Author: Jenny List

3248 Articles

SMD Soldering, Without The Blobs

March 30, 2024 by 23 Comments

Hand soldering of surface mount components is a bread-and-butter task for anyone working with electronics in 2024. So many devices are simply no longer available in the older through-hole formats, and it’s now normal for even the most homebrew of circuits to use a PCB. But how do you solder your parts? If like us you put a blob of solder on a pad and drop the part into it, then [Mr. SolderFix] has some advice on a way to up your game.

The blob of solder method leaves a little more solder on the part than is optimal, sometimes a bulbous lump of the stuff. Instead, he puts a bit of flux on the pad and then applies a much smaller quantity of solder on the tip of his iron, resulting in a far better joint. As you can see in the video below, the difference is significant. He starts with passives, but then shows us the technique on a crystal, noting that it’s possible to get the solder on the top of these parts if too much is used. Yes, we’ve been there. Watch the whole video, and improve your surface mount soldering technique!

He’s someone we’ve featured before here at Hackaday, most recently in lifting surface mount IC pins.

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A Telegraph Interface For The Hacker Hotel 2024 Badge

March 30, 2024 by 5 Comments

Hacker Hotel is a small Dutch hacker event that takes place, as its name suggests, in a hotel. It’s a welcome high point in the damp of a north-west-European winter, and attendees come to its setting in the wooded Veluwe region in the centre of the country from far and wide. As is the custom with such events it has an electronic badge, and this year’s one had a rather unusual interface. Instead of a keyboard for text input, it replicates a 19th century Crook and Wheatstone telegraph, replacing the five needles of the original with a diamond-shaped grid of LEDs.

At its heart is an Espressif ESP32-C6 microcontroller which provides both a processor powerhouse and the usual array of wireless connectivity. Paired with that is a much more modest CH32V003 microcontroller to handle I/O tasks, and an e-paper screen using displays salvaged from surplus German supermarket shelf labels. That interface is handled by an array of five-way switches, and in a stroke of genius there’s a small relay on board which does nothing but provide a satisfying tactile “click”. Expansion is seen to by an SAO connector, Qwiic, and a USB-C socket. The software meanwhile is a combination of a non-volatile nametag, a complex set of puzzles used in the on-site competition, and a messaging system using the C6’s 802.15.4 mesh networking. A particularly neat feature of this was a Battleships game that could be played with another badge.

While this isn’t the first Hacker Hotel badge with an e-paper display, we like this one for its novel interface, for the mesh connectivity, and for that clicky relay. We’ll definitely be using ours as a name badge for some time to come.

The Most Annoying Thing On The Internet Isn’t Really Necessary

March 29, 2024 by 31 Comments

We’re sure you’ll agree that there are many annoying things on the Web. Which of them we rate as most annoying depends on personal view, but we’re guessing that quite a few of you will join us in naming the ubiquitous cookie pop-up at the top of the list. It’s the pesky EU demanding consent for tracking cookies, we’re told, nothing to do with whoever is demanding you click through screens and screens of slider switches to turn everything off before you can view their website.

Now [Bite Code] is here to remind us that it’s not necessary. Not in America for the somewhat obvious reason that it’s not part of the EU, and perhaps surprisingly, not even in the EU itself.

The EU does have a consent requirement, but the point made in the article is that its requirements are satisfied by the Do Not Track header standard, an HTTP feature that’s been with us since 2009 but which almost nobody implemented so is now deprecated. This allowed a user to reject tracking at the browser level, making all the cookie popups irrelevant. That popups were chosen instead, the article concludes, is due to large websites preferring to make the process annoying enough that users simply click on the consent button to make it go away, making tracking much more likely. We suspect that the plethora of cookie popups also has something to do with FUD among owners of smaller websites, that somehow they don’t comply with the law if they don’t have one.

So as we’d probably all agree, the tracking cookie situation is a mess. This post is being written of Firefox which now silos cookies to only the site which delivered them, but there seems to be little for the average user stuck with either of the big browsers. Perhaps we should all hope for a bit more competition in the future.

Cookies header: Lisa Fotios, CC0.

LoRA, With No Radio

March 29, 2024 by 30 Comments

A LoRa project has traditionally required a dedicated radio module, because it’s a commercially licenced protocol. But as the way it works has been progressively reverse engineered, it’s become ever more possible to produce a LoRA radio for yourself. But what about a LoRA radio without a radio at all? [CNLohr] has managed just that, by driving a microcontroller pin and relying on one of its harmonics to provide enough RF to be received by a LoRA gateway.

