Ask Hackaday: How Much Would You Stake On An Online Retailer

November 8, 2024 by Jenny List 69 Comments

On the bench where this is being written, there’s a Mitutoyo vernier caliper. It’s the base model with a proper vernier scale, but it’s beautifully made, and it’s enjoyable to see younger hardware hackers puzzle over how to use it. It cost about thirty British pounds a few years ago, but when it comes to quality metrology instruments that’s really cheap. The sky really is the limit for those in search of ultimate accuracy and precision. We can see then why this Redditor was upset when the $400 Mitutoyo they ordered from Amazon turned out to be nothing of the sort. We can’t even call it a fake, it’s just a very cheap instrument stuffed oddly, into a genuine Mitutoyo box.

Naturally we hope they received a refund, but it does raise the question when buying from large online retailers; how much are we prepared to risk? We buy plenty of stuff from AliExpress in out community, but in that case the slight element of chance which comes with random Chinese manufacture is offset by the low prices. Meanwhile the likes of Amazon have worked hard to establish themselves as trusted brands, but is that misplaced? They are after all simply clearing houses for third party products, and evidently have little care for what’s in the box. The £30 base model caliper mentioned above is an acceptable punt, but at what point should we go to a specialist and pay more for some confidence in the product?

It’s a question worth pondering as we hit the “Buy now” button without thinking. What’s your view? Let us know in the comments. Meanwhile, we can all be caught with our online purchases.

Thanks [JohnU] for the tip.

AI Not Needed For Hackaday Projects

November 5, 2024 by Jenny List 19 Comments

It was Supercon this weekend, and Hackaday staffers made their way to Pasadena for what was by all accounts an excellent event. Now they’re all on their way home on red-eye flights and far from their benches, so spare a thought for the lonely editor holding the fort while they’ve been having fun. The supply of cool hacks for your entertainment must continue, so what’s to be done? Fortunately Hackaday writer [Anne Ogborn] has the answer, in the form of an automated Hackaday article generator.

We once had a commenter make a withering insult that one of our contributors’ writing styles looked like the work of an AI driven bot, a sentence that the writer in question treasures enough to have incorporated in their Hackaday email signature. [Anne] is a data scientist and Prolog programmer by trade so knows a bit about AI, and she has no need for such frippery. Instead she’s made a deck of cards each marked with a common theme among the work featured here, and generating new article titles is a simple case of drawing cards from the pack and assembling the resulting sentence.

The result is both amusing and we think, uncannily on the mark. Who wouldn’t want an ESP8266 powered cardboard drone? We think it will make a valuable addition to the Hackaday armoury, to be brought out on days such as the first of April, when there’s always an unexpected shortage of hacks. Video below the break.

Continue reading “AI Not Needed For Hackaday Projects” →

Flaming Power Wheels Skeleton Wins Halloween

November 5, 2024 by Jenny List 48 Comments

When the project description starts with the sentence “I use an RC remote and receiver, an esp32, high-current motor drivers, servos, an FPV camera, and a little propane”, you know that this is one which deserves a second look. And so [gearscodeandfire]’s Halloween project caught our eye. It’s a pink Power Wheels jeep driven by a skeletal rider, and the best part is that the whole thing is remote controlled down to a pan-and-tilt skull, a first-person video feed, and even real flames.

At its heart is an ESP32 with a set of motor controllers and relays to do the heavy lifting. The controller is a standard radio remote controller, and the first-person view is an analogue feed as you’d find on a drone. The skeleton is given a child-like appearance by discarding the original adult-proportioned plastic skull and replacing it with a much larger item. The thought that plastic Halloween skulls are available in a range of standard sizes and can be considered as a part in their own right is something we find amusing. The propane burner is supplied from a small cylinder via a solenoid valve, and ignited with the spark from a high-voltage transformer.

The result, we think, wins Halloween hands down. Twelve-foot skeletons are SO 2023!

The video is below the break.

Continue reading “Flaming Power Wheels Skeleton Wins Halloween” →

Humble Television Tubes Make An FM Regenerative Radio

November 4, 2024 by Jenny List 10 Comments

The regenerative radio is long-ago superseded in commercial receivers, but it remains a common project for electronics or radio enthusiasts seeking to make a simple receiver. It’s most often seen for AM band receivers or perhaps shortwave ham band ones, but it’s a circuit which also works at much higher frequencies. [Perian Marcel] has done just this, with a regenerative receiver for the FM broadcast band.

The principle of a regenerative receiver is that it takes a tuned radio frequency receiver with a wide bandwidth and poor performance, and applies feedback to the point at which the circuit is almost but not quite oscillating. This has the effect of hugely increasing the “Q”, or quality factor of the receiver, giving it much more sensitivity and a narrow bandwidth. They’re tricky to tune but they can give reasonable performance, and they will happily slope-demodulate an FM transmission.

