Laser Cutters: Where’s The Point?

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

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

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

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

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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Hack On Self: Sense Of Time

Every now and then, a commercial product aims to help you in your life journey, in a novel way, making your life better through its presence. Over the years, I’ve been disappointed by such products far more often than I have been reassured, seeing each one of them rendered unimaginative and purposeless sometimes even despite the creator’s best intentions. The pressures of a commercial market will choke you out without remorse, metal fingers firmly placed on your neck, tightening with every move that doesn’t promise profit, and letting money cloud your project’s vision. I believe that real answers can only come from within hacker communities, and as we explore, you might come to see it the same way.

This is the tip of the iceberg of a decade-long project that I hope to demonstrate in a year or two. I’d like to start talking about that project now, since it’s pretty extensive; the overall goal is about using computers to help with human condition, on a personal level. There’s a lot of talk about computers integrating into our lives – even more if you dare consult old sci-fi, much of my inspiration.

Tackling a gigantic problem often means cutting it down into smaller chunks, though, so here’s a small sub-problem I’ve been working on, for years now, on and off: Can you use computers to modify your sense of time?

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Radio Apocalypse: HFGCS, The Backup Plan For Doomsday

To the extent that you have an opinion on something like high-frequency (HF) radio, you probably associate it with amateur radio operators, hunched over their gear late at night as they try to make contact with a random stranger across the globe to talk about the fact that they’re both doing the same thing at the same time. In a world where you can reach out to almost anyone else in an instant using flashy apps on the Internet, HF radio’s reputation as somewhat old and fuddy is well-earned.

Like the general population, modern militaries have largely switched to digital networks and satellite links, using them to coordinate and command their strategic forces on a global level. But while military nets are designed to be resilient to attack, there’s only so much damage they can absorb before becoming degraded to the point of uselessness. A backup plan makes good military sense, and the properties of radio waves between 3 MHz and 30 MHz, especially the ability to bounce off the ionosphere, make HF radio a perfect fit.

The United States Strategic Forces Command, essentially the people who “push the button” that starts a Very Bad Day™, built their backup plan around the unique properties of HF radio. Its current incarnation is called the High-Frequency Global Communications System, or HFGCS. As the hams like to say, “When all else fails, there’s radio,” and HFGCS takes advantage of that to make sure the end of the world can be conducted in an orderly fashion.

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