Hackaday London Meet-up This Friday

September 11, 2017 by Mike Szczys 12 Comments

Hackaday takes over London at the end of this week. Join us on Friday night as we host a meetup at the Marquis Cornwallis, a pub in Bloomsbury.

This is a Bring-a-Hack style meetup, so grab something you’ve been working on to get the conversation flowing as you enjoy food and drink with members of the Hackaday community from the area. Also on hand from the Hackaday Crew will be [Mike Szczys], [Elliot Williams], [Jenny List], [Pedro Umbelino], and [Adil Malik]. We’re consistently delighted by the many and varied projects that show up — we want to meet you and hear about your project no matter how trivial, or involved. We do suggest you bring something handheld though, as tabletop space will be limited.

We’ve rented the upper floor of the pub and ordered food and fine beverages for all who attend. This is possible thanks to the support of DesignSpark, the exclusive sponsor of the Hackaday UK Unconference.

Tickets for that event have been sold out for ages now, so we’re glad to host a meetup to involve more of the UK Hackaday community. There are still a few left for this Friday Meetup so claim your free ticket now!

Doppler Module Teardown Reveals The Weird World Of Microwave Electronics

September 11, 2017 by Dan Maloney 19 Comments

Oscillators with components that aren’t electrically connected to anything? PCB traces that function as passive components based solely on their shape? Slots and holes in the board with specific functions? Welcome to the weird and wonderful world of microwave electronics, brought to you through this teardown and analysis of a Doppler microwave transceiver module.

We’ve always been fascinated by the way conventional electronic rules break down as frequency increases. The Doppler module that [Kerry Wong] chose to pop open, a Microsemi X-band transceiver that goes for about $10 on eBay right now, has vanishingly few components inside. One transistor for the local oscillator, one for the mixer, and about three other passives are the whole BOM. That the LO is tuned by a barium titanate slug that acts as a dielectric resonator is just fascinating, as is the fact that PB traces can form a complete filter network just by virtue of their size and shape. Antennas that are coupled to the transceiver through an air gap via slots in the board are a neat trick too.

[Kerry] analyzes all this in the video below and shows how the module can be used as a sensor. If you need a little more detail on putting these modules to work, we’ve got some basic circuits you can check out.

Continue reading “Doppler Module Teardown Reveals The Weird World Of Microwave Electronics” →

Wall fans for circulating hot ceiling air

Winter Is Coming: Keeping Heat Where It’s Needed

September 10, 2017 by Steven Dufresne 19 Comments

If your workshop has ceilings as high as [Niklas Roy]’s 3.6 meters (11.8 feet), then you’re familiar with his problem. Hot air rises, and there it usually stays until the heat is transferred outdoors. But in the winter time we need that heat indoors and down low. One solution is to install ceiling fans that blow that hot air back down. However, [Niklas] often builds tall things that would collide with those fans. And so he had to hack together some wall hugging fans which will be both high up and out of the way.

For the fans he’s using six of those ubiquitous standing fans, the ones that normally sit on a post a few feet off the ground and swivel back and forth. Discarding the posts, he mounted the fan bodies to a horizontal wooden frame with a wheel attached to one end, one that he’d made for another project. A rope around the wheel, and hanging down, makes it easy to tilt the fans. For controlling the fans, a friend had given him an old industrial controller, and opening it up, all he saw was corrosion. Cleaning it all out he installed an old Russian 3-position switch from his collection.

In the future he’d like to add a closed-loop control system that would not only turn the fans on and off but also adjusting their speed. For now, however, he reports that it works really well. Check out his page for build photos and more details.

Meanwhile, winter really is coming to these northern latitudes and so here are more hacks to prepare you. For automated shovelling snow, how about an RC controlled 3D printed snow blower. And while you’re snug and warm inside remotely controlling your snow blower, you can still be getting exercise using a DIY bicycle roller. But if you do venture outside, perhaps you’d want to zip around on a dogless dog sleigh.

Scribble Your Way To Quick Printed Circuit Boards

September 10, 2017 by Jenny List 44 Comments

There are a variety of techniques employed by electronic constructors seeking the convenience of a printed circuit board without the inconvenience of making a printed circuit board. Dead bug style construction in which the components float on a spiders-web of soldered leads above a ground plane is one, Manhattan style construction in which pads made from small cut squares of bare copper-clad PCB are glued on top of a groundplane is another.

[Freestate QRP] has another take on this type of electronics, with what he calls “Scribble style” construction. He cuts away copper from bare board to create pads and rudimentary tracks, and for him the magic ingredient comes from his choice of an engineer’s scribe to do the job. This is where the “scribble” comes from, creating a pad is as simple as drawing it with the scribe.

