Aireon Hitchhikes On Iridium To Track Airplanes

December 27, 2017 by Roger Cheng 21 Comments

SpaceX just concluded 2017 by launching 10 Iridium NEXT satellites. A footnote on the launch was the “hosted payload” on board each of the satellites: a small box of equipment from Aireon. They will track every aircraft around the world in real-time, something that has been technically possible but nobody claimed they could do it economically until now.

Challenge one: avoid adding cost to aircraft. Instead of using expensive satcom or adding dedicated gear, Aireon listen to ADS-B equipment already installed as part of international air traffic control modernization. But since ADS-B was designed for aircraft-to-aircraft and aircraft-to-ground, Aireon had some challenges to overcome. Like the fact ADS-B antenna is commonly mounted on the belly of an aircraft blocking direct path to satellite.

Challenge two: hear ADS-B everywhere and do it for less. Today we can track aircraft when they are flying over land, but out in the middle of the ocean, there are no receivers in range except possibly other aircraft. Aireon needed a lot of low-orbit satellites to ensure you are in range no matter where you are. Piggybacking on Iridium gives them coverage at a fraction of the cost of building their own satellites.

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Geocache Locator Is The Gift That Keeps On Giving

December 18, 2017 by Tom Nardi 5 Comments

Depending on how you look at things, the holidays could be seen as either an excuse to spend money or an excuse to get creative. We imagine many Hackaday readers would rather head to their workbench than the mall when it comes time for gift giving, and [Sean Hodgins] is no different. He came up with the idea of hiding geocaches around his nephew’s neighborhood and building him a locator device to find them. The locator itself is intended to grow with his nephew, allowing him to reprogram it or use its parts for something completely different down the road.

The main components tucked inside of the 3D printed case of the locator are an Adafruit Trinket, a GPS receiver, and a compass module. The Adafruit NeoPixel Ring is of course front and center, serving as the device’s display. To power the device there’s an old battery, a LiPo charger circuit, and a 5V converter.

One of the goals for the project was that it could be constructed out of things [Sean] already had laying around, so some concessions had to be made. The Trinket ended up having too few pins, the compass lacks an accelerometer, and the switches and buttons are a bit clunky for the build. But in the end it comes together well enough to get the job done, and at least he was able to clear some stuff out of his parts bins.

To allow its owner to disassemble and potentially rebuild it into something else later, no soldered joints were used in the construction of the locator. Everything is done with jumper wires, which lead to some interesting problem solving such as using a strip of pin header as a bus bar of sorts. A bit of heat shrink over the bundle holds everything together and prevents shorts.

Location-aware gadgets happen to be an extremely popular gift choice among the hacker crowd. We’ve covered everything from devices cobbled together from trash to hardware which could pass for a commercial product.

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A Teardown Of Something You Should Not Own

December 1, 2017 by Brian Benchoff 67 Comments

GPS jammers are easily available on the Internet. No, we’re not linking to them. Nevertheless, GPS jammers are frequently used by truck drivers and other people with a company car that don’t want their employer tracking their every movement. Do these devices work? Are they worth the $25 it costs to buy one? That’s what [phasenoise] wanted to find out.

These tiny little self-contained boxes spew RF at around 1575.42 MHz, the same frequency used by GPS satellites in high Earth orbit. Those signals coming from GPS satellites are very, very weak, and it’s relatively easy to overpower them with noise. That’s pretty much the block diagram for these cheap GPS jammers — put some noise on the right frequency, and your phone or your boss’s GPS tracker simply won’t function. Note that this is a very low-tech attack; far more sophisticated GPS jamming and spoofing techniques can theoretically land a drone safely.

[phasenoise]’s teardown of the GPS jammer he found on unmentionable websites shows the device is incredibly simple. There are a few 555s in there creating low-frequency noise. This feeds a VCO with a range of between 1466-1590 MHz. The output of the VCO is then sent to a big ‘ol RF transistor for amplification and out through a quarter wave antenna. It may be RF wizardry, but this is a very simple circuit.

The output of this circuit was measured, and to the surprise of many, there were no spurious emissions or harmonics — this jammer will not disable your cellphone or your WiFi, only your GPS. The range of this device is estimated at 15-30 meters in the open, which is good enough if you’re a trucker. In the canyons of skyscrapers, this range could extend to hundreds of meters.

It should be said again that you should not buy or use a GPS jammer. Just don’t do it. If you need to build one, though, they’re pretty easy to design as [phasenoise]’s teardown demonstrates.

