Robotic Fox Is Part Dog, Part Cat — Just Like The Real Thing

Foxes are cat software running on dog hardware, or so they say. And [Will Cogley] seems to have taken that to heart with this 3D-printed robotic fox, which borrows heavily from projects like Boston Dynamics Spot robodog. True, the analogy breaks down a bit when you include MIT’s Cheetah on the inspiration list, but you get the point.

Very much a work in progress — [Will]’s RoboFox lacks both a head and a tail, which he aims to add at some point — there are some interesting design elements on display here. Whereas commercial quadruped robots tend to use expensive harmonic drives for the legs, [Will] chose simpler, cheaper hobby servos for his fox’s running gear. Each leg has three of them — one each for the upper and lower leg, and another that moves the whole leg in and out relative to the body. The dual-servo design for the leg is particularly interesting — one servo drives the upper leg directly, while the other servo drives the lower leg through a gear drive and a captive bearing arrangement connected to a parallelogram linkage. The result is a quite compact assembly that still has twelve degrees of freedom, and isn’t anywhere near as “floppy” as you might expect from something driven by hobby servos.

The video below shows off the design details as well as some of the fox’s construction, including some weirdly anatomically correct poses while it’s on its back. The fox is still getting its legs — you can see a few times when the servos get the jitters, and the umbilical is clearly a hindrance for such a lightweight robot. But [Will] has made a great start here, and we’re keen to see RoboFox progress. Although we’re not sure about giving the future head animatronic eyes.

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Nissan 300zx Dash Given A New Language

You don’t have to be a car enthusiast to recognize that the 1984 Nissan 300x dash is a work of art. The graceful swoops and multisegment VFDs evoke an aesthetic that reminds us of a particular era. Rather than replace his dash with something drab and modern, [Evan] modified his dash to accept input from newer devices. Many of the sensors that feed directly into the dash are becoming harder to find as the years wear on, and rather than spoof every old device, [Evan] looked at each gauge.

Temperature and oil pressure are variable resistance sensors, and by removing half the voltage divider, it becomes a variable voltage sensor, as modern temperature sensors can output a voltage from 0 to 5. The tachometer required tracing the signal through the PCB as it expects a pulse every time a cylinder fires. By simulating cylinder pulses with a function generator, [Evan] found the filtering circuit and the microcontroller pin monitoring it. An optoisolator to protect the delicate MCU makes it easy to pipe the signal directly in.

Of course, not everything needed to be modified. A vacuum sensor provides a signal to the dash to indicate how much power the engine produces, which is pretty easy to spoof with a teensy connected to the CAN bus. All these mods are easily reversible and allow [Evan] to keep rocking the iconic dash with a more modern engine.

It’s an incredible hack that offers a view into how to trace, understand, and hack old electronics. Of course, if you’re keeping old built-in car bits, why not keep the carphone but connect it to your smartphone?

Op-Amp Challenge: Measuring PH, No Code Required

When you see a project with a digital display these days, you’ll be forgiven for assuming that there’s some kind of microcontroller behind the scenes. And while that’s often the easiest way to get a project from idea to completion, it’s rarely the most interesting way.

This digital pH meter is a great example of that “no-code” design philosophy. According to [chris], the main use for this meter will be to measure soil pH in his garden, and the reason for eschewing a microcontroller was more or less for the challenge. And quite a challenge it was. Understanding the concept of pH isn’t always easy, and many a budding chemist has fallen victim to its perils. Actually measuring pH isn’t much easier, with the need to account for a lot of variables while measuring small voltages. Adding to the challenge was the fact that pretty much every skill on display here — from using KiCad to SMD soldering — was the first time [chris] had tackled them.

To amplify the voltage from the off-the-shelf pH probe, [chris] chose an LMV358A, a high-impedance FET-input version of the venerable LM358 op-amp, so as not to load down the probe. A negative temperature coefficient (NTC) resistor in the feedback path provides temperature compensation. He also designed a split power supply to provide positive and negative rails from a single 9-volt battery. The 3.5-digit LCD display is driven by an ICL7106 integrated A/D converter and BCD driver chip. Everything went into a nice-looking plastic enclosure that’s very suitable for a portable instrument.

