Absolutely, it is essential to always run the numbers. I was once offered a sizable rebate if I accepted a non-0% car loan, but no rebate if I paid cash or had my own financing. Since their loan had no early-repayment penalty – and I demanded this in writing – I accepted their loan and paid it off upon the first statement.

My suspicion is that that sort of offer was to boost the commissions earned by the loan brokers, rather than to move cars. Or maybe both. Who knows.

0% interest offers show up fairly frequently in the USA, often as general-purpose credit cards, or for car or furniture payments, in addition to the many buy-now-pay-later services that allow financing almost anything. However, the motives for offering 0% are slightly different for each of these products.

But answering the question directly, a 0% offer is beneficial if you were already going to make the purchase and would finance it. Cheap credit makes it easy to overspend, since the payments will be “tomorrow’s problem”. For people who can afford to pay for something in full, it might still be beneficial to finance with 0% just to conserve cash on hand. But the tradeoff is having to service the debt with regular payments; missing one payment can cause the debt to resume at an exorbitant rate. It takes a decent amount of financial discipline to make a 0% offer work in your favor.

Going back to why 0% offers even exist, I’ll use furniture and cars as they’re the historic examples. Furniture is expensive, whether it’s a sectional sofa or a queen-size bed with frame and storage. There’s also a sizable markup for furniture, and competition between furniture stores is strong. Thus, to help entice people to buy furniture, sellers will offer 0%, outsourced to a loan company, with the loan subsidized by some of the profit margins.

For cars, the equation is slightly different. Sure, cars are an order of magnitude more expensive, but that also means the opportunity cost for dealers to offer 0% is correspondingly larger. Instead, 0% financing for cars is almost always subsidized by the manufacturer, not the dealers. This is a financial and business strategy that allows a car company to create more sales in a given quarter, if perhaps they need to meet certain year-end targets but are reluctant to reduce their list prices.

0% car loans induce more sales fairly quickly, but will draw on the company coffers in the years to come, because the loan company still wants their cut to be paid by someone. Consumers will usually benefit from these offers, as it’s rare for people to buy a new car outright.

It’s my opinion that if a car company has to subsidize loans to move their product, that’s a tacit admission that their product is wrongly priced or the competition is better. I would take this into consideration, although it wouldn’t necessarily carry the day when considering a purchase. After all, car payment interest is not insignificant.

Agreed. When I was fresh out of university, my first job had me debugging embedded firmware for a device which had both a PowerPC processor as well as an ARM coprocessor. I remember many evenings staring at disassembled instructions in objdump, as well as getting good at endian conversions. This PPC processor was in big-endian and the ARM was little-endian, which is typical for those processor families. We did briefly consider synthesizing one of them to match the other’s endianness, but this was deemed to be even more confusing haha

It never ceases to amaze me how prolific PowerPC/PowerISA was (still is?) in the embedded space

A quick “rule” is to see how old the word/concept is. “plaintiff” would have existed almost as long as the English legal system came into being, or probably even older to the court of Assizes pre-12th century.

Whereas firefighter as a profession might have only become a word after the establishment of fire departments by insurance companies, which I think might have been a 19th century development.

This entire series by Cathode Ray Dude is a wonderful dive into the world of PC boot sequence, for the folks interested in a touch of embedded architecture. His delivery is also on-point, given the complexity and obscurity of the topics.

From this video alone (41:15):

The way this worked was: they installed Xen hypervisor on your PC, put Hyperspace in a VM and Windows in another. Now, you either know what a VM is – and I don’t need to explain why this is terrifying – or you don’t and I need to make you understand so you never independently invent this.

And (43:59):

This is just a bad idea, ok? Virtualization belongs in data centers. Putting some poor bastard’s whole OS in a VM is a prank. It’s some Truman Show shit. It’s disassembling the coach’s car and putting it back together inside the gym. It’s not remotely worth the trouble and it probably didn’t work.

There was a ton of hairbrained theories floating around, but nobody had any definitive explanation.

Well I was new to the company and fresh out of college, so I was tasked with figuring this one out.

This checks out lol

Knowing very little about USB audio processing, but having cut my teeth in college on 8-bit 8051 processors, I knew what kind of functions tended to be slow.

I often wonder if this deep level understanding of embedded software/firmware design is still the norm in university instruction. My suspicion has been that focus moved to making use of ever-increasing SoC performance and capabilities, in the pursuit of making it Just Work™ but also proving Wirth’s Law in the process via badly optimized code.

This was an excellent read, btw.

The funny thing is that a few months ago, I bought a wand metal detector at a ham radio swap meet for $20, as a gag. Now you’re telling me that it was actually a prudent investment toward my woodworking projects??

Win!

This might be true, although I do it mostly so I can remove the earplugs and rest them around my neck if someone needs to talk to me.

