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10 Jan 08:20

How To Build A Fully Offline Smart Home, Or Why You Should Not

by Maya Posch

So-called ‘smart home’ appliances and gadgets have become an ever-more present thing the past years, with nary a coffeemaker, AC unit or light bulb for sale today that doesn’t have an associated smartphone app, cloud service and/or subscription to enable you to control it from the beach during your vacation, or just set up automation routines to take tedium out of your busy schedule. Yet as much as [Calvin Wankhede] loves home automation, he’d very much like for it to not stop working the moment his internet connection goes down, or the company running the service goes bankrupt. This is where his journey to create an off-line alternative smart home based around Home Assistant and other (open) software began.

Although Home Assistant (HA) itself has become significantly easier to use, what becomes readily apparent from [Calvin]’s journey is that setting up and managing your own smart home infrastructure is a never-ending project. A project that involves finding compatible hardware that can tie into HA, whether or not without reflashing the firmware, resolving configuration issues and other assorted fun. If you are into this kind of thing, it is of course a blast, and it’s a good feeling when it finally all works.

Unfortunately, interoperability across smart home and similar IoT devices is still a far-off dream, even with the introduction of Thread and Matter (which incidentally are among the worst product names to search for, period), as Matter’s uptake is pretty abysmal. This thus leaves off-line smart homes mostly as the domain of the tech-inclined in search of a hobby.

28 Nov 08:48

Tektronix’s Ceramic CRT Production And The Building 13 Catacombs

by Maya Posch

As a manufacturer of test equipment and more, Tektronix has long had a need for custom form factors with its CRT displays. They initially went with fully glass CRTs as this was what the booming television industry was also using, but as demand for the glass component of CRTs increased, so did the delays in getting these custom glass components made. This is where Tektronix decided to use its existing expertise with ceramic strips during the pre-PCB era to create ceramic funnels for ceramic CRTs, as described in this 1967 video.

The Tektronix ceramic CRT molds underneath Building 13.
The Tektronix ceramic CRT molds underneath Building 13.

Recently, underneath Building 13 at the Tektronix campus, a ‘catacomb’ full of the molds for these funnels was discovered, covering a wide range of CRT types, including some round ones that were presumably made for military purposes, such as radar installations. These molds consist out of an inner part  (the mandrel) made from 7075-T6 aluminium, and an outer cast polyurethane boot. The ceramic (forsterite) powder is then formed under high pressure into the ceramic funnel, which is then fired in a kiln before a full inspection and assembly into a full CRT, including the phosphor-coated glass front section and rear section with the electron guns.

The advantages of ceramic funnels over glass ones are many, including the former being much harder and resilient to impact forces, while offering a lot of strength for thinner, lighter structures, all of which is desirable in (portable) lab equipment. Although LCDs would inevitably take over from CRTs here as well, these ceramic CRTs formed an integral part of Tektronix’s products, with every part of production handled in-house.

11 Jul 05:44

Masking Tape Pen Plotter Gets an Upgrade

by Chris Lott

[Mr Innovative] decided to make his version of a small pen plotter (video after the break) to make labels on masking tape. The result is an impressive compact machine that is remotely controlled using your smartphone. The plotter is constructed using several different techniques, a piece of plywood as the base, a 3D printed bracket for the motors and pen carriage, and a routed acrylic plate that holds the lead screw and linear rail assembly. The whole thing is controlled by an Arduino Nano mounted on a custom motor driver carrier board.

The inspiration for this build came from a project by [michimartini] aka [Molten Cheese Bear] that we covered a few months ago. [Mr Innovative] went for belt vs direct drive and no local screen. It also appears to plot a little bit faster, but that might be due to differences in the ink pens used. An Android app called TextToCNC converts label text into G-Code, and the Grbl Controller app sends those commands to the plotter.

We like continued iterations of open source projects and look forward to seeing what the next generations look like. Thanks to [keithfromcanada] for submitting this tip.

29 Sep 05:12

Microwave Ovens: Need More Power? Use Lasers Instead!

by Dave Rowntree

You know how it is, you get in late from work, you’ve been stuck in traffic for what seems like an eternity, and you’re hungry. You reach for the microwave meal, and think, if only I didn’t have to wait that three-and-a-half minutes, 900 watts just isn’t enough power. What you need is a laser microwave, and as luck would have it, [Styropyro] has built one, so you don’t have to. No, really, don’t.

