The Sunday Morning Breakfast Machine

July 5, 2016 by Jenny List 13 Comments

Breakfast is a meal taken very seriously indeed by Brits. So seriously that continual attempts have been made to perfect the experience mechanically. Who could not delight to be woken up by a Teasmade alarm clock delivering a fresh cup of hot beverage, and where else would the getting out of bed sequence in Wallace and Gromit be, not the comedic animated film, but a documentary?

Latest in a long line of British builders of mechanical morning repast generators are [Peter Browne] and [Mervyn Huggett]. Working from a garden shed – where else! – in Sussex, they have spent three months and a thousand man hours creating their “Sunday Morning Breakfast Machine“, designed to cook and serve a slice of toast and a boiled egg alongside a cup of tea or coffee and the morning paper. Prototyping was done in Meccano , could there be any other medium for a machine like this one?

The machine itself is a mix of the practical and the whimsical. The giant-sized facsimile of a vintage Ever Ready battery and the toy rooster hide some pretty accomplished metalwork and control systems. They do admit that the primary purpose is to make people laugh, but it does the job, albeit with what looks like a leak from a cracked egg.

A full description from [Peter] is in the video below the break.

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Retrotechtacular: How Solidarity Hacked Polish TV

July 5, 2016 by Jenny List 52 Comments

In the 1980s, Poland was under the grip of martial law as the Communist government of General Wojciech Jaruzelski attempted to repress the independent Solidarity trade union. In Western Europe our TV screens featured as much coverage of the events as could be gleaned through the Iron Curtain, but Polish state TV remained oblivious and restricted itself to wholesome Communist fare.

In September 1985, TV viewers in the city of Toruń sat down to watch an action adventure film and were treated to an unexpected bonus: the screen had a brief overlay with the messages “Solidarity Toruń: Boycotting the election is our duty,” and “Solidarity Toruń: Enough price hikes, lies, repression”. Sadly for the perpetrators, they were caught by the authorities after their second transmission a few days later when they repeated the performance over the evening news bulletin, and they were jailed for four months.

The transmission had been made by a group of dissident radio astronomers and scientists who had successfully developed a video transmitter that could synchronise itself with the official broadcast to produce an overlay that would be visible on every set within its limited transmission radius. This was a significant achievement using 1980s technology in a state in which electronic components were hard to come by. Our description comes via [Maciej Cegłowski], who was able to track down one of the people involved in building the transmitter and received an in-depth description of it.

Transmission equipment seized by the Polish police.

The synchronisation came courtesy of the international effort at the time on Very Long Baseline Interferometry, in which multiple radio telescopes across the world are combined to achieve the effect of a single much larger instrument. Before GPS made available a constant timing signal the different groups participating in the experiment had used the sync pulses of TV transmitters to stay in time, establishing a network that spanned the political divide of the Iron Curtain. This expertise allowed them to create their transmitter capable of overlaying the official broadcasts. The police file on the event shows some of their equipment, including a Sinclair ZX Spectrum home computer from the West that was presumably used to generate the graphics.

There is no surviving recording of the overlay transmission, however a reconstruction has been put on YouTube that you can see below the break, complete with very period Communist TV footage.

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A Very Tidy Circular Saw Bench

July 4, 2016 by Jenny List 16 Comments

If your parents had a workshop as you grew up, the chances are it harbored some tools you came to know and love as you used them for your formative projects. Our reader [Joerg]’s father for instance has a circular saw bench that [Joerg] sorely misses, now living over 500km away. Our subject today is his response to this problem, now needing to cut aluminium he set about creating a saw bench of his own, and the result is a rather nice build.

He put together a variety of CAD models to formulate his ideas, and arrived at a structure in 18mm waterproof plywood with moving table linear bearings. The saw blade itself was mounted on a 5mm aluminum plate, though he doesn’t tell us what motor it uses. All the wooden parts came from a single sheet of plywood, and the result is a very tidy creation indeed.

Power saws are among the more hazardous tools in your workshop arsenal, whatever their type. If this was a commercial saw it would probably have a guard over the top of its blade, but even without that its sturdy construction and relatively low profile blade make this one stand above some of the more basic home-made saws we’ve seen. Building a power saw is something you have to take seriously.

We’ve featured quite a few home-made saws over the years. At least one other large table saw, a rather powerful but surprisingly tiny saw bench, this scroll saw using a sewing machine mechanism, or how about this simple jigsaw table?

Emulating A Remote Control Ceiling Fan Transmitter In An FPGA

July 4, 2016 by Jenny List 7 Comments

[Joel] has a remote control ceiling fan. It’s nothing special, the controller has a low-power 350MHz transmitter and a Holtek encoder to send commands by keying the transmitter’s output. Desiring something a little better, he set about reverse engineering the device’s protocol and implementing it on a Lattice iCE40 FPGA.

