A Slew Of AI Courses To Get Yourself Up To Speed

April 14, 2024 by 13 Comments

When there’s a new technology, there’s always a slew of people who want to educate you about it. Some want to teach you to use their tools, some want you to pay for training, and others will use free training to entice you to buy further training. Since AI is the new hot buzzword, there are plenty of free classes from reputable sources. The nice thing about a free class is that if you find it isn’t doing it for you, there’s no penalty to just quit.

We noticed NVIDIA — one of the companies that has most profited from the AI boom — has some courses (not all free, though). Generative AI Explained, and Augment your LLM Using Retrieval Augmented Generation caught our eye. There’s also Building a Brain in 10 Minutes, and Introduction to Physics-informed Machine Learning with Modulus. These are all quite short, though.

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Logic analyzer capture, showing the rails constantly oscillating at a high rate

When Your Level Shifter Is Too Smart To Function

April 13, 2024 by 9 Comments

By now, 3.3V has become a comfortable and common logic level for basically anything you might be hacking. However, sometimes, you still need to interface your GPIOs with devices that are 5 V, 1.8 V, or something even less common like 2.5 V. At this point, you might stumble upon autosensing level shifters, like the TXB010x series Texas Instruments produces, and decide that they’re perfect — no need to worry about pin direction or bother with pullups. Just wire up your GPIOs and the two voltage rails you’re good to go. [Joshua0] warns us, however, that not everything is hunky dory in the automagic shifting world.

During board bring-up and multimeter probing, he found that the 1.8 V-shifted RESET signal went down to 1.0V — and its 3.3 V counterpart stayed at 2.6V. Was it a current fight between GPIOs? A faulty connection? Voltage rail instability? It got more confusing as the debugging session uncovered the shifting operating normally as soon as the test points involved were probed with the multimeter in a certain order. After re-reading the datasheet and spotting a note about reflection sensitivity, [Joshua0] realized he should try and probe the signals with a high-speed logic analyzer instead.

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M17 Digital Communications Go From Strength To Strength

April 13, 2024 by 6 Comments

The world of amateur radio is like many other fields in that there has been a move underway from analogue to digital modes. In fact, amateur radio has often led the way in digital innovation.  There’s a snag, though: many of the digital speech modes are proprietary. To address this along comes the M17 project, an effort to create an open digital communication protocol for radio amateurs. We’ve looked at them more than once in the past few years, and as they’ve come up with several pieces of new hardware it’s time for another peek.

First up is the Remote Radio Unit, described as “a comprehensive, UHF FM/M17 “repeater in a box,” optimally designed for close antenna placement, enhancing signal strength and reliability.” The repeater forms the “other half” of the UHF handheld radio chain and will be crucial to the uptake of the protocol.

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PicoNtrol Brings Modern Controllers To Atari 2600

April 13, 2024 by 11 Comments

While there’s an argument to be made that retro games should be experienced with whatever input device they were designed around, there’s no debating that modern game controllers are a lot more ergonomic and enjoyable to use than some of those early 8-bit entries.

Now, thanks to the PicoNtrol project from [Reogen], you can use the latest Xbox and PlayStation controllers with the Atari 2600 via Bluetooth. Looking a bit farther down the road the project is aiming to support the Nintendo Entertainment System, and there’s work being done to bring the Switch Pro Controller into the fold as well.

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Who’s Afraid Of A CRT?

April 13, 2024 by 25 Comments

Older consumer electronic devices follow a desirability curve in which after they fall from favour they can’t be given away. But as they become rarer, they reach a point at which everyone wants them. Then, they can’t be had for love nor money. CRT TVs are now in the first stage, they’re bulky and lower-definition than modern sets, and thus thrift stores and dumpsters still have them in reasonable numbers. To retrogamers and other enthusiasts, this can be a bonanza, and when he saw a high-end late-model JVC on the sidewalk [Chris Person] wasted no time in snapping it up. It worked, but there were a few picture issues, so he set about fixing it.

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Delays And Timers In LTSpice (no 555)

April 13, 2024 by 2 Comments

If you need a precise time, you could use a microcontroller. Of course, then all your friends will say “Could have done that with a 555!” But the 555 isn’t magic — it uses a capacitor and a comparator in different configurations to work. Want to understand what’s going on inside? [Mano Arrostita] has a video about simulating delay and timer circuits in LTSpice.

The video isn’t specifically about the 555, but it does show how the basic circuits inside a timer chip work. The idea is simple: a capacitor will charge through a resistor with an exponential curve. If you prefer, you can charge with a constant current source and get a nice linear charge.

You can watch the voltage as the capacitor charges and when it reaches a certain point, you know a certain amount of time has passed. The discharge works the same way, of course.

We like examining circuits for learning with a simulator, either LTSpice or something like Falstad. It is easier than breadboarding and encourages making changes that would be more difficult on a real breadboard. If you want a refresher on LTSpice or current sources, you can kill two birds with one stone.

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A Bend Sensor Developed With 3D Printer Filament

April 13, 2024 by 6 Comments

PhD students spend their time pursuing whatever general paths their supervisor has given them, and if they are lucky, it yields enough solid data to finally write a thesis without tearing their hair out. Sometimes along the way they result in discoveries with immediate application outside academia, and so it was for [Paul Bupe Jr.], whose work resulted in a rather elegant and simple bend sensor.

The original research came when shining light along flexible media, including a piece of transparent 3D printer filament. He noticed that when the filament was bent at a point that it was covered by a piece of electrical tape there was a reduction in transmission, and from this he was able to repeat the effect with a piece of pipe over a narrow air gap in the medium.

Putting these at regular intervals and measuring the transmission for light sent along it, he could then detect a bend. Take three filaments with  the air-gap-pipe sensors spaced to form a Gray code, and he could digitally read the location.

He appears to be developing this discovery into a product. We’re not sure which is likely to be more stress, writing up his thesis, or surviving a small start-up, so we wish him luck.