Linux-Fu: Running Commands

July 7, 2017 by Al Williams 26 Comments

One of the things that makes Linux and Unix-like systems both powerful and frustrating is that there are many ways to accomplish any particular goal. Take something simple like running a bunch of commands in sequence as an example. The obvious way is to write a shell script which offers a tremendous amount of flexibility. But what if you just want some set of commands to run? It sounds simple, but there are a lot of ways to issue a sequence of commands ranging from just typing them in, to scheduling them, to monitoring them the way a mainframe computer might monitor batch jobs.

Let’s jump in and take a look at a few ways you can execute sequences from bash (and many other Linux shells). This is cover the cron and at commands along with a batch processing system called task spooler. Like most things in Linux, this isn’t even close to a complete list, but it should give you some ideas on ways to control sequences of execution.

Continue reading “Linux-Fu: Running Commands” →

LCaaS – Lawn Care As A Service?

July 6, 2017 by Dan Maloney 71 Comments

As often happens while engaged in a mundane task, my mind wandered while I was mowing my small suburban plot of green this weekend. “Why, in 2017, am I still mowing the lawn?” In a lot of ways we’re living in the future — we walk around with fantastically powerful computers in our pockets, some of us have semi-autonomous cars, and almost anything can be purchased at the touch of a finger and delivered the next day or sooner. We even have robots that can vacuum the floor, so why not a robot lawnmower?

It turns out we do have robotic lawnmowers, but unfortunately, they kind of suck: Continue reading “LCaaS – Lawn Care As A Service?” →

Book Review: The Art Of The Patent

July 5, 2017 by Jenny List 22 Comments

In bringing suitable illustrations to our articles, we Hackaday scribes use a variety of sources that offer images featuring permissive licences. Among the usual free image libraries there is one particularly rich source, the line drawings contained within the huge archives of patents granted by the various countries around the world. These are the illustrations used as part of the patent itself to describe the working of the patent being claimed. We use them because though the items they depict are legally protected from copying by the patents they are part of, they as part of the patents themselves are in the public domain. Thus we can easily find detailed hand drawn pictures of all kinds of technical innovations from the last couple of hundred years or so, and from time to time you as our readers reap the benefit.

The beauty in hand-rendered fonts from patent artwork, collected within the book.

If you spend a while browsing old patents through a search engine such as Google Patents, you can quickly become engrossed in these beautiful images of inventions past. Though their purpose is a functional one to convey the workings of an invention, the anonymous artists have often poured all of their skill into rendering them as considerably more than mere draughtsmanship. In those dusty Government archives lurk masterpieces, just waiting to be found.

It seems we here at Hackaday are not alone in sharing a fascination with these images, for a US patent agent, [Kevin Prince], wrote a fascinating exploration of the medium in his book, The Art of the Patent. Continue reading “Book Review: The Art Of The Patent” →

Friday Hack Chat: A Design Slam Challenge

July 5, 2017 by Brian Benchoff 5 Comments

Every Friday, the Hackaday.io community gathers ’round the fireplace and discusses the challenges facing the world. This is the Hack Chat, and in previous incarnations, we’ve talked about custom silicon, Arduinos, PCB fabrication, old technologies, and hardware manufacturing.

For this week’s Hack Chat, we’re opening up a design challenge. We’re asking the community for help on developing a wireless position sensor. This is a Design Slam Hack Chat, and we’re looking for contributors.

Our guest for this week’s Hack Chat will be [Naveen Nair], technology leader for GE Fuse. We’ll be discussing position sensors during this Hack Chat. If you’ve ever used a mouse, you’re using a position sensor, but for this Hack Chat we’re designing something a little more challenging. The Fuse group is attempting to build a low-cost, wireless position sensor with hand-held ultrasonic inspection units. Why is GE interested in this technology? Our guess is inspecting jet turbines, or something like that. That doesn’t mean low-cost wireless position sensors wouldn’t have other applications, though. Just imagine what a quadcopter could do if it could sense its position with 1mm resolution.

Won’t be able to make the Hack Chat? Don’t worry, we’ll be putting a transcript up here sometime after the event.

Here’s How To Take Part:

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This Hack Chat will take place at noon Pacific time on Friday, July 7th. Confused about where and when ‘noon’ is? Here’s a time and date converter!

