If you mention a clock that receives its time via radio, most people will think of one taking a long wave signal from a station such as WWVB, MSF, or DCF77. A more recent trend however has been for clocks that set themselves from orbiting navigation satellites, and an example comes to us from [KK99]. It’s a relatively simple hardware build in that it is simply an Arduino Nano, GPS module, and e-ink display module wired together, but it provides an interesting exercise in running through the code required for a GPS clock.
It does however give us a chance to remember the story from last year surrounding WWVB, as a budget proposal last year mooted the prospect of the closure of the Fort-Collins-based time signal transmitter. Were that to happen an estimated 50 million American clocks would lose their reference, and while their owners could always update them manually, there will always be time-based systems to which that won’t be applied for whatever reason. Europeans meanwhile are safe in their time transmissions for now , but in case they think they have their mains grid to fall back on it’s worth remembering the time they lost six seconds.
There’s a bug about to hit older GPS hardware that has echos of Y2K. Those old enough to have experienced the transition from the 1990s to the 2000s will no doubt recall the dreaded “Year 2000 Bug” that was supposed to spell the doom of civilization. Thanks to short-sighted software engineering that only recorded two digits for year, we were told that date calculations would fail en masse in software that ran everything from the power grid to digital watches. Massive remediation efforts were undertaken, companies rehired programmers whose outdated skills were suddenly back in demand, and in the end, pretty much nothing actually happened.
Yet another epoch is upon us, far less well-known but potentially deeper and more insidious. On Saturday April 6, 2019 — that’s tomorrow — GPS receivers may suffer from software issues due to rollover of their time counters. This could result in anything from minor inconvenience to major confusion, with an outside chance of chaos. Some alarmists are even stating that they won’t fly this weekend, for fear of the consequences.
So what are the real potential consequences, and what’s the problem with GPS in the first place? Unsurprisingly, it all boils down to basic math.
The Cope brothers are our hosts this week. Jeremy, a computer engineer, and Jason, a mechanical engineer, have recently caught the high-altitude ballooning (HAB) bug. In their initial flights they’ve racked up some successes and pushed the edge of space with interesting and varied missions. Their first flight just barely missed the 100,000 foot (30,000 meter) mark and carried a simple payload package of cameras and GPS instruments and allowed them to reach their goal of photographing the Earth’s curvature.
Flight 2 had a similar payload but managed to blow through the 100K foot altitude, capturing stunning video of the weather balloon breaking. Their most recent flight carried a more complex payload package, consisting of the usual camera and GPS but also a flight data recorder of their own devising, as well as a pair of particle detectors to measure the change in flux of subatomic particles with increasing altitude. That flight “only” reached 62,000 ft (19,000 meters) but managed to hitch a ride on the jet stream that nearly took the package out to sea.
The Cope brothers will be joining the Hack Chat to talk about the exciting field of DIY high-altitude ballooning and the challenges of getting a package halfway to space (depending on how that’s defined). Please join us as we discuss:
The basics of flight – balloons, rigging, payload protection, tracking, and recovery;
Getting started on the cheap;
Making a flight into a mission with interesting and innovative ideas for payload instrumentation;
Will hobbyist HABs ever break the Kármán Line? and
You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the High-Altitude Ballooning Hack Chat event page and we’ll put that in the queue for the Hack Chat discussion.
There’s something compelling about high-altitude ballooning. For not very much money, you can release a helium-filled bag and let it carry a small payload aloft, and with any luck graze the edge of space. But once you retrieve your payload package – if you ever do – and look at the pretty pictures, you’ll probably be looking for the next challenge. In that case, adding a little science with this high-altitude muon detector might be a good mission for your next flight.
[Jeremy and Jason Cope] took their inspiration for their HAB mission from our coverage of a cheap muon detector intended exactly for this kind of citizen science. Muons constantly rain down upon the Earth from space with the atmosphere absorbing some of them, so the detection rate should increase with altitude. [The Cope brothers] flew two of the detectors, to do coincidence counting to distinguish muons from background radiation, along with the usual suite of gear, like a GPS tracker and their 2016 Hackaday prize entry flight data recorder for HABs.
The payload went upstairs on a leaky balloon starting from upstate New York and covered 364 miles (586 km) while managing to get to 62,000 feet (19,000 meters) over a five-hour trip. The [Copes] recovered their package in Maine with the help of a professional tree-climber, and their data showed the expected increase in muon flux with altitude. The GoPro died early in the flight, but the surviving footage makes a nice video of the trip.
Imagine if you bought a new car but they keys were not going to be shipped to you until a few years later. That’s analogous to the situation the U.S. Air Force finds itself in. The first GPS III satellite is finally ready to launch today, December 18, 2018 — a little over 2 years beyond the original schedule. However, most of the unique GPS III features won’t be available until at least 2022, according to a 2017 Government Accounting Office (GAO) report to Congress.
GPS III is a project to launch 32 new satellites that will — for military users — be more difficult to jam. For civilian users, the new GPS satellites will be compatible with other systems, including the EU’s Galileo system. But the big draw? About three times the accuracy of the current system. For civilian use, that means 3 to 10 feet under good conditions as opposed to the current systems’ 10- to 33-foot resolution.
[Mark Rober] was fed up with packages going missing. He kept receiving notifications that his shipments had been delivered, but when checking his porch he found nothing there. Reviewing the CCTV footage revealed random passers-by sidling up to his porch and stealing his parcels. It was time to strike back. Over six months, [Mark] and his friends painstakingly designed, prototyped and iterated the perfect trap for package thieves, resulting in a small unit disguised as an Apple HomePod. The whole scheme is wonderfully over-engineered and we love it.
The main feature of the device is a spinning cup on the top which contains a large amount of glitter. When activated, it ejects glitter in every directions. You could say it’s harmless, as it’s just glitter. But then again, glitter has a way of staying with you for the rest of your life — turning up at the least expected times. It certainly leaves an emotional impression.
Activation is quite clever; the fake package sits on the porch until an accelerometer detects movement. At that point, GPS checks to see if the package has traveled outside a geo-fence around [Mark]’s house. A signal is then sent to the four smartphones to start recording — yes, that’s right, there are 4 phones inside, one on each side to capture the reaction of the thief.
How can [Mark] be so confident that he’ll be able to recover the four phones and their footage? That’s answered by GPS tracking and a can of fart spray actuated by a 3D printed cam and DC motor, ensuring the thief won’t want this package around for long. This actuator and the glitter motor are controlled by a custom PCB, which also triggers the phones to start recording through their headphone jacks and detects the opening of the package with some microswitches. This is truly a masterpiece that outsmarts the package thieves in a way that leaves an impression while still being playful.
(Editor’s Note 2: On 12/20/18 it was announced that two of the five thieves shown in the originally video were staged, apparently without [Mark Rober’s] knowledge. Here is his statement on the matter.)
Jeremy Hong knows a secret or two about things you shouldn’t do with radio frequency (RF), but he’s not sharing.
That seems an odd foundation upon which to build one’s 2018 Hackaday Superconference talk, but it’s for good reason. Jeremy knows how to do things like build GPS and radar jammers, which are federal crimes. Even he hasn’t put his knowledge to practical use, having built only devices that never actually emitted any RF.
If you mention a clock that receives its time via radio, most people will think of one taking a long wave signal from a station such as WWVB, MSF, or DCF77. A more recent trend however has been for clocks that set themselves from orbiting navigation satellites, and an example comes to us from [KK99]. It’s a relatively simple hardware build in that it is simply an Arduino Nano, GPS module, and e-ink display module wired together, but it provides an interesting exercise in running through the code required for a GPS clock.