To decode the device’s packets he reached for his RTL-SDR receiver and took a look at it in software. GQRX confirmed the presence of the carrier and allowed him to record a raw I/Q file, which he could then supply to Inspectrum to analyse the packet structure. He found it to be a simple on-off keying scheme, with bits expressed through differing pulse widths. He was then able to create a Gnu Radio project to read and decode them in real time.

Emulating the transmitter was then a fairly straightforward process of generating a 350MHz clock using the on-board PLL and gating it with his generated data stream to provide modulation. The result was able to control his fan with a short wire antenna, indeed he was worried that it might also be doing so for other similar fans in his apartment complex. You can take a look at his source code on GitHub if you would like to try something similar.

It’s worth pointing out that a transmitter like this will radiate a significant amount of harmonics at multiples of its base frequency, and thus without a filter on its output is likely to cause interference. It will also be breaking all the rules set out by whoever the spectrum regulator is where you live, despite its low power. However it’s an interesting project to read, with its reverse engineering and slightly novel use of an FPGA.

Wireless remote hacking seems to be a favorite pastime here in the Hackaday community. We’ve had 2.4GHz hacks and plenty of wireless mains outlet hacks.

IPhone Polarizing Camera Solves Filter Orientation Problem Using Flash

July 4, 2016 by Jenny List 6 Comments

One of last year’s Hackaday Prize finalists was the DOLPi, [Dave Prutchi]’s polarimetric camera which used an LCD sheet from a welder’s mask placed in front of a Raspberry Pi camera. Multiple images were taken by the DOLPi at different polarizations and used to compute images designed to show the polarization of the light in each pixel and convey it to the viewer through color.

The polarizer and phototransistor taped to the iPhone.

[Dave] wrote to tip us off about [Paul Wallace]’s take on the same idea, a DOLPi-inspired polarimetric camera using an iPhone with an ingenious solution to the problem of calibrating the device to the correct polarization angle for each image that does not require any electrical connection between phone and camera hardware. [Paul]’s camera is calibrated using the iPhone’s flash. The light coming from the flash through the LCD is measured by a phototransistor and Arduino Mini which sets the LCD to the correct polarization. The whole setup is taped to the back of the iPhone, though we suspect a 3D-printed holder could be made without too many problems. He provides full details as well as code for the iPhone app that controls the camera and computes the images on his blog post.

We covered the DOLPi in detail last year as part of our 2015 Hackaday Prize finalist coverage. You can also find its page on Hackaday.io, and [Dave]’s own write-up on his blog.

Hackaday Prize Entry: A Minimal ATtiny Voltage And Frequency Counter

July 2, 2016 by Jenny List 4 Comments

Sometimes when you build something it is because you have set out with a clear idea or specification in mind, but it’s not always that way. Take [kodera2t]’s project, he set out to master the ATtiny series of microcontrollers and started with simple LED flashers, but arrived eventually at something rather useful. An ATtiny10 DVM and DFM all-in-one with an i2c LCD display and a minimum of other components.

The DFM uses the ATtiny’s internal 16 bit timer, which has the convenient property of being able to be driven by an external clock. The frequency to be measured drives the timer, and the time it returns is compared to the system clock. It’s not the finest of frequency counters, depending as it does on the ATtiny’s clock rather than a calibrated crystal reference, but it does the job.

The results are shown in the video below, and all the code has been posted in his GitHub repository. We can see that there is the basis of a handy little instrument in this circuit, though with the price of cheap multimeters being so low even a circuit this minimal would struggle to compete on cost.

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A Strandbeest Bicycle

June 30, 2016 by Jenny List 20 Comments

“If you’re asking ‘why,’ you don’t get it.” So said [JP] when he told us about his strandbeest bicycle build. After all, who in their right mind would graft a complex multi-leg mechanical walking mechanism to the rear end of a perfectly good bicycle? But to expand on his sentiment, to not understand his creation is to miss the whole essence of our movement. Sometimes you just have to make something, because you can.

3D printed strandbeest bike proof of concept

If you aren’t familiar with the strandbeest, it is the creation of Dutch artist [Theo Jansen]. Complex skeletal walking machines powered by the wind, that in the case of [Jansen]’s machines autonomously roam the beaches of the Netherlands. Hence the name, from Dutch: “Beach beast”.

[JP]’s strandbeest bike came together over 8 months of hard work. It started with a conceptual CAD design and 3D print, and progressed through many iterations of fine-tuning the over 400 parts required to put four legs on the back of a bicycle frame. It’s an impressive achievement and it is fully rideable, though we suspect we won’t be seeing it at the Tour de France any time soon.

He’s posted several videos of the bike in action, you can see one of them below the break.

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