Curated

76 Articles

Hackaday’s finest original content articles curated by the Hackaday editors

A Modern Take On An Old Language

August 16, 2024 by 44 Comments

Some old computer languages are destined to never die. They do, however, evolve. For example, Fortran, among the oldest of computer languages, still has adherents, not to mention a ton of legacy code to maintain. But it doesn’t force you to pretend you are using punched cards anymore. In the 1970s, if you wanted to crunch numbers, Fortran was a good choice. But there was another very peculiar language: APL. Turns out, APL is alive and well and has a thriving community that still uses it.

APL has a lot going for it if you are crunching serious numbers. The main data type is a multidimensional array. In fact, you could argue that a lot of “modern” ideas like a REPL, list types, and even functional programming entered the mainstream through APL. But it did have one strange thing that made it difficult to use and learn.

[Kenneth E. Iverson] was at Harvard in 1957 and started working out a mathematical notation for dealing with arrays. By 1960, he’d moved to IBM and a few years later wrote a book entitled “A Programming Language.” That’s where the name comes from — it is actually an acronym for the book’s title. Being a mathematician, [Iverson] used symbols instead of words. For example, to create an array with the numbers 1 to 5 in it and then print it, you’d write:

⎕←⍳5

Since modern APL has a REPL (read-eval-print loop), you could remove the box and the arrow today.

What Key Was That?

Wait. Where are all those keys on your keyboard? Ah, you’ve discovered the one strange thing. In 1963, CRTs were not very common. While punched cards were king, IBM also had a number of Selectric terminals. These were essentially computer-controlled typewriters that had type balls instead of bars that were easy to replace.

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Australia’s Controlled Loads Are In Hot Water

August 15, 2024 by 125 Comments

Australian grids have long run a two-tiered pricing scheme for electricity. In many jurisdictions, regular electricity was charged at a certain rate. Meanwhile, you could get cheaper electricity for certain applications if your home was set up with a “controlled load.” Typically, this involved high energy equipment like pool heaters or hot water heaters.

This scheme has long allowed Australians to save money while keeping their water piping-hot at the same time. However, the electrical grid has changed significantly in the last decade. These controlled loads are starting to look increasingly out of step with what the grid and the consumer needs. What is to be done?

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Laser Cutters: Where’s The Point?

August 14, 2024 by 31 Comments

It is funny how when you first start doing something, you have so many misconceptions that you have to discard. When you look back on it, it always seems like you should have known better. That was the case when I first got a low-end laser cutter. When you want to cut or engrave something, it has to be in just the right spot. It is like hanging a picture. You can get really close, but if it is off just a little bit, people will notice.

The big commercial units I’ve been around all had cameras that were in a fixed position and were calibrated. So the software didn’t show you a representation of the bed. It showed you the bed. The real bed plus whatever was on it. Getting things lined up was simply a matter of dragging everything around until it looked right on the screen.

Today, some cheap laser cutters have cameras, and you can probably add one to those that don’t. But you still don’t need it. My Ourtur Laser Master 3 has nothing fancy, and while I didn’t always tackle it the best way, my current method works well enough. In addition, I recently got a chance to try an XTool S1. It isn’t that cheap, but it doesn’t have a camera. Interestingly, though, there are two different ways of laying things out that also work. However, you can still do it the old-fashioned way, too. Continue reading “Laser Cutters: Where’s The Point?” →

The Long, Slow Demise Of DVD-RAM

August 13, 2024 by 35 Comments

While CDs were still fighting for market share against cassettes, and gaming consoles were just starting to switch over to CD from cartridge storage, optical media companies were already thinking ahead. Only two years after the introduction of the original PlayStation, the DVD Forum had introduced the DVD-RAM standard: 2.58 GB per side of a disc in a protective caddy. The killer feature? Essentially unlimited re-writeability. In a DVD drive that supports DVD-RAM, they act more like removable hard drive platters. You can even see hard sectors etched into the media at the time of manufacture, giving DVD-RAM its very recognizable pattern.

At the time, floppy drives were still popular, and CD-ROM drives were increasingly available pre-installed in new computers. Having what amounted to a hard drive platter with a total of 5 GB per disc should have been a killer feature for consumers. Magneto-optical drives were still very expensive, and by 1998 were only 1.3 GB in size. DVD-RAM had the same verify-after-write data integrity feature that magneto-optical drives were known for, but with larger capacity, and after the introduction of 4.7 GB size discs, no caddy was required.