As of this writing, the Op-Amp Challenge has officially wrapped, and there’s a slew of last-minute entries we need to go through. Check out the competition and stay tuned to find out who the judges pick for op-amp design glory!

Bye Bye Ubuntu, Hello Manjaro. How Did We Get Here?

Last week I penned a cheesy fake relationship breakup letter to Ubuntu, my Linux distribution of choice for the last 15 years or so. It had well and truly delivered on its promise of a painless Linux desktop for most of that time, but the most recent upgrades had rendered it slow and bloated, with applications taking minutes to load and USB peripherals such as my film scanner mysteriously stopping working. I don’t have to look far to identify the point at which they adopted Snap packages as the moment when it all went wrong. I’d reached the point at which I knew our ways must part, and it was time to look for another distro.

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Apple Invent The Mechanical Watch

The Apple Watch has been on the market for long enough that its earlier iterations are now unsupported. Where some see little more than e-waste others see an opportunity, as has [NanoRobotGeek] with this mechanical watch conversion on a first-generation model.

What makes this build so special is its attention to detail. Into the Apple Watchcase has gone a Seiko movement, but it hasn’t merely been dropped into place. It uses the original Apple watch stem which is offset, so he’s had to create a linkage and a tiny pulley system to transfer the forces from one to the other. The rotor is custom-machined with am Apple logo, and the new watch face is a piece of laser-cut and heat treated zirconium. Even the watch movement itself needed a small modification to weaken the stem spring and allow the linkage to operate it.

The build is a long one with many steps, and we’re being honest when we say it would put our meager tiny machining skills to an extreme test. Sit down and take your time reading it, it really is a treat. Apple Watches may head to the tip after five years, but not this one!

See more in the video below the break, and of course long-time readers may remember we’ve considered the Apple Watch versus mechanical watches before.

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Tree Planting Festivals, Air Cannons, Self-Burying Seeds, And The Complexities Of Reforestation

At first glance the problem of how to plant trees would seem to be a straightforward one: take a seed, jam it into the soil and let nature take its course. Or alternatively do much the same with a sapling that already got a start in a nice, comfortable greenhouse before leaving it to its own devices. To the average person this is generally the point where it’s considered a ‘done deal’, but one only has to take a look at the average survival rate of saplings out in the wild to perish that thought.

Each environment offers its own set of challenges when it comes to reforestation, which can perhaps be considered ironic as many of these trees are being planted where forests used to be, albeit centuries ago in many cases. There are the easy spots, such as flat fields, with rich soil, ample rain and mild weather, to the challenging terrain of Iceland, or mountainous terrain. Here the logistics are challenging and where once rich forests flourished, the very landscape seems adamant to reject this botanic intrusion.

Further complicating matters here are the myriad of reasons why we’re looking at planting so many new trees that it has even become an internet thing, as with the 2019 ‘Team Trees’ 20 million new trees challenge. So how did we get here, why exactly are we doing all of this, and how much of these attempts do bear fruit?

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Contrary View: Chatbots Don’t Help Programmers

[Bertrand Meyer] is a decided contrarian in his views on AI and programming. In a recent Communications of the ACM blog post, he reveals that — unlike many others — he thinks AI in its current state isn’t very useful for practical programming. He was responding, in part, to another article from the ACM entitled “The End of Programming,” which, like many other articles, is claiming that, soon, no one will write software the way we do and have done for the last few decades. You can see [Matt Welsh] describe his thoughts on this in the video below. But [Bertrand] disagrees.

As we have also noted, [Bretrand] says:

“AI in its modern form, however, does not generate correct programs: it generates programs inferred from many earlier programs it has seen. These programs look correct but have no guarantee of correctness.”

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