gps

348 Articles

Vintage Console Becomes The Calculator It Appears To Be

August 25, 2019 by 9 Comments

What’s sitting on [Bob Alexander]’s desk in the video below did not start out life as the desktop calculator it appears to be. Turning it into a standalone calculator with features the original designers couldn’t imagine turned out to be an interesting project, and a trip down the retrocomputing rabbit hole.

A little explanation is in order. Sure, with its Nixie display, calculator keypad, and chunky mid-century design, the Wang 360 desktop console looks like a retro calculator. But it’s actually only a dumb terminal for a much, MUCH bigger box, called the Electronic Package, that would fit under a desk. The foot-warming part that was once connected to [Bob]’s console by a thick cable that had been unceremoniously lopped off by a previous owner. [Bob] decided to remedy the situation with modern electronics. The console turned out to have enough room for a custom PCB carrying a PIC32, some level-shifting components, power supply modules that include the high-voltage supply for the Nixies, and a GPS module because Nixies and clocks just go together. The interesting bit is the programming; [Bob] chose to emulate the original Wang methods of doing math, which include multiplication by logarithmic addition. Doing so replicates the original look and feel of the calculator down to the rapid progression of numbers across the Nixies as the logarithms are calculated using the display registers.

We normally frown on vintage gear being given modern guts, but in this case [Bob] hit just the right balance of new and old, And given that the Electronic Packages these consoles were connected to go for $1500 or more on eBay, it was a better choice than letting the console go to scrap. A similarly respectful approach was taken with this TRS80 Model 100 revival.

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Warshipping: A Free Raspberry Pi In The Mail Is Not Always A Welcome Gift

August 19, 2019 by 39 Comments

Leading edge computer security is veiled in secrecy — a world where novel attacks are sprung on those who do not yet know what they need to protect against. Once certain tactics have played out within cool kids’ circles, they are introduced to the rest of the world. An IBM red team presented what they’re calling “warshipping”: sending an adversarial network to you in a box.

Companies concerned about security have learned to protect their internet-accessible points of entry. Patrolling guards know to look for potential wardrivers parked near or repeatedly circling the grounds. But some are comparatively lax about their shipping & receiving, and they are the ideal targets for warshipping.

Bypassing internet firewalls and security perimeters, attack hardware is embedded inside a shipping box and delivered by any of the common carriers. Security guards may hassle a van bristling with antennas, but they’ll wave a FedEx truck right through! The hardware can be programmed to stay dormant through screening, waiting to probe once inside the walls.

The presentation described several ways to implement such an attack. There is nothing novel about the raw hardware – Raspberry Pi, GPS receiver, cellular modems, and such are standard fare for various projects on these pages. The creative part is the software and in how they are hidden: in packing material and in innocuous looking plush toys. Or for persistence, they can be hidden in a wall mounted plaque alongside some discreet photovoltaic panels. (Editor’s note: What? No Great Seals?)

With this particular technique out in the open, we’re sure others are already in use and will be disclosed some years down the line. In the meantime, we can focus our efforts on more benign applications of similar technology, whether it is spying on our cat or finding the nearest fast food joint. The hardware is evolving as well: a Raspberry Pi actually seems rather heavyweight for this, how about a compact PCB with both an ESP32 and a cellular modem?

Via Ars Technica.

3D Printing Makes Modular Payload For Model Rocket

August 9, 2019 by 2 Comments

Putting payloads into model rockets can be more complex than simply shoving stuff into an open spot, so [concretedog] put some work into making a modular payload tube for his current rocket. The nose cone for his rocket is quite large, so he opted to give it a secure payload area that doesn’t compromise or interfere with any of the structural or operational bits such as the parachute.

The payload container is a hollow tube with a 3D printed threaded adaptor attached to one end. Payload goes into the tube, and the tube inserts into a hole in the bulkhead, screwing down securely. The result is an easy way to send up something like a GPS tracker, possibly with a LoRa module attached to it. That combination is a popular one with high-altitude balloons, which, like rockets, also require people to retrieve them after not-entirely-predictable landings. LoRa wireless communications have very long range, but that doesn’t help if there’s an obstruction like a hill between you and the transmitter. In those cases, a simple LoRa repeater attached to a kite, long pole, or drone can save the day.

We’ve seen [concretedog]’s work before, when he designed stackable PCBs intended to easily fit inside model rocket bodies, allowing for easy integration of microcontroller-driven functions like delayed ignitions or altimeter triggers. Better development tools, hardware, and 3D printing has really helped make smarter rocketry more accessible to hobbyists.

Inside The Mysterious Global Navigation Outage You Probably Didn’t Notice

July 19, 2019 by 19 Comments

The entire world has come to depend on satellite navigation systems in the forty or so years since the first Global Positioning System satellites took to orbit. Modern economies have been built on the presumption that people and assets can be located to within a meter or better anywhere on, above, or even slightly under the surface of the planet. For years, GPS was the only way to do that, but billions have been sunk into fielding other global navigation systems, achieving a measure of independence from GPS and to putting in place some badly needed redundancy in case of outages, like that suffered by the European Union’s Galileo system recently.

The problem with Galileo, the high-accuracy public access location system that’s optimized for higher latitudes, seems to be resolved as of this writing. The EU has been tight-lipped about the outage, however, leaving investigation into its root cause to a few clever hackers armed with SDRs and comprehensive knowledge of exactly how a constellation of satellites can use the principles of both general and special relativity to point you to your nearest Starbucks.