After he observed a microwave only operating on a half-wave basis, and delivering power 50% of the time, he attempted to convert it to full-wave by doubling up the high voltage transformer and rectification diodes. While this worked, the poor suffering magnetron didn’t go the full mile, and died somewhat prematurely.

Not to be disheartened, the obvious thing was to ditch the whole concept of cooking with boring old radio waves, and just use a pile of frickin’ lasers instead. Now we’re not sure how he manages to get hold of some of the parts he uses, and the laser array modules look sketchy to say the least, and to be frank, we don’t think they should be easy to get given the ridiculous beam power they can muster.

With the build completed to the usual [Styropryo] level of excellent build quality, he goes on to produce some mouthwatering delicacies such as laser-charred poptart, incinerated steak with not-really-caramelised onions and our favourite laser-popcorn. OK, he admits the beam has way too much power, really should be infrared, and way more diffuse to be even vaguely practical, but we don’t care about practicality round these parts. Who wouldn’t want the excitement of going instantly blind by merely walking into the kitchen at the wrong time?

We’ve covered a fair few microwave oven related hacks before, including a neat microwave kiln, and hacks using microwave parts, such as a janky Jacob’s ladder, but this is probably the first laser microwave we’ve come across. Hopefully the last :)

And remember kids, as [Styropyro] says in pretty much every video on his channel:

All the crazy stuff you’re about to do was done for educational purposes, in fact if you were to try any of this stuff at home, you’d probably die…

 

 

01 Feb 03:16

Crosswords Help You Learn Regular Expressions

by Al Williams

Regular expressions might seem arcane, but if you do any kind of software, they are a powerful hacker tool. Obviously, if you are writing software or using tools like grep, awk, sed, Perl, or just about any programming language, regular expressions can simplify many tasks. Even if you don’t need them directly, regular expression searches can help you analyze source code, search through net lists, or even analyze data captured from sensors.

If you’ve been using regular expressions for a long time, they aren’t very hard. But learning them for the first time can be tedious. Unless you try your hand at regular expression crosswords. The clues are regular expressions and the rows and columns all have to match the corresponding regular expressions.

For example, consider this puzzle (which is already filled out):

crossex

This puzzle has a theme (The Beatles). The first across clue says that the two characters have to be an HE or an LL or one or more Os (two, then, in this case). The first down clue says the characters can’t be S, P, E, A, or K. So even though the second across clue says the lower left cell could be an A (in PLEASE), that would violate the down clue.

Of course, this is a super simple puzzle, but the site has many more puzzles of increasing difficulty. If you prefer your puzzles in hardware, that’s ok. If you want to work a different kind of puzzle, you might look at our Omnibus.


Filed under: Software Development
03 Dec 05:09

DIY Lamps Brighten Winter Blues

by Kristina Panos

As you know, winter is coming. For a lot of people this means that Seasonal Affective Disorder is beginning to set in. [Luke]’s mom already has a light therapy box. It’s one of those commercially available ones that uses fluorescent bulbs and leaves a lot to be desired in the full-spectrum light simulation department. [Luke] jumped on the opportunity to design a better one.

The standard of quality for light therapy units is a rating of 10,000 lux. While lux definitely matters, the rating is a misleading selling point when given on its own. One of the other important factors in mimicking the sun is the Color Rendering Index (CRI). CRI is basically a rating of the bulb’s ability to imitate the color reproduction of natural daylight. The ratings run from 0 to 100 but in reality, the highest-rated bulbs of any kind top out around 98.

For all the fluorescent bulb-bearing light therapy units out there, those bulbs have pretty low CRI ratings. [Luke]’s project page provides emission spectra graphs for a number of bulb types, and we can see how his choice of ceramic metal halide bulbs stacks up against fluorescent, incandescent, and LED bulbs. One of the few downsides to this type of bulb is that they have long startup times.

