Author: Aaron Beckendorf

194 Articles

A man's arm is shown against a mountainous backdrop. The man is wearing a black watch with an orange segment on one side.

Restoring An Altimeter Watch To Former Heights

October 10, 2026 by No comments

Finding inexpensive broken hardware for sale, buying it, and restoring it to working condition is a long-standing tradition for hackers on a limited budge. But there are some devices that are so difficult to repair that it’s usually not worth the trouble. [Vintage560] is braver than most, though, and restored an internally-damaged Casio AW-330-AT altimeter watch.

The exterior of the watch was in good condition, other than missing a readily-replaced strap, but the battery had leaked into the interior, and the watch didn’t respond in any way to new batteries. Cleaning out the guts with isopropyl alcohol, repositioning a plastic insulator, and bending some contacts back into shape at least got some segments of the LCD display to activate, while over two days of turning the crown smoothed out resistance in the analog train.

Actually getting the LCD to work properly required disassembling the watch, taking particular care with the altitude sensor. It wasn’t clear what was wrong with the LCD — the controller seemed to be working properly, and several rounds of cleaning and adjusting the ZEBRA connector didn’t make any difference.

Eventually, [Vintage560] simply purchased a new screen. On close inspection, it looked as though chemicals from the leaking battery might have dissolved some of the transparent indium tin oxide contacts on the old display. With the watch now working [Vintage560] tested it on a trip to the Alps, and with a few periodic calibrations, it remained quite accurate.

Usually when we see Casio watch hacks, the watch in question is the F91W, whether it’s being used for contactless payments, being retrofitted as a smartwatch, or going 5,000 meters underwater.

A pair of red, articulated, 3D printed hands are being used to pour water from a plastic bottle into a glass. One hand holds the bottle, and one holds the glass.

Building A Cheap, Dexterous Robot Hand

October 5, 2026 by 10 Comments

Most of the time, assuming nothing’s gone wrong with them, we take our hands so much for granted that it’s easy to forget what remarkable pieces of engineering they are: not only are they precise and sensitive enough to crack an egg or write a signature, but also strong enough to lift a weight or swing a hammer. Such performance has thus far eluded robot hands, but fortunately few tasks require it; the main challenge is dexterity, which is where [Vittorio Lumare]’s low-cost Yeah Hand could help.

The Yeah Hand is mostly 3D-printed and uses five servo motors per hand; like a human hand, it has no actuators within the fingers themselves, instead using fishing-line tendons to transfer motion from the motors. To reduce friction and keep the motors from overheating, each tendon runs through guides made from PTFE Bowden tubes; in tests, the hand ran 800 cycles of opening and closing without even getting close to overheating. The hand can lift up to eight kilograms and apply a maximum grasping force of five kg. For better grip, each finger has silicone grips along the inner surface, which let it hold smooth objects quite steady; to pick up fine objects, the thumbs have thumbnails.

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A dark optical bench is shown, with a lens in the right-hand part of the image. In front of the image, a bright blue spark appears in the air, with no equipment near it.

Upgrading A Benchtop Laser For Megawatt Power

October 4, 2026 by 7 Comments

One fascinating thing about a pulsed laser is that, though the average power may be measured in watts or milliwatts, the peak power can easily reach millions of times that. This happens even in normal operation, but as [Les’ Lab] demonstrated, adding a Q-Switch can considerably enhance the peak power.

A Q-switch is an optical attenuator; when placed in the laser cavity, it keeps the cavity from reaching resonance. This greatly limits stimulated emission, allowing energy to build up in the chamber as the gain medium becomes increasingly saturated. Eventually, at some energy level, the Q-switch suddenly stops blocking light, and the cavity lases in a very short, powerful pulse. The Q-switch doesn’t increase the energy in a laser shot, but it does release it much more quickly. In this case, [Les] used chromium-doped yttrium aluminum garnet crystals as the Q-switch and compared performance across several different crystals.

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A drone is shown, carrying underneath it a white plastic box. On the side of the box are two patch antennas. A camera extends from one end of the box, and a large GPS antenna from the other end.

Synthetic Aperture Radar Drone Gets Interferometric Imaging

September 28, 2026 by 10 Comments

It’s been more than a year since [Henrik Forstén] built the first iteration of his synthetic-aperture radar (SAR) imaging drone, and he’s certainly been productive in the meantime. Not only did he develop a much more powerful autofocus algorithm to clean up the radar images, but he also extended the software to create high-resolution interferometric images.

The main limitation of the original radar system was the GPS, which only had a resolution of about one meter; the autofocus algorithm owed much of its improved clarity to an improved estimation of the drone’s position. A simpler, though more expensive, solution was to add an RTK-capable GPS receiver. RTK (Real-Time Kinematic) receivers use a fixed ground station to constantly transmit a correction signal, letting them reach a couple centimeters of accuracy. Since the drone doesn’t actually need to know its position in real time, it can also use PPK (Post-Processing Kinematic) positioning, which compares recorded GPS signals after the flight to obtain similarly accurate positions.