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The First Fitbit: Engineering And Industrial Design Lessons

August 9, 2024 by 7 Comments

It could happen to anyone of us: suddenly you got this inkling of an idea for a product that you think might just be pretty useful or even cool. Some of us then go on to develop a prototype and manage to get enough seed funding to begin the long and arduous journey to turn a sloppy prototype into a sleek, mass-produced product. This is basically the story of how the Fitbit came to be, with a pretty in-depth article by [Tekla S. Perry] in IEEE Spectrum covering the development process and the countless lessons learned along the way.

Of note was that this idea for an accelerometer-based activity tracker was not new in 2006, as a range of products already existed, from 1960s mechanical pedometers to 1990s medical sensors and the shoe-based Nike+ step tracker that used Apple’s iPod with a receiver. Where this idea for the Fitbit was new was that it’d target a wide audience with a small, convenient (and affordable) device. That also set them up for a major nightmare as the two inventors were plunged into the wonderfully terrifying world of industrial design and hardware development.

One thing that helped a lot was outsourcing what they could to skilled people and having solid seed funding. This left just many hardware decisions to make it as small as possible, as well as waterproof and low-power. The use of the ANT protocol instead of Bluetooth saved a lot of battery, but meant a base station was needed to connect to a PC. Making things waterproof required ultrasonic welding, but lack of antenna testing meant that a closed case had a massively reduced signal strength until a foam shim added some space. The external reset pin on the Fitbit for the base station had a low voltage on it all the time, which led to corrosion issues, and so on.

While much of this was standard development and testing  fun, the real challenge was in interpreting the data from the accelerometer. After all, what does a footstep look like to an accelerometer, and when is it just a pothole while travelling by car? Developing a good algorithm here took gathering a lot of real-world data using prototype hardware, which needed tweaking when later Fitbits moved from being clipped-on to being worn on the wrist. These days Fitbit is hardly the only game in town for fitness trackers, but you can definitely blame them for laying much of the groundwork for the countless options today.

The First Real Sputnik

August 7, 2024 by 17 Comments

Americans certainly remember Sputnik. At a time when the world was larger and scarier, the Soviets had a metal basketball flying over the United States and the rest of the world. It made people nervous, but it was also a tremendous scientific achievement. However, it wasn’t the plan to use it as the first orbiter, as [Scott Manley] explains in a recent video that you can see below.

The original design would become Sputnik 3, which, as [Scott] puts it, was the first Soviet satellite that “didn’t suck.” The first one was essentially a stunt, and the second one had an animal payload and thermal problems that killed the canine occupant, [Laika].

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I2C For Hackers: The Basics

August 7, 2024 by 51 Comments

You only really need two data wires to transfer a ton of data. Standards like UART, USB2, I2C, SPI, PS/2, CAN, RS232, SWD (an interface to program MCUs), RS485, DMX, and many others, all are a testament to that. In particular, I2C is such a powerful standard, it’s nigh omnipresent – if you were to somehow develop an allergy to I2C, you would die.

Chances are, whatever device you’re using right now, there’s multiple I2C buses actively involved in you reading this article. Your phone’s touchscreen is likely to use I2C, so is your laptop touchpad, most display standards use I2C, and power management chips are connected over I2C more often than not, so you’re covered even if you’re reading this on a Raspberry Pi! Basically everything “smart” has an I2C port, and if it doesn’t, you can likely imitate it with just two GPIOs.

If you’re building a cool board with a MCU, you should likely plan for having an I2C interface exposed. With it, you can add an LCD screen with a respectable resolution or a LED matrix, or a GPS module, a full-sized keyboard or a touchpad, a gesture sensor, or a 9 degree of freedom IMU – Inertial Measurement Unit, like a accelerometer+compass+gyroscope combination. A small I2C chip can help you get more GPIOs for your MCU or CPU, or a multi-channel motor driver, or a thermal camera, or a heap of flash memory; if you’re adding some sort of cool chip onto your board, it likely has an I2C interface to let you fine-tune its fancy bits.

As usual, you might have heard of I2C, and we sure keep talking about it on Hackaday! There’s a good few long-form articles about it too, both general summaries and cool tech highlights; this article is here to fill into some gaps and make implicit knowledge explicit, making sure you’re not missing out on everything that I2C offers and requires you to know!

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