Log into Hackaday.io, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Retrotechtacular: DC To DC Conversion, Rotary Style

July 4, 2017 by Al Williams 24 Comments

If you want to convert one voltage to another, what do you do? Well, if you are talking DC voltages today, you’ll probably use a DC to DC converter. Really, these converters generate some sort of AC waveform and then use either an inductor or a transformer to boost or buck the voltage as desired. Then they’ll convert it back to DC. If you are talking AC voltages, you could just use a transformer. But think about this: a transformer has two sides. The primary makes an alternating magnetic field. Just like rotating a shaft with magnets on it could. The secondary converts that alternating magnetic field into electricity just like a generator does. In other words, a transformer is just a generator that takes an AC input instead of a rotating mechanical input.

That’s a bit of an oversimplification, but in the old days, a lot of mobile radios (and other devices) took this idea to its logical conclusion. A M-G (Motor Generator) set was little more than a motor connected to a generator. The motor might take, say, 12V DC and the output could be, for example 300V AC that would get rectified for the plate voltage in a tube radio.

Continue reading “Retrotechtacular: DC To DC Conversion, Rotary Style” →

Hackaday Links: July 2, 2017

July 2, 2017 by Brian Benchoff 55 Comments

A few months ago, we had a Hack Chat with Chip Gracey, the guy behind Parallax, the Basic Stamp, the Propeller, and the upcoming Propeller II. Now we’ve finally got around to editing that transcript. There’s a lot of awesome stuff in here, from learning a Hardware Design Language to the actual costs of fabbing silicon.

Rigol, the manufacturers of every hackerspace’s favorite oscilloscope, announced a new chipset. The current lineup of Rigol scopes top out at around 1GHz. In a prototype scope based on this chipset, Rigol demonstrated 4GHz bandwidth and 20GS/s with one Billion point memory depth. What this means: Rigol will be making very powerful scopes in the near future.

Hackaday had a meetup this week in New York City. The June workshop at Fat Cat Fab Lab featured speakers involved with twitter bots, 8-bit art, one of the guys behind Beautiful Soup, and a talk on a completely self-sustainable record label. Want to attend one of these meetups? Check out the calendar.

Repairs of retrocomputers are always interesting, but usually the same. Wipe off some dust, possibly replace a cap or two, retrobrite the case, and you’re done. This is not the usual retrocomputer repair. [Drygol] found a C64 that was apparently stored in a swamp for several years. The power switch fell off when he touched it. Somehow, miraculously, the circuit worked and [Drygol] rewarded the board with a new enclosure, dyed keycaps, an SD2IEC mod, and a kernel switch mod.

Guess what’s back? A pen computer with a color sensor on one end, and an ink mixer in the other. The Scribble Pen is the Internet’s infamous crowdfunded color-sensing pen, and the scammer behind it is looking for another funding round. Has anything changed since we tore this thing apart three years ago? No, it’s still a scam. I’ve been keeping tabs on the guy behind it, he’s still not in prison, and there are still idiots on this planet.

The ‘A’ stands for ‘Arts’.

The Benchy is everyone’s favorite tugboat and 3D printer benchmarking tool. They usually float, sideways. However, [MakeShift] somehow figured out how to add weight to the keel and turn the cutest little tugboat into a real, remote controlled boat. You could probably model a proper hull for the bottom of this boat, and it would be one of the few 3D prints where the actual design would be subject to US Copyright.

Is the fidget spinner fad dying? Square, the startup built around turning old AUX to cassette adapters into POS terminals seems to think so. They’ve been graphing their sales figures for fidget spinners, and there has been a marked decline since school let out for the summer. Will the trend pick back up in September? Who cares.

Will It Sell?

June 29, 2017 by Bob Baddeley 86 Comments

Many of us develop things for one of two purposes: to hack something cool, or to sell something cool. When hacking something cool, your target market is yourself, and you already know you’ve made the sale. If your goal is to sell the thing you are making, then a lot more thought and effort is required. You could develop the coolest product in the world, but if your target market is too small, your price is too high, your lead time is too long, or any of a dozen other factors is not quite right, you’ll be spending a lot of time and effort on what will amount to a huge disappointment. The Hackaday Prize Best Product has many great examples which let us study some of these success factors, so let’s take a look. Continue reading “Will It Sell?” →