Where Do You Connect The Shield?

September 13, 2024 by Arya Voronova 7 Comments

When it comes to polarizing and confusing questions in electronics, wiring up shields is on the top-10 list when sorted by popularity. It’s a question most of us need to figure out at some point – when you place a USB socket symbol on your schematic, where do you wire up the SHIELD and MP pins?

Once you look it up, you will find Eevblog forum threads with dozens of conflicting replies, Stackexchange posts with seven different responses plus a few downvoted ones, none of them accepted, and if you try to consult the literature, the answer will invariably be “it depends”.

I’m not a connector-ground expert, I just do a fair bit of both reading and hacking. Still, I’ve been trying to figure out this debate, for a couple years now, re-reading the forum posts each time I started a new schematic with a yet-unfamiliar connector. Now, of course, coming to this question with my own bias, here’s a summary you can fall back on.

Consumer Ports

Putting HDMI on your board? First of all, good luck. Then, consider – do you have a reason to avoid connecting the shield? If not, certainly connect the shield to ground, use jumpers if that’s what makes you comfortable, though there’s a good argument that you should just connect directly, too. The reason is simple: a fair few HDMI cables omit GND pin connections, fully relying on the shield for return currents. When your HDMI connection misfires, you don’t want to be debugging your HDMI transmitter settings when the actual No Signal problem, as unintuitive as it sounds, will be simply your shield not being grounded – like BeagleBone and Odroid didn’t in the early days. By the way, is a DVI-D to HDMI adapter not working for you? Well, it might just be that it’s built in a cheap way and doesn’t connect the shields of the two sockets together – which is fixable.

Continue reading “Where Do You Connect The Shield?” →

Review: IFixit’s FixHub May Be The Last Soldering Iron You Ever Buy

September 12, 2024 by Tom Nardi 81 Comments

Like many people who solder regularly, I decided years ago to upgrade from a basic iron and invest in a soldering station. My RadioShack digital station has served me well for the better part of 20 years. It heats up fast, tips are readily available, and it’s a breeze to dial in whatever temperature I need. It’s older than both of my children, has moved with me to three different homes, and has outlived two cars and one marriage (so far, anyway).

When I got this, Hackaday still used B&W pictures.

As such, when the new breed of “smart” USB-C soldering irons started hitting the scene, I didn’t find them terribly compelling. Oh sure, I bought a Pinecil. But that’s because I’m an unrepentant open source zealot and love the idea that there’s a soldering iron running a community developed firmware. In practice though, I only used the thing a few times, and even then it was because I needed something portable. Using it at home on the workbench? It just never felt up to the task of daily use.

So when iFixit got in contact a couple weeks back and said they had a prototype USB-C soldering iron they wanted me to take a look at, I was skeptical to say the least. But then I started reading over the documentation they sent over, and couldn’t deny that they had some interesting ideas. For one, it was something of a hybrid iron. It was portable when you needed it to be, yet offered the flexibility and power of a station when you were at the bench.

Even better, they were planning on putting their money where their mouth is. The hardware was designed with repairability in mind at every step. Not only was it modular and easy to open up, but the company would be providing full schematics, teardown guides, and spare parts.

Alright, fine. Now you’ve got my attention.

Continue reading “Review: IFixit’s FixHub May Be The Last Soldering Iron You Ever Buy” →

Lithium-Ion Battery Hotswapping, Polarity, Holders

September 11, 2024 by Arya Voronova 26 Comments

Everyone loves, and should respect, lithium-ion batteries. They pack a ton of power and can make our projects work better. I’ve gathered a number of tips and tricks about using them over the years, based on my own hacking and also lessons I’ve learned from others.

This installment includes a grab-bag of LiIon tricks that will help you supercharge your battery use, avoid some mistakes, and make your circuits even safer. Plus, I have a wonderful project that I just have to share.

Hot-swapping Cells

When your device runs out of juice, you might not always want to chain yourself to a wall charger. Wouldn’t it be cool if you could just hot-swap cells? Indeed it is, I’ve been doing it for years, it’s dead simple to support, but you can also do it wrong. Let me show you how to do it right!

Recently, a new handheld has hit the hacker markets – the Hackberry Pi. With a Blackberry keyboard and a colour screen, it’s a pretty standard entry into the trend of handheld Pi Zero-backed computers with Blackberry keyboards. It’s not open-source and the author does not plan to open-source its hardware, so I want to make it absolutely clear I don’t consider it hacker-friendly or worth promoting. It did publish schematics, though, and these helped me find a dangerous mistake that the first revision made when trying to implement LiIon battery hot-swap. Continue reading “Lithium-Ion Battery Hotswapping, Polarity, Holders” →

A Look At The Small Web, Part 1

September 10, 2024 by Jenny List 59 Comments

In the early 1990s I was privileged enough to be immersed in the world of technology during the exciting period that gave birth to the World Wide Web, and I can honestly say I managed to completely miss those first stirrings of the information revolution in favour of CD-ROMs, a piece of technology which definitely didn’t have a future. I’ve written in the past about that experience and what it taught me about confusing the medium with the message, but today I’m returning to that period in search of something else. How can we regain some of the things that made that early Web good?

