Making The World’s Fastest 555 Timer, Or Using A Modern IC Version

March 25, 2019 by Ted Yapo 24 Comments

If you’re not familiar with the 555 timer, suffice it to say that this versatile integrated circuit is probably the most successful ever designed, and has been used in countless designs, many of which fall very far afield from the original intent. From its introduction, the legendary 555 has found favor both with professional designers and hobbyists, and continues to be used in designs from both camps. New versions of the IC are still being cranked out, and discrete versions are built for fun, a temptation I just couldn’t resist after starting this article.

If you think all 555s are the same, think again. Today, a number of manufacturers continue to produce the 555 in the original bipolar formulation as well as lower-power CMOS. While the metal can version is no longer available, the DIP-8 is still around, as are new surface-mount packages all the way down to the chip-scale. Some vendors have also started making simplified variants to reduce the pinout. Finally, you can assemble your own version from a few parts if you need something the commercial offerings won’t do, or just want a fun weekend project. In my case, I came up with what is probably the fastest 555-alike around, although I spared little expense in doing so.

Follow along for a tour of the current state of the 555, and maybe get inspired to design something entirely new with this most versatile of parts.

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The Joy Of Properly Designed Embedded Systems

March 20, 2019 by Maya Posch 32 Comments

The ages-old dream of home automation has never been nearer to reality. Creating an Internet of Things device or even a building-wide collection of networked embedded devices is “easy” thanks to cheap building blocks like the ESP8266 WiFi-enabled microcontroller. Yet for any sizable project, it really helps to have a plan before getting started. But even more importantly, if your plan is subject to change as you work along, it is important to plan for flexibility. Practically, this is going to mean expansion headers and over-the-air (OTA) firmware upgrades are a must.

I’d like to illustrate this using a project I got involved in a few years ago, called BMaC, which grew in complexity and scope practically every month. This had us scrambling to keep up with the changes, while teaching us valuable lessons about how to save time and money by having an adaptable system architecture.

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Ask Hackaday: How Do You Draw Schematics?

March 19, 2019 by Ted Yapo 136 Comments

The lingua franca of electronic design is the schematic. I can pick up a datasheet written in Chinese (a language I do not read or speak) and usually get a half-decent idea of what the part is all about from the drawings. Unfortunately, even as my design experience has grown over the years, I haven’t quite learned to think in schematics — I need to see it on paper (or on a screen) to analyze a circuit. Whether it’s literally on the back of an envelope or sketched in the condensation on the shower stall, actually drawing a design or idea makes a huge difference in being able to understand it. And, if you’ve ever tried to explain a circuit without a schematic — in an on-line forum or over the phone, for instance — you know how difficult it is.

So, given the importance of the schematic for design and communication, you’d think choosing a tool to draw them would be an easy task. Not so. There are dozens of choices, from dedicated schematic drawing programs to using the schematic-capture facilities of simulation or PCB design tools, or even old-fashioned pencil-and-paper and its modern equivalents. Each one has its pros and cons, and may be better suited to one specific application, but you have to choose something.

So, readers of Hackaday, what do you use to convey your electronic design ideas to the world?

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The CD Is 40, The CD Is Dead

March 19, 2019 by Jenny List 127 Comments

The Compact Disc is 40 years old, and for those of us who remember its introduction it still has that sparkle of a high-tech item even as it slides into oblivion at the hands of streaming music services.

There was a time when a rainbow motif was extremely futuristic. Bill Bertram (CC BY-SA 2.5)

If we could define a moment at which consumers moved from analogue technologies to digital ones, the announcement of the CD would be a good place to start. The public’s coolest tech to own in the 1970s was probably an analogue VCR or a CB radio, yet almost overnight they switched at the start of the ’80s to a CD player and a home computer. The CD player was the first place most consumers encountered a laser of their own, which gave it an impossibly futuristic slant, and the rainbow effect of the pits on a CD became a motif that wove its way into the design language of the era. Very few new technologies since have generated this level of excitement at their mere sight, instead today’s consumers accept new developments as merely incremental to the tech they already own while simultaneously not expecting them to have longevity.
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Hands-On: New Nvidia Jetson Nano Is More Power In A Smaller Form Factor

March 18, 2019 by Brian Benchoff 55 Comments

Today, Nvidia released their next generation of small but powerful modules for embedded AI. It’s the Nvidia Jetson Nano, and it’s smaller, cheaper, and more maker-friendly than anything they’ve put out before.

The Jetson Nano follows the Jetson TX1, the TX2, and the Jetson AGX Xavier, all very capable platforms, but just out of reach in both physical size, price, and the cost of implementation for many product designers and nearly all hobbyist embedded enthusiasts.

The Nvidia Jetson Nano Developers Kit clocks in at $99 USD, available right now, while the production ready module will be available in June for $129. It’s the size of a stick of laptop RAM, and it only needs five Watts. Let’s take a closer look with a hands-on review of the hardware.

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Es’hail-2: Hams Get Their First Geosynchronous Repeater

March 18, 2019 by Dan Maloney 27 Comments

In the radio business, getting the high ground is key to covering as much territory from as few installations as possible. Anything that has a high profile, from a big municipal water tank to a roadside billboard to a remote hilltop, will likely be bristling with antennas, and different services compete for the best spots to locate their antennas. Amateur radio clubs will be there too, looking for space to locate their repeaters, which allow hams to use low-power mobile and handheld radios to make contact over a vastly greater range than they could otherwise.

Now some hams have claimed the highest of high ground for their repeater: space. For the first time, an amateur radio repeater has gone to space aboard a geosynchronous satellite, giving hams the ability to link up over a third of the globe. It’s a huge development, and while it takes some effort to use this new space-based radio, it’s a game changer in the amateur radio community.

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Hitchhiking To The Moon For Fun And Profit

March 18, 2019 by Tom Nardi 43 Comments

On February 22nd, a Falcon rocket lifted off from Cape Canaveral carrying the Indonesian communications satellite Nusantara Satu. While the satellite was the primary payload for the mission, as is common on the Falcon 9, the rocket had a couple of stowaways. These secondary payloads are generally experiments or spacecraft which are too small or light to warrant a rocket of their own such as CubeSats. But despite flying in the economy seats, one of the secondary payloads on this particular launch has a date with destiny: Israel’s Beresheet, the first privately-funded mission to attempt landing on the Moon.

But unlike the Apollo missions, which took only three days to reach our nearest celestial neighbor, Beresheet is taking a considerably more leisurely course. It will take over a month for the spacecraft to reach the Moon, and it will be a few weeks after that before it finally makes a powered descent towards the Sea of Serenity, not far from where Apollo 17 landed 47 years ago. That assumes everything goes perfectly; tack a few extra weeks onto that estimate if the vehicle runs into any hiccups on the way.

At first glance, this might seem odd. If the trip only took a few days with 1960’s technology, it seems a modern rocket like the Falcon 9 should be able to make better time. But in reality, the pace is dictated by budgetary constraints on both the vehicle itself and the booster that carried it into space. While one could argue that the orbital maneuvers involved in this “scenic route” towards the Moon are more complicated than the direct trajectory employed by the manned Apollo missions, it does hold promise for a whole new class of lunar spacecraft. If you’re not in any particular hurry, and you’re trying to save some cash, your Moon mission might be better off taking the long way around.

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