The video below the break goes into the process in great detail, revealing some of the tricks. Undersampling to create intentional aliasing for example allows subharmonic peaks to be produced in unexpected places. Most of the development is performed on Espressif microcontrollers, but as the code is optimised it becomes possible to use it on much more modest silicon. The dirt cheap CH32V003 RISC-V microcontroller for example can be a LoRA transmitter able to talk to a gateway at a range of hundreds of metres with the CH32 and 2.5km with the ESP32. The code can be found in this GitHub repository.

The CH32 can’t receive of course, and it relies on barfing harmonics all over the spectrum to work. But on the other hand its total RF output is so tiny that we’re guessing a filter for the LoRA band might even make it almost legal. He’s got a little way to go before beating the record though.

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A Stirling Engine From Minimal Parts

March 28, 2024 by 5 Comments

The model Stirling engine is a staple of novelty catalogues, and we daresay that were it not for their high price there might be more than one Hackaday reader or writer who might own one. All is not lost though, because [jirka.luftner] has posted one on Instructables which eschews the fancy machined brass of the commercial models and achieves the same result with an array of salvaged parts.

The main cylinder is a former apple drops tin with a cardboard displacer, and the CD/DVD flywheel is mounted on either a 3D printed or cut out frame with the secondary cylinder cut into it. A diaphragm for the secondary cylinder is taken from a rubber glove, and the cranks come courtesy of bent wire.

A slight mystery of this design is that it appears not to have a regenerator, or heat store. This usually lies in the path between the two cylinders to improve efficiency by taking the heat from the air as it passes in-between the two, and returning it when it goes the other way. We’re guessing that on an engine this small it’s the tin itself which performs this function. Either way this is a neat little engine that shouldn’t break the bank.

If this has whetted your appetite, you’ll be pleased to hear it’s not the first Stirling engine we’ve seen made from what was lying around.

Retrotechtacular: Build Your Own Dune Buggy, 1970s Style

March 26, 2024 by 21 Comments

The custom car phenomenon is as old as the second-hand car, yet somehow the decades which stick in the mind as their heyday are the 1960s and 1970s. If you didn’t have a dune buggy or a van with outrageously flared arches and an eye-hurting paint job you were nothing in those days — or at least that’s what those of us who were too young to possess such vehicles except as posters on our bedroom walls were led to believe. Periscope Films have put up a period guide from the early 1970s on how to build your own dune buggy, and can we just say it’s got us yearning to drive something just as outrageous?

Of course, auto salvage yards aren’t bursting with Beetles as donor cars in 2024, indeed the accident-damaged model used in the film would almost certainly now be lovingly restored instead of being torn apart to make a dune buggy. We’re taken through the process of stripping and shortening the Beetle floorpan, for which we’re thankful that in 2024 we have decent quality cutting disks, and watching the welder joining thin sheet metal with a stick welder gives us some serious respect for his skills.

Perhaps the part of this video most likely to raise a smile is how it portrays building a car as easy. Anyone who has ever hacked a car to pieces will tell you that’s the easy part, and it’s the building something from the pile of rusty parts which causes so many projects to fail. But given an accident damaged Beetle and a buggy kit in 1972 would we have dug in and given it a try? Of course!

We’ve touched on the Beetle’s hackability in the past, but some of us believe that the crown of most hackable car rests elsewhere.

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A Dial Phone SIPs Asterisk

March 24, 2024 by 11 Comments

An endless source of amusement for those of advancing years can come from handing a rotary phone to a teenager and asking them to dial a number with it. It’s rare for them to be stumped by a piece of technology, after all. [Mnutt]’s 4-year-old son had no such problems when he saw rotary phones at an art exhibition, so what was a parent to do but wire the phone to an Asterisk PBX with shortcut numbers for calls to family and such essential services as a joke line, MTA status, or even a K-pop song.

It’s possible to hook up a pulse dial phone with a SLIC module and a microcontroller, but in this case, a Grandstream SIP box did the trick. These are all-in-one devices that implement a SIP client with a physical connection, and older ones will talk to pulse dialers as well as the more usual tone dialing phones. The phone in question is a vintage American model. Writing this from Europe we were surprised to find a little simpler inside than its transatlantic counterparts of the same era.

An Asterisk install on a Raspberry Pi completed the project, and thus it became a matter of software configuration. It’s a useful run-through for Asterisk dilettantes, even if you haven’t got a 4-year-old. Perhaps you have an old payphone or two!