Bike Computer Powers On Long After Your Legs Give Out

August 20, 2020 by Brian McEvoy 13 Comments

A typical bicycle computer from the store rack will show your speed, trip distance, odometer, and maybe the time. We can derive all this data from a magnet sensor and a clock, but we live in a world with all kinds of sensors at our disposal. [Matias N.] has the drive to put some of them into a tidy yet competent bike computer that has a compass, temperature, and barometric pressure.

The brains are an STM32L476 low-power controller, and there is a Sharp Memory LCD display as it is a nice compromise between fast refresh rate and low power. E-paper would be a nice choice for outdoor readability (and obviously low power as well) but nothing worse than a laggy speedometer or compass.

In a show of self-restraint, he didn’t try to replace his mobile phone, so there is no GPS, WiFi, or streaming music. Unlike his trusty phone, you measure the battery life in weeks, plural. He implemented EEPROM memory for persistent data through power cycles, and the water-resistant board includes a battery charging circuit for easy topping off between rides.

When you toss the power of a mobile phone at a bike computer, someone will unveil the Android or you can measure a different kind of power from your pedals.

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Automatic Planet Finder Is Out Of This World

June 5, 2020 by Kristina Panos 5 Comments

When the world is on your shoulders, it can be relaxing to remember that we’re just hairless monkeys hurtling through space on a big rock alongside a lot of other rocks. If you find yourself wondering where exactly the other major rocks are instead of worrying, we think that’s a good sign.

Wherever [snowbiscuit] lives, there’s a large planet finder in a public square somewhere that stopped locating rocks a long time ago. Hungry to watch such a thing in action, [snowbiscuit] built a great-looking tabletop version that uses the Horizontal Coordinate System to locate planets. Inside is a Raspberry Pi 3, which queries NASA for azimuth and altitude data and combines that data with a predetermined north reading to point out whatever planet was selected by spinning the printed telescope on top. The telescope itself is non-working, and returns to north after a few seconds to wait for input.

This project is wide open for remixing if you want to make your own. As lovely as it is now, designing around a slip ring would eliminate all those long wires and make it more sleek. Take a peek after the break.

Don’t stop your desktop space toy collection there — build an ISS-tracking lamp to go with it.

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Replace Your Smartphone With These Arcane Amulets

December 19, 2019 by Gerrit Coetzee 17 Comments

It’s hard not to feel the constant pull on our limited attention from the very interesting rectangles in our pockets and packs. [Antoine Pintout] is fighting against it with three interesting pendants.

The three objects each have functions. Sablier, tells time, but rather than giving the numerals it vibrates on a set interval to give a relative sense of the passage. Boussole is a compass like device which doesn’t tell the cardinal directions. Instead it tells you which way to go in order to get to a pre-set location. The last, Sifflet, is a pager, but rather than sending a text it plays a melody reflecting the sender’s mood.

We love the look of the objects. The circuits are beautifully laid out and showcased in well machined brass cases. Small details abound; in Sifflet for example, the coil antenna is symmetrically presented with its own cutout in the board. Laying out a board is hard enough, but taking this much care in component placement easily doubles the time.

All the files and models are available, though we’re not sure we possess the craftsmanship to reproduce these to the same standard.

A Stylish Solution For Bike Navigation

May 29, 2019 by Tom Nardi 7 Comments

[André Biagioni] is developing an open hardware bicycle navigation device called Aurora that’s so gorgeous it just might be enough to get you pedaling your way to work. This slick frame-mounted device relays information to the user through a circular array of SK6812 RGB LEDs, allowing you to find out what you need to know with just a quick glance down. No screen to squint at or buttons to press.

The hardware has already gone through several revisions, which is exactly what we’d expect to see for an entry into the 2019 Hackaday Prize. The proof of concept that [André] zip-tied to the front of his bike might have worked, but it wasn’t exactly the epitome of industrial design. It was enough to let him see that the idea had merit, and from there he’s been working on miniaturizing the design.