We All Know What’s Wrong With The Web…

It’s likely most Hackaday readers could recite a list of problems with the web as it exists here in 2024. Cory Doctrow coined a word for it, enshitification, referring to the shift of web users from being the consumers of online services to the product of those services, squeezed by a few Internet monopolies. A few massive corporations control so much of our online experience from the server to the browser, to the extent that for so many people there is very little the touch outside those confines. Continue reading “A Look At The Small Web, Part 1” →

Reinforcing Plastic Polymers With Cellulose And Other Natural Fibers

September 9, 2024 by Maya Posch 10 Comments

While plastics are very useful on their own, they can be much stronger when reinforced and mixed with a range of fibers. Not surprisingly, this includes the thermoplastic polymers which are commonly used with FDM 3D printing, such as polylactic acid (PLA) and polyamide (PA, also known as nylon). Although the most well-known fibers used for this purpose are probably glass fiber (GF) and carbon fiber (CF), these come with a range of issues, including their high abrasiveness when printing and potential carcinogenic properties in the case of carbon fiber.

So what other reinforcing fiber options are there? As it turns out, cellulose is one of these, along with basalt. The former has received a lot of attention currently, as the addition of cellulose and similar elements to thermopolymers such as PLA can create so-called biocomposites that create plastics without the brittleness of PLA, while also being made fully out of plant-based materials.

Regardless of the chosen composite, the goal is to enhance the properties of the base polymer matrix with the reinforcement material. Is cellulose the best material here?

Continue reading “Reinforcing Plastic Polymers With Cellulose And Other Natural Fibers” →

Ask Hackaday, What’s Next?

September 6, 2024 by Jenny List 39 Comments

Writing for Hackaday involves drinking from the firehose of tech news, and seeing the latest and greatest of new projects and happenings in the world of hardware. But sometimes you sit back in a reflective mood, and ask yourself: didn’t this all used to be more exciting? If you too have done that, perhaps it’s worth considering how our world of hardware hacking is fueled, and what makes stuff new and interesting.

Hardware projects are like startup fads

An AliExpress page of Nixie clock kits — When AliExpress has hundreds of kits for them, Nixie clocks are a mature project sector, by any measure.

Hardware projects are like startup fads, they follow the hype cycle. Take Nixie clocks for instance, they’re cool as heck, but here in 2024 there’s not so much that’s exciting about them. If you made one in 2010 you were the talk of the town, in 2015 everyone wanted one, but perhaps by 2020 yours was simply Yet Another Nixie Clock. Now you can buy any number of Nixie clock kits on Ali, and their shine has definitely worn off. Do you ever have the feeling that the supply of genuinely new stuff is drying up, and it’s all getting a bit samey? Perhaps it’s time to explore this topic.

I have a theory that hardware hacking goes in epochs, each one driven by a new technology. If you think about it, the Arduino was an epoch-defining moment in a readily available and easy to use microcontroller board; they may be merely a part and hugely superseded here in 2024 but back in 2008 they were nothing short of a revolution if you’d previously has a BASIC Stamp. The projects which an Arduino enabled produced a huge burst of creativity from drones to 3D printers to toaster oven reflow and many, many, more, and it’s fair to say that Hackaday owes its early-day success in no small part to that little board from Italy. To think of more examples, the advent of affordable 3D printers around the same period as the Arduino, the Raspberry Pi, and the arrival of affordable PCB manufacture from China were all similar such enabling moments. A favourite of mine are the Espressif Wi-Fi enabled microcontrollers, which produced an explosion of cheap Internet-connected projects. Suddenly having Wi-Fi went from a big deal to built-in, and an immense breadth of new projects came from those parts. Continue reading “Ask Hackaday, What’s Next?” →

If Wood Isn’t The Biomass Answer, What Is?

September 5, 2024 by Jenny List 120 Comments

As we slowly wean ourselves away from our centuries-long love affair with fossil fuels in an attempt to reduce CO₂ emissions and combat global warming, there has been a rapid expansion across a broad range of clean energy technologies. Whether it’s a set of solar panels on your roof, a wind farm stretching across the horizon, or even a nuclear plant, it’s clear that we’ll be seeing more green power installations springing up.

One of the green power options is biomass, the burning of waste plant matter as a fuel to generate power. It releases CO₂ into the atmosphere, but its carbon neutral green credentials come from that CO₂ being re-absorbed by new plants being grown. It’s an attractive idea in infrastructure terms, because existing coal-fired plants can be converted to the new fuel. Where this is being written in the UK we have a particularly large plant doing this, when I toured Drax power station as a spotty young engineering student in the early 1990s it was our largest coal plant; now it runs on imported wood pellets.

Continue reading “If Wood Isn’t The Biomass Answer, What Is?” →