This one uses two tubes from consumer grade TV receivers, the “P” at the start of the part number being the giveaway for a 300mA series heater chain. The RF triode-pentode isn’t a radio part at all, instead it’s a mundane TV field oscillator part pushed into service at higher frequencies, while the other triode-pentode serves as an audio amplifier. The original circuit from which this one is adapted is available online, All in all it’s a neat project, and a reminder that exotic parts aren’t always necessary at higher frequencies. The video is below the break.

Continue reading “Humble Television Tubes Make An FM Regenerative Radio” →

M.2 Makes An Unusual Microcontroller Form Factor

November 3, 2024 by Jenny List 40 Comments

When we think of an m.2 slot in our laptop or similar, it’s usually in the context of its PCI connectivity for high-speed applications such as solid state disks. It’s a connector that offers much more than that interface though, making it suitable for some unexpected add-ons. As an example [MagicWolfi] has produced an m.2 card which contains the equivalent of a Raspberry Pi Pico.

The board itself has the familiar m.2 edge connector at the bottom, and the RP2040 GPIO lines as postage-stamp indentations round the edges. On the m.2 front is uses the USB interface as well as a UART and the I²C lines, as well as some of the interfaces we’re less familiar with such as ALERT, WAKE, DISABLE1/2, LED 1/2, and VENDOR_DEFINED.

On one level this provides a handy internal microcontroller card with which you can do all the things you’d expect from a Pi Pico, but on another it provides the fascinating possibility of the Pico performing a watchdog or other function for the host device. We would be genuinely interested to hear more about the use of the m.2 slot in this way.

If you’d like to know more about m.2, we’ve taken a look at it in more depth.

Don’t Forget Your Curve Tracer

November 2, 2024 by Jenny List 4 Comments

As cheap microcontrollers have given us an impressive range of test equipment trinkets to play with, it’s easy to forget some of the old standabys. A curve tracer for example, the relatively simple circuit allowing the plotting of electronic component response curves on an oscilloscope. Lest we forget this useful device, here’s [Gary LaRocco] with a video describing one that’s so easy to build, anyone could do it.

It’s a simple enough premise, a low AC voltage comes from a mains transformer and is dropped down to the device under test through a resistor. The X and Y inputs of the ‘scope are configured to show the current and the voltage respectively, and the result is a perfect plot of the device’s IV curve. The best part is that it’s designed for in-circuit measurement, allowing it to be used for fault-finding. There’s a demonstration at the end with a variety of different parts, lest we needed any reminder as to how useful these devices can be.

The cost of one of these circuits is minimal, given that the transformer is likely to come from an old piece of consumer electronics. It’s not the first simple curve tracer we’ve seen, but we hope it will give you ideas. The video is below the break.

Continue reading “Don’t Forget Your Curve Tracer” →

Capturing Light In A Vacuum: The Magic Of Tube Video Cameras

November 1, 2024 by Jenny List 33 Comments

Cameras are a funny rabbit hole to fall down as a hacker, because we have well over a century of items to pick and choose from, a lot of which can be had for relative pennies. In my case I have more of them than I’d care to mention, mostly film cameras and 8mm movie cameras, but there are one or two that are entirely different. My first interest in electronics came through PAL televisions, so it’s hardly surprising that along the way I’ve also acquired more than one chunky old tube-based video camera. These devices are now long ago supplanted by their solid state replacements, but they retain a fascination for me as the mirror of the CRT-based TV sets I know so well. It’s time for a fascinating descent into the world of analogue video.

Electrons chasing light, chasing electrons

The zig-zag line pattern of a TV scan. — A raster scan pattern. Ian Harvey, Public domain.

The basic mode of operation behind all but some of the very earliest electronic camera tubes is that an electron gun paints its raster of electrons onto a light-sensitive target, and the current flowing through the electron beam varies in proportion to the light at each particular point on the target. This can be used to create a voltage, which when combined with the various sync pulses makes a video signal that would be understood by a monitor. The various different types of tubes have names such as Iconoscope, Emitron, or Vidicon, and while the main differences between those various types of tube lie in the combination of materials and design of their targets. Successive generations of tube made improvements to sensitivity and noise performance, first combining photoemissive layers with electron multiplying layers to amplify the video signal in much the same way as a photomultiplier tube does, and then using photoconductive targets to vary the conductivity of the target depending on the light at a particular point. Continue reading “Capturing Light In A Vacuum: The Magic Of Tube Video Cameras” →