So how does it work? The nRF52832-powered Aurora connects to your phone over Bluetooth, and relays turn-by-turn navigation information to you via the circular LED array. This prevents you from having to fumble with your phone, which [André] hopes will improve safety. When you’re not heading anywhere specific, Aurora can also function as a futuristic magnetic compass.

With what appears to be at least three revisions of the Aurora hardware already completed by the time [André] put the project up on Hackaday.io, we’re very interested in seeing where it goes from here. The theme for this year’s Hackaday Prize is moving past the one-off prototype stage and designing something that’s suitable for production, and so far we’d say the Aurora project is definitely rising to the challenge.

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Do You Know Where Your Drone Is Headed? HJWYDK Article Explores Limits Of MEMS Sensors

March 12, 2019 by Ted Yapo 28 Comments

Knowing in what absolute direction your robot is pointed can be crucial, and expensive systems like those used by NASA on Mars are capable of calculating this six-dimensional heading vector to within around one degree RMS, but they are fairly expensive. If you want similar accuracy on a hacker budget, this paper shows you how to do it using cheap MEMS sensors, an off-the-shelf motion co-processor IC, and the right calibration method.

The latest article to be published in our own peer-reviewed Hackaday Journal is Limits of Absolute Heading Accuracy Using Inexpensive MEMS Sensors (PDF). In this paper, Gregory Tomasch and Kris Winer take a close look at the heading accuracy that can be obtained using several algorithms coupled with two different MEMS sensor sets. Their work shows that when properly used, inexpensive sensors can produce results on par with much more costly systems. This is a great paper that illustrates the practical contributions our community can make to technology, and we’re proud to publish it in the Journal.

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Ask Hackaday: Earth’s Magnetic Field Shifting Rapidly, But Who Will Notice?

March 6, 2019 by Jenny List 92 Comments

Just when you though it was safe to venture out, the National Oceanic and Atmospheric Administration released an unexpected update. Magnetic North is on the move — faster than expected. That’s right, we know magnetic north moves around, but now it’s happened at a surprising rate. Instead of waiting for the normal five year interval before an update on its position, NOAA have given us a fresh one a bit earlier.

There are some things that we can safely consider immutable, reliable, they’ll always be the same. You might think that direction would be one of them. North, south, east, and west, the points of the compass. But while the True North of the Earth’s rotation has remained unchanged, the same can not be said of our customary method of measuring direction.

Earth’s magnetic field is generated by a 2,000 km thick outer core of liquid iron and nickel that surrounds the planet’s solid inner core. The axis of the earth’s internal magnet shifts around the rotational axis at the whim of the currents within that liquid interior, and with it changes the readings returned by magnetic compasses worldwide.

The question that emerged at Hackaday as we digested news of the early update was this: as navigation moves inexorably towards the use of GPS and other systems that do not depend upon the Earth’s magnetic field, where is this still relevant beyond the realm of science?

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A Low Cost VR Headset

January 3, 2019 by Bryan Cockfield 3 Comments

Virtual reality systems have been at the forefront of development for several decades. While there are commercial offerings now, it’s interesting to go back in time to when the systems were much more limited. [Colin Ord] recently completed his own VR system, modeled on available systems from 20-30 years ago, which gives us a look inside what those systems would have been like, as well as being built for a very low cost using today’s technology.

The core of this project is a head tracker, which uses two BBC Microbits as they have both the accelerometer and compass needed to achieve the project goals. It is also capable of tracking an item and its position in the virtual space. For this project, [Colin] built everything himself including the electronics and the programming. It also makes use of Google Cardboard to hold the screen, lenses, and sensors all in the headset. All of this keeps the costs down, unlike similar systems when they were first unveiled years ago.

The ground-up approach that this project takes is indeed commendable. Hopefully we can see the code released, and others can build upon this excellent work. You could even use it to take a virtual reality cycling tour of the UK.

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