In 1971, the United States Navy launched the Omega navigational system for submarines and surface ships. The system used radio frequencies and phase difference calculations to determine global position. A network of eight (VLF) transmitter sites spread around the globe made up the system, which required the cooperation of six other nations.
Omega’s fix accuracy was somewhere between one and two nautical miles. Her eight transmitter stations were positioned around the Earth such that any single point on the planet could receive a usable signal from at least five stations. All of the transmitters were synchronized to a Cesium clock and emitted signals on a time-shared schedule.
A ship’s receiving equipment performed navigation by comparing the phase difference between detected signals. This calculation was based around “lanes” that served to divvy up the distance between stations into equal divisions. A grid of these lanes formed by eight stations’ worth of overlapping signals provides intersecting lines of position (LOP) that give the sailor his fix.
In order for the lane numbers to have meaning, the sailor has to dial in his starting lane number in port based on the maps. He would then select the pair of stations nearest him, which were designated with the letters A to H. He would consult the skywave correction tables and make small adjustments for atmospheric conditions and other variances. Finally, he would set his lane number manually and set sail.
Continue reading “Retrotechtacular: The Omega Navigational System”
For the last few weeks we’ve been celebrating builds that use parts from our manufacturer sponsors of the 2015 Hackaday Prize. Today we are happy to announce 50 winners who used Freescale parts in their builds. Making the cut is one thing, but rising to the top is another. These builds show off some amazing work from those who entered them. In addition to the prizes which we’ll be sending out, we’d like these projects to receive the recognition they deserve. Please take the time to click through to the projects, explore what has been accomplished, and leave congratulations a comment on the project page.
Still Time to Win!
We’re far from the end of the line. We’ll be giving roughly $17,000 more in prizes before the entry round closes in the middle of August. Enter your build now for a chance in these weekly contests! This week we’re looking for things that move in our Wings, Wheels, and Propellers Contest.
One voter will win $1000 from the Hackaday Store this week as well! Anyone is welcome to vote in Astronaut or Not. The drawing is this afternoon, Vote Now!
Continue reading “50 Winners Using Freescale Parts”
This is your 90-minute warning. This week’s Collabatorium begins in just 1.5 hours and you’re invited. To join in just click the “Request to join this project” found on the left sidebar of the Hacker Channel page.
Once you’ve joined you can open up the Group Messaging for that project, one of the many awesome collaboration features on Hackaday.io. Starting at 1700 UTC we’ll launch the Collabatorium to celebrate, discuss, encourage, and find partners for 2015 Hackaday Prize Entries. This edition of the live event is hosted by [Sophi Kravitz] and [Jasmine Brackett].
While we have your attention, here’s another reminder to head on over and Vote in Astronaut or Not. Each week we draw a random hacker number for a $1000 giveaway, but only if you have voted!. The next drawing is TODAY so get at least one vote in right away to qualify.
Like it or not, Hackers gonna hack. And when your hackerspace has someone who looks like Doc Brown from Back to the Future, the builds can get a bit weird, like this Hack42 FestivalCharger.
The Hack42 hackerspace in Arnhem, The Netherlands had collected a large number of TP-Link 5V USB chargers – but all of them had the North American NEMA plug (flat, 2 pin) which wouldn’t fit the Schuko sockets prevalent in The Netherlands. [Simon “MacSimski” Claessen] decided to whip out his giant soldering iron and use it to solder two long pieces of welding filler metal rods to 33 of the chargers, effectively wiring them up in parallel. He did apply his obvious skill and experience to good use. For one, the diameter of the filler metal rods he used were just about the right size to fit in the
Shucko Schuko socket. And the gap between the two turned out to be the right distance too, thus creating a sort of Schucko Schuko plug. All that was needed to power up all the chargers was to connect a socket extension to the FestivalCharger. The unit was built to allow crowds of festival-goers to charge their phones and battery-powered gadgets simultaneously. To make sure the visitors didn’t get electrocuted, he used a piece of PVC pipe to cover up the exposed pins and keep it all safe.
Thanks to Hack42 member [Dennis van Zuijlekom] for sending in this tip.
It’s a bit scary what you can make with stuff found in the average household, provided you know what you’re doing. How about a TEA laser? Don’t have a high-voltage power supply to run it? Do what [Steven] of rimstar.org did, and power it with a homemade Wimshurst machine.
TEA lasers give off ultraviolet light. In order to see the beam, [Steven] aims it through a glass of water tinted with highlighting-marker juice and onto a sheet of white paper. [Steven] originally used his homemade 30kV DC power supply to light up his TEA laser. He made the laser itself from aluminium foil, angled aluminium, transparency sheets, some basic hardware components, and a 100kΩ resistor.
Although the components are simple, adjusting them so that the laser actually works is quite a feat. [Steven] says he burned holes through several transparencies and pieces of foil before getting it right. Using a Wimshurst machine to power the TEA laser takes another level of patience. It takes about 25 cranks of the static electricity-producing machine to build up enough energy to attempt lasing.
Want to make your own TEA laser, perhaps in a different configuration? [Steven]’s design was based on one of [sparkbangbuzz]’s lasers, which we covered several years ago.
Continue reading “Legit Hack Creates TEA Laser Power by Mr. Wimshurst”
When you have access to your own CNC machine, you tend to make stuff first and ask questions later. That sounds like how [Rui Cabral] came up with a weather station stuffed into a miniature arcade game cabinet.
Standing only about 16 cm tall, the cabinet is quite detailed and resembles the familiar arcade form factor that has consumed countless quarters. It even appears to be made of particle board like the big boys. The screen cutout is filled by a 84×48 monochrome Nokia display, and the rest of the cabinet’s interior is stuffed with a CNC-milled PCB, temperature and humidity sensors, an RTC, and a Bluetooth module for uploading data to a phone. [Rui] even manages to work in an homage to the grand-daddy of all arcade games with a Pong splash screen.
Another good-looking display for this project might have been this ePaper badge made into a weather station. And we’ve featured even tinier arcade cabinets too, though perhaps not as functional.
[Rui] takes us on a video tour of his build after the break.
Continue reading “Coin-Op Weather”
Beats headphones are very popular, they’re everywhere, and they sound like trash. That’s a shame, because there’s a century of recorded music out there that sounds really good. [WΛLLTΞCH] forgot about [Dre] and started looking into a better way to listen to music. He came up with bone conduction transducers and started one of the most interesting projects for this year’s Hackaday Prize.
Instead of driving a speaker cone that vibrates the air, passes through the middle ear, and vibrates the eardrum, bone conduction amplifiers bypass the outer and middle ear completely. Not only does this produce a clearer reproduction of sound, but it’s also great for anyone with an abnormality in the ear canal, ear drum, or the tiny bones of the inner ear.
[WΛLLTΞCH]’s first prototype is using a bone conduction amplifier and a cheap Bluetooth module, stuffed into a small 3D printed case. With two 1W transducer modules, it was enough for a proof of concept. The final design is vastly more integrated, with a dedicated Bluetooth audio module. To this, [WΛLLTΞCH] is adding microphones and the ability to take calls over Bluetooth. It’s a great project, and something that could make a great product, something we’re also looking for in this year’s Hackaday Prize.