Distributed Air Quality Monitoring Via Taxi Fleet

November 20, 2017 by Kristina Panos 11 Comments

When [James] moved to Lima, Peru, he brought his jogging habit with him. His morning jaunts to the coast involve crossing a few busy streets that are often occupied by old, smoke-belching diesel trucks. [James] noticed that his throat would tickle a bit when he got back home. A recent study linking air pollution to dementia risk made him wonder how cities could monitor air quality on a street-by-street basis, rather than relying on a few scattered stations. Lima has a lot of taxis, so why wire them up with sensors and monitor the air quality in real-time?

This taxi data logger’s chief purpose is collect airborne particulate counts and illustrate the pollution level with a Google Maps overlay. [James] used a light-scattering particle sensor and a Raspi 3 to send the data to the cloud via Android Things. Since the Pi only has one native UART, [James] used it for the particle sensor and connected the data-heavy GPS module through an FTDI serial adapter. There’s also a GPS to locate the cab and a temperature/humidity/pressure sensor to get a fuller environmental picture.

Take a ride past the break to go on the walk through, and stick around for the testing video if you want to drive around Lima for a bit. Interested in monitoring your own personal air quality? Here’s a DIY version that uses a dust sensor.

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Snail Is Actually Cleverly Strange Geocaching Waypoint

November 11, 2017 by Donald Papp 12 Comments

Basic geocaching consists of following GPS coordinates to a location, then finding a container which is concealed somewhere nearby. Like any activity, people tend to add their own twists to keep things interesting. [Jangeox] recently posted a video of the OLED Snail 2.0 to show off his most recent work. (This is a refinement of an earlier version, which he describes in a blog post.)

Another of [Jangeox]’s Electronic Waypoints

[Jangeox] spices up geocaching by creating electronic waypoints, and the OLED Snail is one of these. Instead of GPS coordinates sending someone directly to a goal, a person instead finds a waypoint that reveals another set of coordinates and these waypoints are followed like a trail of breadcrumbs.

A typical waypoint is an ATTINY85 microcontroller programmed to display an animated message on the OLED, and the message reveals the coordinates to the next waypoint. The waypoint is always cleverly hidden, and in the case of the OLED Snail 2.0 the enclosure is the shell of a large snail containing the electronics encased in resin. This means that the devices have a finite lifespan — the battery sealed inside is all the power the device gets. Fortunately, with the help of a tilt switch the electronics can remain dormant until someone picks it up to start the show. Other waypoints have included a fake plant, and the fake bolt shown here. Video of the OLED Snail 2.0 is embedded below.

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Hackaday Prize Entry: Global Positioning Clock

October 27, 2017 by Brian Benchoff 30 Comments

How do you get the attention of thousands of Hackaday readers? Build a clock! There are just so many choices to agonize over. Do you go with a crystal as a clock source, a fancy oven controlled crystal oscillator, or just mains voltage? Should you even think about putting a GPS module in a clock? All these are very interesting questions that encourage discussion or learning, and that’s what Hackaday is all about. Clocks are cool, and the engineering behind them is even cooler.

For one of [Nick]’s Hackaday Prize entries, he’s building a minimalist GPS clock. First up, the centerpiece of every clock, the display. There are eight seven-segment displays, two each for the hours, minutes, and seconds, and a smaller digit for tenths of a second. These displays are controlled by an ATXmega32E5, an upgrade on an earlier version of this project that only used an ATtiny and a MAX6951 LED driver.

The GPS wizardry is where this project gets really cool. [Nick] is using a SkyTraq Venus838LPx-T (that’s also available on a breakout board on Tindie). This GPS chip has a handy edge mount SMA connector to receive the signals from a GPS satellite, and has a bidirectional UART to dump the NMEA time codes and a PPS output. By combining the timecode, PPS output, and playing around with the timers on the microcontroller, [Nick] has a fantastically accurate clock that also looks great.

Don’t Miss Watching This Solar Eclipse High Altitude Balloon Online

August 20, 2017 by Donald Papp 8 Comments

[Dan Julio] let us know about an exciting project that he and his team are working on at the Solid State Depot Makerspace in Boulder: the Solar Eclipse High Altitude Balloon. Weighing in at 1 kg and bristling with a variety of cameras, the balloon aims to catch whatever images are able to be had during the solar eclipse. The balloon’s position should be trackable on the web during its flight, and some downloaded images should be available as well. Links for all of that are available from the project’s page.

High altitude balloons are getting more common as a platform for gathering data and doing experiments; an embedded data recorder for balloons was even an entry for the 2016 Hackaday Prize.

If all goes well and the balloon is able to be recovered, better images and video will follow. If not, then at least a post-mortem of what the team thinks went wrong will be posted. Launch time in Wyoming is approximately 10:40 am ~~Mountain Time (UTC -07:00)~~ Mountain Daylight Time (UTC -06:00) on Aug 21 2017, so set your alarm!