoder in the classic sense. It has two switches and only one of them fires when it turns a given direction, one for clockwise and one for counterclockwise. The knob has a ratchet wheel on the underside that engages with a small trip lever, and carefully located microswitches are actuated repeatedly as the ratchet wheel moves the trip lever. The action is smooth but satisfyingly clicky. Personally, we’d forsake the 3D-printed baseplate in favor of a custom PCB with debouncing circuitry, and perhaps relocate the switches so they’re under the knob for a more compact form factor. That and the addition of another switch on the shaft’s axis to register knob pushes, and you’ve got a perfectly respectable input device for navigating menus.

We think this is great, but perhaps your project really needs a legitimate rotary encoder. In that case, you’ll want to catch up on basics like Gray codes.

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Hackaday Dublin Unconference: Grab Your Tickets!

February 18, 2018 by 20 Comments

Hackaday comes together in Ireland on April 7th and we want you to be there. Get your free ticket right now for the Hackaday Dublin Unconference!

An Unconference is the best way to put your finger on the pulse of what is happening in the hardware world right now. Everyone who attends should be ready to stand and deliver a seven-minute talk on something that excites them right now — this means you. The easiest thing to do is grab your latest hack off the shelf and talk about that.

Talks may be about a prototype, project, or product currently in progress at your home, work, or university. It could also be an idea, concept, or skill that you’re now exploring. The point is to channel your excitement and pass it on to others in a friendly presentation environment where everyone will cheer as your story unfolds.

Hackaday hosted an excellent Unconference in London back in September to a packed house for dozens of amazing presentations on a huge range of topics. We heard about bicycle turn signals, laser enhancing NES zappers, telepresence robots with IKEA origin stories, tiny-pitch LED matrix design, driving flip-dot displays, not trusting hardware 2-factor, and much more.

All the tickets for that event were scooped up in a few hours, and a huge waitlist followed. Don’t wait to grab your ticket!

We’re so happy to partner with DesignSpark, the exclusive sponsor of the Hackaday Dublin Unconference. DesignSpark is the innovation arm of RS Components and will have some staff on hand at the Unconference. They share our excitement in bringing together the Hackaday community throughout Europe. It is with their support that we are able to book an incredible venue and offer admission at no cost to all attendees. Hackaday events fill to capacity quickly, so get your ticket now before they are gone.

This Unconference is being held at Project Arts Centre, right at the heart of the Temple Bar area in central Dublin. The performing arts space has comfortable seating and is perfect for our presentation format. We’ll get started at 13:00. Tea, coffee, and snacks will be served throughout the afternoon and we’ll provide dinner as well. Anyone who is still standing when we close the doors at 21:00 is invited to join us at the pub afterward (we’ll get the first round).

As always, Hackaday’s success is based on the community of hackers, designers, and engineers that make it up. Please share the link to tickets on your social media and pester your friends to attend. Most importantly, don’t shy away from this speaking opportunity. We want to hear your story and this is the place to tell it. See you in Dublin in just a few short weeks!