The best PPE are the ones which have the fewest barriers toward using. Even the minor annoyance of having to set down untethered earplugs is best avoided, if it acts as a subconscious disincentive towards using PPE. Good safety policy adapts and accommodates this aspect of human behavior.

In a home workshop, there is no OSHA, so I’m fully responsible for my own safety protocols.

I’m nowhere even remotely comparable to a proper furniture maker, but I can tell you some pitfalls to avoid.

Don’t cut wood without eyes, ears, and face protection. The dust, noise, or fumes will get you one day or another, if without protection. I prefer earmuffs over earplugs, but if earplugs then use the ones which tether both ends together. For a face mask, I like low-profile half-masks like this one: https://www.kleintools.com/catalog/respirators/p100-half-mask-respirator-sm

Resist the urge to dive into woodworking by starting with reclaimed wood. For example, pallets are a cheap/free source of material, but it’s a hodge-podge of different varieties, all riddled with nail holes, dents, and brown stains from rusty fasteners.

That’s not to say it can’t be done, but it certainly aggravates the process if you’re just starting. I once came across a section of 2x4 recovered from a pallet, thinking that it would cut just like the pine I was used to. Instead, it wrecked two drill bits and burned a circular saw blade as well as itself. I later mailed a sample of it to the USDA Wood Identification Public Service, who informed me that it was Acer (Hard Maple). Up until then, I didn’t even know that maple came in both varieties.

It seems hard maple is tougher than nails drill bits. I’m still learning.

This sort-of happened in the USA, in a small way, during the fallout of the 2016 Wells Fargo scandal. Public sentiment of the big-name, national retail banks was awful and credit unions capitalized on the moment with advertisements contrasting profit-centric national banks with local, cooperatively-owned credit unions.

In this article where consultants to credit unions were queried a year later, there’s still some questions as to the long-term effects that may have benefited the credit unions.

I once came across a comment somewhere online that suggested – sadly without hard evidence – that the scandal may have been a win-win, since the sort of customers willing to uproot themselves from Wells Fargo tended to have smaller balances while still incurring the bookkeeping costs. And that credit unions were able to scale up to take in new customers while saving on advertising dollars.

It’s a plausible idea, that a new equilibrium would be found in the banking market. Logically extending the idea further, though, would lay bare how much additional integration credit unions would have to do with each other to achieve a truly seamless customer experience. Of course, with more young people mostly sticking to online and mobile banking, this might come in the form of backroom operational improvements, rather than a revamped brick-and-mortar experience.

Point taken. I’ve edited the title to include both measurements in inches.

It’s the curse of being engineering-minded in the USA. Much of homegym stuff here is in US customary units, but competition-inspired weightlifting equipment and anything engineering-related is in metric/SI.

Best I can do is to start with the original units (for search engine indexing), provide the conversion for people using the opposing unit system, and then try to do my work consistently within just one unit system.

Most commercial publications in the USA and UK – UPC/ISBN or not, regular or not – will often send copies of their work to the national library (ie Library of Congress). That said, those copies might not be prioritized for digital viewing. So seeing them in-person might be the only way to access them.

As for whether the publishing houses keep them, it’s probably very individualized, so who can say.

If you have a particular job focus for after you’ve graduated with your CS degree, would an internship with a related company be an option? Experience with web will be of limited use for an embedded job, and embedded experience is of limited use at a quantitative analysis company.

That’s not to say the experience is entirely pointless, since many skills across the various disciplines of CS are transferable.

When it comes to what insurance does or doesn’t cover, the best answer will come from the text of the policy itself. This is, unfortunately, very dry reading and most people – although instructed to keep a copy handy – don’t have the full text nearby. That said, because of the regulated nature of insurance in the USA, standardized forms of policies exist, and homeowner policies are no exception.

The common homeowner policies are numbered HO-1 to HO-8. HO-1 only pays out only for the ten listened “perils”, and is thus the most barren policy available. Not all HO-1 policies are verbatim identical, but the gist usually matches.

We can look at this sample text from a random HO-1 (issued by American Family Insurance). Page 5 shows that “fire or lightning” is covered, so that’s a good start.

On page 6, we find the exceptions to the coverage, so if any of these apply, the policy will not pay out. Nothing in Part A would seem to apply to a DIY LED project, unless you tell me your LEDs are radioactive. Part B also doesn’t apply, unless you’re somehow perpetuating a fraud using LEDs.

Part C reads like it could apply, because it mentions “construction”, “design, workmanship or specification”, and “maintenance”, but this section only applies to the dwelling and so refers to those things which are permanently affixed to the house. That would include things like ceiling fans and light fixtures, but wouldn’t include stuff that is attached to the walls using thumbtacks or 3M Command strips. It even says that:

However, we do cover any resulting loss to property described in Coverage A - Dwelling and Dwelling Extension not excluded or excepted in this policy.