Of course, this technique is not entirely new, constructors have been doing this type of work for years with Dremel tools, hand engraving tools, and similar. If you’ve ever tried to do it with a knife or scalpel you will know that it’s hardly an easy task with those hand tools so the prospect of another one doing a better job is rather interesting. He’s ready and able to demonstrate it in action, showing us a couple of RF circuits using the technique.

Have you tried this technique, or one like it? How did you get on, tell us in the comments. Meanwhile, you might like to read our own [Dan Maloney]’s look at dead bug and Manhattan construction.

Hackaday Links: September 10, 2017

September 10, 2017 by Brian Benchoff 4 Comments

Hackaday is 13! We’re going through a bit of a rebellious phase. There’s hair where there wasn’t hair before. Thirteen years ago (Sept. 5, 2004), [Phil Torrone] published the first Hackaday Post. [Phil] posted a great writeup of the history of Hackaday over on the Adafruit blog — we were saved from the AOL borg because of the word ‘hack’ — and interviewed the former and current editors of your favorite DIY website. Here’s to 13 more years and to [Phil] finding a copy of the first version of the Jolly Wrencher designed in Macromedia Flash.

Hackaday is having an unconference in the UK! Tickets for next weekend’s event went fast, but don’t worry — we’re hosting a Bring A Hack the day before.

Hurricanes are an awesome force of nature. As we learned from Harvey a week ago, livestreamed footage from the eyewall of a hurricane is fascinating. [Jeff Piotrowski] seems to be the streamer of choice. If you’re looking for something to gawk at, here you go.

Another burn is over, and I still have no idea how they moved the fuselage of a 747 from Palmdale to the playa.

You know we’re doing this whole Hackaday Prize thing where we’re giving a ton of money to people for creating cool hardware, right? We’re almost done with that. The last round of The Hackaday Prize is going on right now. The theme is anything goes, or rather there is no theme. The goal of this round is to build cool stuff. This round ends on October 16th, and yes, we’ll have the results for the Assistive Technologies round out shortly.

[Prusa] makes a lot of printers, and that means he needs to make a lot of parts to make a lot of printers. Obviously, a PTFE-cutting robot is the solution to this problem

October 5th is the Open Source Hardware Summit in Denver. Hackaday and Tindie are going, and it’s going to be a blast. The location has moved in the last week — now it’s about half a mile away from the old venue. The speaker schedule is up, board nominations are open, and somewhere, someone is organizing a Lulzbot/Sparkfun booze cruise the day after the summit. I should be getting a van to add capacity to this trip, so if you’re interested leave a note in the comments.

Hackaday Prize Entry: IO, The Cardboard Computer

September 10, 2017 by John Baichtal 21 Comments

[Dr. Cockroach]’s goal was to build a four-bit computer out of recycled and repurposed junk. The resulting computer, called IO, consists of a single 555, around 230 PNP and NPN transistors, 230 diodes, and 460 resistors. It employs RISC architecture and operates at a speed of around 3 Hz.

He built IO out of cardboard for a good reason: he didn’t have a big budget for the project and he could get the material for free from his workplace. And because it was built so cheaply, he could also build it really big, allowing him to be able to really see each circuit close up and repair it if it wasn’t working right. You can really see the architecture very well when it’s this big—no tangle of wires for [Dr. Cockroach]. He uses over sixty blue LEDs to help monitor the system, and it doesn’t hurt that they look cool too. One of our favorite parts of the project is how he used copper fasteners to both manage the cardboard and serve as wiring points.

Continue reading “Hackaday Prize Entry: IO, The Cardboard Computer” →

A Great Guide To Software PLLs

September 10, 2017 by Jenny List 16 Comments

There are some things that you think you know quite well because you learned them in your youth and you understand their principles of operation. Then along comes a link in your morning feed that reminds you of the limits of your knowledge, and you realize that there is a whole new level of understanding to be reached.

Take Phase Locked Loops (PLLs) for example. You learn how they work, you use them for frequency synthesis, and you know they can do other things like recover noisy clock lines and do FM demodulation. But then you read [Paul Lutus’] Understanding Phase-Locked Loops page, and a whole new vista opens.

He’s discussing PLLs in the context of software, as part of a weather fax decoder project, and this allows a perspective that was unavailable to those of us who learned about them through the medium of hardware such as the venerable 4046 CMOS chip. We can easily look at different PLLs with varying parameters, for example their use with a narrowband loop filter to retrieve signals buried in the noise, all through some straightforward code tweaks rather than extensive circuitry. It’s a page that’s a few years old now, but resources like this one do not age.

If PLLs are entirely new to you then you need to reat last year’s excellent PLL primer by Hackaday’s own [Al Williams].

[via Hacker News]

[PLL diagram: Chetvorno CC0]