Beyond The Basics: Exploring More Exotic Scope Trigger Modes

December 27, 2023 by 2 Comments

Last time, we looked at some powerful trigger modes found on many modern scopes, including the Rigol DHO900 series we used as an example. Those triggers were mostly digital or, at least, threshold-based. This time, we’ll look at some more advanced analog triggers as well as a powerful digital trigger that can catch setup and hold violations. You can find the Raspberry Pi code to create the test waveforms online.

In addition to software, you’ll need to add some simple components to generate the analog waveform. In particular, pin 21 of the Pi connects to  2uF capacitor through a 10K resistor. The other side of the capacitor connects to ground. In addition, pin 22 connects directly to the capacitor, bypassing the 10K resistor. This allows us to discharge the capacitor quickly. The exact values are not especially important.

Runt Triggers

A runt pulse is one that doesn’t have the same voltage magnitude as surrounding pulses. Sometimes, this is due to a bus contention, for example. Imagine if you have some square waves that go from 0 to 5V. But, every so often, one pulse doesn’t make it to 5V. Instead, it stops at 3V.

Continue reading “Beyond The Basics: Exploring More Exotic Scope Trigger Modes” →

Paged Out! Releases Long-Awaited Third Issue

December 27, 2023 by 4 Comments

We’re happy to pass along word that Paged Out! has finally released Issue #3. This online zine covers a wide array of technical topics, from software development to hardware hacking, computer security, and electronics.

It’s distributed as a PDF, and is notable for its somewhat experimental format that limits each article to a single page. The first two issues were released back in 2019, but between a global pandemic and some administrative shuffling, progress on the current release was slowed considerably.

Among the 50 articles that make up the third Paged Out! there are a number of pieces focusing on hardware, such as the serial communications “cheat sheet” from [Jay Greco], and a pair of articles covering the state-of-the-art in custom keyboards. But overall the zine does lean hard into programming topics, and is probably best suited for those with an interest in software development and infosec.

Still, the line between hardware and software is getting blurrier all the time, so we’re sure you can find something in Paged Out! that should interest you no matter which side of the fence you’re on. Here’s hoping the time between releases can be reduced a bit for Issue #4.

Liftoff! The Origin Of The Countdown

December 27, 2023 by 18 Comments

What’s the most thrilling part of rocketry? Well, the liftoff, naturally. But what about the sweet anticipation in those tense moments leading up to liftoff? In other words, the countdown. Where did it come from?

Far from being simply a dramatic device, the countdown clock serves a definite purpose — it lets the technicians and the astronauts synchronize their actions during the launch sequence. But where did the countdown  — those famed ten seconds of here we go! that seem to mark the point of no return — come from? Doesn’t it all seem a little theatrical for scientists?

It may surprise you to learn that neither technicians nor astronauts conceived of the countdown. In their book, “Lunar Landings and Rocket Fever: Rediscovering Woman in the Moon”, media scholars Tom Gunning and Katharina Loew reveal that a little-known Fritz Lang movie called Woman In the Moon both “predicted the future of rocketry” and “played an effective role in its early development”.

Continue reading “Liftoff! The Origin Of The Countdown” →

Veteran SpaceX Booster Lost Due To Rough Seas

December 27, 2023 by 44 Comments

With the notable exception of the now retired Space Shuttle orbiters, essentially every object humanity ever shot into space has been single-use only. But since December of 2015, SpaceX has been landing and refurbishing their Falcon 9 boosters, with the end goal of operating their rockets more like cargo aircraft. Today, while it might go unnoticed to those who aren’t closely following the space industry, the bulk of the company’s launches are performed with boosters that have already completed multiple flights.

This reuse campaign has been so successful these last few years that the recent announcement the company had lost B1058 (Nitter) came as quite a surprise. The 41 meter (134 foot) tall booster had just completed its 19th flight on December 23rd, and had made what appeared to be a perfect landing on the drone ship Just Read the Instructions. But sometime after the live stream ended, SpaceX says high winds and powerful waves caused the booster to topple over.

Continue reading “Veteran SpaceX Booster Lost Due To Rough Seas” →

Temperature Measurement By Wire

December 27, 2023 by 7 Comments

There’s an old joke about how to tell how tall a building is using a barometer. The funniest answer is to find the building owner and offer them a nice barometer in exchange for the information. We wonder if [DiodeGoneWild] has heard that one since his recent video details how to measure temperatures using an ohmmeter.

The idea is that wire changes its resistance based on temperature. So if you know the resistance of a lot of wire — maybe a coil — at room temperature and you can measure the resistance at temperature, it is entirely feasible to calculate the amount of temperature that would cause this rise in resistance.

Of course, there are many ways to measure resistance, too. It’s probably possible to measure parameters like operating current and estimate temperature for at least some circuits. The wire’s material also plays a part, and the online calculator lets you choose copper, aluminum, iron, or tungsten. You also need a lot of wire, a very accurate resistance measurement, or, preferably, both.

There are many ways to accurately measure resistance, of course. Then again, you can also get resistors specifically for the job.

Continue reading “Temperature Measurement By Wire” →

An RC Tank Chassis That’s Not Messing About

December 26, 2023 by 3 Comments

It’s not uncommon to see a tracked robot build on these pages, but it’s fair to say that many of them are somewhat on the small side. That was where [iforce2d] started, but the idea of making a more capable version just wouldn’t go away. Thus, he’s come back and made what looks to be a very promising, fully capable outdoor RC tank chassis, one that, within reason, we think should eventually be able to go anywhere.

For plenty of power, he’s using a pair of hoverboard motors with a chain reduction drive and in turn, a couple of shafts to the tracks. The chassis is a TIG-welded aluminium affair, while the tracks are an early incarnation with machined MDF drive wheels and a homemade tread. The suspension is a work of machined-aluminium art, though, and while there are teething troubles as he takes it for a spin, we can see plenty of potential as its deficiencies are ironed out.  Take a look at it in the video below the break.

If large-size R/C tanks are your thing, we have another for you to look at.

Continue reading “An RC Tank Chassis That’s Not Messing About” →

A RISC-V Security Key

December 26, 2023 by 6 Comments

The TKey is a RISC-V-based security key that plugs into a USB port. The device has a number of features, including a device-specific serial number, RAM scrambling, and a monitor that kills the CPU in the event of access to protected memory. There is also an FPGA that, on the end-user version, is locked down. This prevents you from changing the core features and the unique ID number for the device.

As part of the start-up code, the device calculates a hash of the application and merges it with the device ID and, potentially, a user-defined secret. If this number matches a previous calculation, it is reasonably certain that nothing has changed between the times of the calculations.

Continue reading “A RISC-V Security Key” →