This clause basically means the exceptions on Page 6 should be interpreted narrowly, not broadly.

The point is, in the entire policy, there isn’t a clause that requires listed equipment, and remember that this is the most bare bones policy commonly available. If such a requirement did exist, then building your own PC wouldn’t be possible, since the standards bodies do not test individual computer parts – except the PSU, because that plugs into the mains.

If a fire that damages the house does occur, the most probable causes would be due to: 1) an unlisted power supply or power brick feeding the ESP32 or the LEDs, or 2) no current limiting (eg a fuse) to cut out the power supply. Other failures like a shorted LED are unlikely to actually cause a house fire, and the insurance companies and UL know this; they’re more focused on preventing arc-faults that contribute to an estimated 50% of electrical house fires every year.

Good design and clean installation on your part, and using properly listed low-voltage power supplies, will mitigate the major fire risks, leaving just software bugs and lighting snafus for you to deal with.

As a matter of completeness, if there is an unlikely fire, be it from an LED project or from a candle falling over, the insurance company will still pay. But big or small, the claim will be recorded in the CLUE database along with the payout amount. This often reflects negatively on homeowners, so future rate increases may occur. But that varies by state. In any case, though, the insurance policy has still done its job: cover a non-intentional loss.

I would nevertheless advise you to have a look at what sort of homeowner policy your dwelling is covered under. Everything beyond HO-1 is nicer, and some even include limited claim forgiveness of some kind (for a price). Also consider talking to your insurance agent, who should be able to help interpret how the policy applies.

The other answers have touched upon the relative efficiencies between a phone charger and a desktop computer’s PSU. But I want to also mention that the comparison may be apples-to-oranges if we’re considering modern smartphones that are capable of USB Power Delivery (USB PD).

Without any version of USB PD – or its competitors like Quick Charge – the original USB specification only guaranteed 5 V and up to 500 mA. That’s 2.5 W, which was enough for USB keyboards and mice, but is pretty awful to charge a phone with. But even an early 2000s motherboard would provide this amount, required by the spec.

The USB Battery Charging (USB BC) spec brought the limit up to 1500 mA, but that’s still only 7.5 W. And even in 2024, there are still (exceedingly) cheap battery banks that don’t even support USB BC rates. Motherboards are also a mixed bag, unless they specifically say what they support.

So if you’re comparing, for example, the included phone charger with a Samsung S20 (last smartphone era that shipped a charger with the phone) is capable of 25 W charging, and so is the phone. Unless you bought the S20 Ultra, which has the same charger but the phone can support 45 W charging.

Charging the S20 Ultra on a 2004-era computer will definitely be slower than the stock charger. But charging with a 2024-era phone charger would be faster than the included charger. And then your latest-gen laptop might support 60 W charging, but because the phone maxes out at 45 W, it makes no difference.

You might think that faster and faster charging should always be less and less efficient, but it’s more complex since all charging beyond ~15 Watts will use higher voltages on the USB cable. This is allowable because even the thinnest wire insulation in a USB cable can still tolerate 9 volts or even 20 volts just fine. Higher voltage reduces current, which reduces resistive losses.

The gist is: charging is a patchwork of compatibility, so blanket statements on efficiency are few and far between.

I’ve previously spoken with PSU engineers for enterprise power supplies – specifically for 48-54v PoE equipment – who described to me that today’s switch mode power supplies (SMPS) tend to get more efficient with increasing load. The exception would be when the efficiency gains from higher loading start to become offset by the heating losses from higher input currents.

This graph for a TDK PSU shows that North American 120 VAC nominal (see here for the small difference between nominal and utilization voltages) will cause a small efficiency hit above 75% or so. And this is exactly why data centers – even in North America – will run with “high line” voltage, which is 200 VAC or higher (eg North American 208VAC delta supplies, British 240/415 wye, European 230/400 wye).

A sturdy, used, road-oriented bicycle. $200 won’t get anything too fancy, but cycling is a low-impact activity that – given the right places to bike – is meditative, improves cardio, facilitates independent exploration, and also happens to double as transportation.

I specifically say “road oriented” because I don’t want to necessarily endorse all road bikes, like the ones with carbon fibre or “Tour de France” pedigree. Likewise, mountain bikes with full-suspension sap energy away from the steady cadence ideal for a good workout, in addition to generally costing more or delivering less-than-stellar performance at low price points.

My first thought for a compact, air-blower would be the inflater for air mattresses. They’re already fairly small, have a high flow rate, and exist in forms which accept 12 VDC.

Another option is a small tank of compressed air, but that option is either heavy (steel tank) or stores air at inefficient, low pressures (plastic tank).

I suppose a third option is to rig a can of air-duster so that it blows through the whistle. That would be mechanically simple to implement a solenoid to press the valve, although there is a small environmental cost to using cans of air-duster regularly.