[Henrik] also implemented a few other hardware improvements, including stabilizing the phase-locked loop used to generate the radar’s frequency sweep. The controller FPGA’s SD card interface had too low a bandwidth to record data in real time, so [Henrik] also implemented a simple, fast compression algorithm to speed that up. Most significantly, he also developed a program for interferometric imaging. The drone flies the same path twice at different altitudes; by comparing phase information from different passes, it’s possible to detect a target’s elevation. Normally, the radar program assumes constant elevation, making tall objects seem to lean toward the radar source; an interferogram, on the other hand, allowed [Henrik] to generate a detailed elevation map.

[Henrik] is no stranger to synthetic aperture radar; we’ve previously covered a bike-mounted iteration and a budget SAR system. If the concepts behind this are still a bit fuzzy, we’ve also covered a guide to making your own SAR setup.

A digital map is shown with a series of red waypoints making a roughly C-shaped curve. A smaller group of green waypoints stays stationary near one of the corners of the map.

Defeating Satellite Spoofing With Galileo’s Encryption

September 27, 2026 by 31 Comments

Considering how important it is for everything from navigation to keeping clocks in sync, satellite navigation systems are surprisingly vulnerable to a variety of attacks, ranging from simple jamming to more sophisticated spoofing attacks. This may be changing, though, as Galileo, Europe’s GNSS, recently demonstrated its first cryptographically-secured position fix under spoofing conditions.

Most GNSS systems, including GPS, have no verification measures to keep an adversary from transmitting a false signal at a higher power and hijacking a receiver; since GNSS signals are extremely weak by the time they reach the ground, this presents no great difficulty to a moderately well-equipped attacker.

Galileo’s Signal Authentication System (SAS) aims to fix this. The Galileo ground station pre-selects signal spreading codes, which it then encrypts with a regularly-changing secret key and publishes. A receiver which anticipates needing a verified signal can then download these encrypted codes ahead of time and store them. Galileo satellites then transmit on the E6-C pilot signal, and the receiver records the signal. After transmitting a message block, it then transmits the decryption key on a separate signal, which the receiver uses to recover the spreading codes. The receiver then correlates these spreading codes with the recorded signal to find the satellite’s pseudorange.

It’s a rather complicated system, but it works: earlier this month in Andøya, Norway, the annual Jammertest GNSS testing event took place. For one week, a wide range of organizations tested the resilience of their GNSS systems against various attacks, including jamming, delayed retransmission, and spoofing. Using five Galileo satellites, the European Space Agency was able to obtain a stable lock on their receiver even during spoofing.

In principle, this method could be extended to other GNSS systems. There’s certainly motivation to do so; very large-scale attacks have been demonstrated recently.

A laptop is shown set up on a desk next to a spectrum analyser, an SDR, and two antennas. The antennas are aimed toward assorted electronics, including headphones and a phone handset.

Reviving TEMPEST Attacks With An Injected Signal

September 20, 2026 by 3 Comments

TEMPEST attacks are often the most effective way to break air-gapped security: rather than directly accessing a computer, the attacker records the system’s unintended radio emissions and uses them to reconstruct its internal operations. This kind of attack was much more effective in the days of noisy, high-voltage CRT displays, and has gradually become less effective as electronics migrate to quieter, less powerful components. A group of researchers, however, has found that even modern electronics can become effective TEMPEST transmitters when irradiated with an RF signal.

The RF a device emits depends on the unintentional antennas in its internal structure. These are difficult to eliminate, and it’s usually not worth the effort; they’re usually small enough that they only effectively radiate at much higher frequencies than the electronics carry. The researchers’ technique, called InjectEave, radiated these electronics with a radio frequency tuned to their internal antennas, injecting that frequency into the circuit. Nonlinear electronic components, such as amplifiers, then mix the injected frequency with the internal signal, creating RF sidebands. This mixed signal then radiates out of the device and can be picked up and demodulated to recover the device’s internal signal.

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A black robotic hand is shown walking across a granite floor, using its fingers as legs.

Teaching A Robot Hand To Walk

September 19, 2026 by 25 Comments

Although it wasn’t apparently designed with this in mind, it seems particularly fortuitous that this walking robotic hand was released in time for Halloween. Designed by researchers from ETH Zurich, the slightly unsettling disembodied hand can use its fingers as legs to traverse terrain, push small objects around, and operate a keyboard.

The researchers started from commercially-available robot hand, equipped it with a battery and Raspberry Pi Zero 2 W, and developed neural net-based software to control it. The hand has twenty joints, four per finger, and the neural net iteratively outputs the next joint state, based on previous movements, the state of the hand, and the hand’s current goal. To train the net, the researchers built a simulated model, then used this for reinforcement learning; this yielded a faster walking speed than an adapted quadrupedal motion model did.

The hand was trained to move in a straight line, turn, recover from a fall, and press the keys of a keyboard (since it doesn’t have a camera, though, it can’t operate a keyboard by itself). The fall recovery is impressive to watch: in 21 out of 25 tests, it was able to right itself within twenty seconds. Due to the hand’s geometry, it drifts to the right while walking, so a constant correction needed to be applied. It did, however, manage to successfully cross fourteen varying surfaces, ranging in roughness from a rubber mat to gravel and grass. It even managed to push light objects toward goals.

The authors envision this kind of autonomous hand enabling greater freedom for a larger robot, such as a robot arm: if it needs to reach something farther away, the hand simply detaches and walks over. Regardless of the use to which they put in, such a project is already within reach of hackers; we’ve seen a few robotic hand projects here over the years.

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