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Accurate Time On Your Pi, The Extreme Way

June 26, 2019 by 27 Comments

The Raspberry Pi is an extremely versatile little computer, but even its most ardent fans would acknowledge that there are some areas in which its hardware is slightly lacking. One of these is in the field of timing, the little board has no real-time clock. Users must rely on the on-board crystal oscillator, which is good enough as a microprocessor clock but subject to the vagaries of temperature as it is, not so much as a long-term timepiece.

[Manawyrm] has tackled this problem in a rather unusual way, by dispensing entirely with the crystal oscillator on an older Pi model and instead using a clock derived from a GPS source. The source she’s used is a Leo Bodnar mini precision GPS reference clock, which includes a low-jitter synthesiser that can be set to the Pi’s 19.2 MHz required clock. Unexpectedly this also required a simple LC low-pass filter which was made on a sheet of PCB material, because the Pi at first appeared to be picking up a harmonic frequency. The Pi now has a clock that’s sufficiently stable for tasks such as WSPR transmission without constant referral to NTP or other timing sources to keep it on-track.

It’s a short write-up, but it brings with it a further link to a discussion of different time synchronisation techniques on a Pi including using a kernel module to synchronise with the more common GPS-derived 1PPS signal. We’ve not seen anyone else do this particular mod to a Pi before, but conversely we’ve seen a Pi provide an RF time reference to something else.

GPS And ADS-B Problems Cause Cancelled Flights

June 9, 2019 by 80 Comments

Something strange has been going on in the friendly skies over the last day or so. Flights are being canceled. Aircraft are grounded. Passengers are understandably upset. The core of the issue is GPS and ADS-B systems. The ADS-B system depends on GPS data to function properly, but over this weekend a problem with the quality of the GPS data has disrupted normal ADS-B features on some planes, leading to the cancellations.

What is ADS-B and Why Is It Having Trouble?

Automatic Dependent Surveillance-Broadcast (ADS-B) is a communication system used in aircraft worldwide. Planes transmit location, speed, flight number, and other information on 1090 MHz. This data is picked up by ground stations and eventually displayed on air traffic controller screens. Aircraft also receive this data from each other as part of the Traffic Collision Avoidance System (TCAS).

ADS-B isn’t a complex or encrypted signal. In fact, anyone with a cheap RTL-SDR can receive the signal. Aviation buffs know how cool it is to see a map of all the aircraft flying above your house. Plenty of hackers have worked on these systems, and we’ve covered that here on Hackaday. In the USA, the FAA will effectively require all aircraft to carry ADS-B transponders by January 1st, 2020. So as you can imagine, most aircraft already have the systems installed.

The ADS-B system in a plane needs to get position data before it can transmit. These days, that data comes from a global satellite navigation system. In the USA, that means GPS. GPS is currently having some problems though. This is where Receiver autonomous integrity monitoring (RAIM) comes in. Safety-critical GPS systems (those in planes and ships) cross-check their current position. If GPS is sending degraded or incorrect data, it is sent to the FAA who displays it on their website. The non-precision approach current outage map is showing degraded service all over the US Eastern seaboard, as well as the North. The cause of this signal degradation is currently unknown.

What Hardware is Affected?

GPS isn’t down though — you can walk outside with your cell phone to verify that. However, it is degraded. How a plane’s GPS system reacts to that depends on the software built into the GPS receiver. If the system fails, the pilots will have to rely on older systems like VOR to navigate. But ADS-B will have even more problems. An aircraft ADS-B system needs position data to operate.  If you can’t transmit your position information, air traffic controllers need to rely on old fashioned radar to determine position. All of this adds up to a safety of flight problem, which means grounding the aircraft.

Digging through canceled flight lists, one can glean which aircraft are having issues. From the early reports, it seems like Bombardier CRJ 700 and 900 have problems. Folks on Airliners.net are speculating that any aircraft with Rockwell Collins flight management systems are having problems.

This is not a small issue, there are hundreds or thousands of canceled flights. The FAA set up a teleconference to assess the issue. Since then, the FAA has issued a blanket waiver to all affected flights. They can fly, but only up to 28,000 feet.

This is a developing story, and we’ll be keeping an eye on it. Seeing how the industry handles major problems is always educational, and there will be much to learn in the coming days.

Improving A Cheap Frequency Counter With GPS

May 23, 2019 by 10 Comments

Frequency counters are useful tools for anyone that finds themselves regularly working with time-variant signals. There are a huge range available, from cheap eBay specials to expensive lab-grade hardware. [itakeyourphoto] had a counter on the lower end of the cost spectrum, and decided to make some improvements with the help of GPS (Youtube link, embedded below).

The fundamental weakness of a cheap frequency counter is usually the internal reference against which all other signals are measured. The more accurate this is, the more accurate the counter will be. [itakeyourphoto] determined that a great way to generate a reasonably good reference frequency was by using a uBlox GPS module. Once locked on to satellites, it can use a numerically controlled oscillator to output any frequency up to 15MHz with good accuracy.

The cheap frequency counter in question used a 13 MHz internal reference, so the uBlox module was programmed to match this. [itakeyourphoto] reports that it compares favorably to his higher-end GPS-disciplined oscillators, displaying very little drift or other aberrations.

We see plenty of clocks using GPS for its accurate time, but we’ve seen projects that attempt to go even further than that, too. Video after the break.

[Thanks to jafinch78 for the tip!]

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