He ended up making two light therapy lamps, one of them directional and the other omni-directional. They both use ballast-controlled ceramic metal halide bulbs. The ballasts are necessary to provide the high starting voltage that these bulbs require. The omni-directional light is built into a large hurricane candle holder. A lamp holder is fixed into the base and wired to an external ballast box. The directional lamp is a self-contained unit, and [Luke] is happiest with this one. It’s flat and rugged so it can be placed on top of a bookcase and the light bounced off of the ceiling for pleasant, indirect coverage.

We’ve seen a couple of alarm-clock wakeup light builds here, and we’re thinking this would make an awesome mashup.


Filed under: lifehacks
15 Jun 13:05

The Small & Cheap miniSpartan6+

by Brian Benchoff

FPGA

There have been quite a few boards put out in recent months with an FPGA, some RAM, Flash, and a bunch of I/O, the working theory being FPGAs are the new hotness, ready to steal the crown from Arduino and put a programmable logic development board in the hands of millions. We’re not so sure that’s going to happen. but Scarab Hardware’s miniSpartan6+ board does look pretty nice, and has more than enough on board to serve as anyone’s first FPGA platform. It’s also one of the first FPGA boards we’ve seen that is breadboard friendly. Nice touch.

This tiny board features a Spartan6 LX9 FPGA, with just under 10,000 logic cells. An FPGA platform is useless without some sort of IDE, so the Scarab Hardware folks have taken the Mojo IDE, improved the GUI, added a few libraries, and rolled everything up into a ‘not the Arduino IDE, but as simple and better’ platform.

Right now, the crowdfunding campaign for the miniSpartan6+ is well over 200% funded with a little less than a month to go. The stretch goals the team have in mind – a very likely probability, given what they’re asking – include a faster FPGA, a higher resolution ADC, and support for HDMI input and output. That last bit – HDMI input – will allow anyone to do some cool things like overlaying video with HDMI for a pretty reasonable cost.


Filed under: Crowd Funding
16 Apr 02:16

Automated Bed Leveling For 3D Printers Is Now Solved

by Brian Benchoff

bed

The latest and greatest feature for 3D printers – besides being closed source, having no meaningful technical specs, and being on track towards pulling in $10 Million on a Kickstarter – is automated bed leveling. This amazingly useful feature makes sure your prints have proper adhesion to the bed, reduce print errors, and put even inexpensive printers into the realm of extremely expensive professional machines. Automated bed leveling has been extremely hard to implement in the past, but now [Scottbee] has it figured out with a working prototype on his Makerbot Replicator 2X.

Earlier attempts at automated bed leveling used some sort of probe on the tool head to measure the build plate, calculate its flatness and orientation in space, and compensate for any tilt in software. [Scottbee]‘s solution to the problem took a different tack: instead of trying to compensate for any odd orientation of the build surface in software, he’s simply making the bed level with a series of springs and cam locks.

[Scottbee]‘s device levitates the build plate on three springs, and replaces the jack screws with three “gimballing pins” and pin locks. With the pin locks disengaged, the bed plate is pressed down with the printer’s nozzle. By moving the extruder across the build plate and locking the pins in place one by one, [Scottbee]‘s device defines the plane of the build plate along three points. This makes the build platform parallel to the extruder nozzle, and also has a nice benefit of setting the distance from the build platform to the nozzle precisely with incredible repeatability.

The mechanics of locking the three gimballing pins in place  only requires a single DC gear motor, driven by an extra fan output on the Makerbot’s electronics. It’s simple, and with a bit of rework, it looks like most of the device could also be 3D printed.

An awful lot of RepRaps and 3D printers out there already use three points to attach the build plate to a frame. With a little bit of effort, this same technique could be ported and made a bit more generic than the Makerbot-based build seen above. It’s amazingly simple, and we can’t wait to see this applied to a normal RepRap.

Thanks [Josh] for the tip.


Filed under: 3d Printer hacks
01 Feb 14:17

Is Peter Capaldi's new costume a callback to a classic Doctor Who?

by Ria Misra

Is Peter Capaldi's new costume a callback to a classic Doctor Who?

So, we've finally gotten a look at the outfit Peter Capaldi will be wearing as the Doctor. And while it's a brand new look, it's also strangely familiar.

Read more...