The Icoboard is a plug-in for the Raspberry Pi with a Lattice iCE FPGA onboard. Combined with a cheap A/D converter, [OpenTechLab] build a software-defined radio using all open source tools. He found some inexpensive converters that cost about $25 and were fast enough (32 MHz) for the purpose at hand. The boards also had a digital to analog converter and he was able to find the data sheets. You can see a video with the whole project covered, below.
The video, by the way, is pretty extensive (about an hour’s worth) and covers the creation of a PC board to connect from the Icoboard to the converters. There’s also a 3D printed frame, and that’s explained in detail as well.
[Claudio] covers everything from tearing down the broken iron to crafting a new tip that avoids problems with water droplets condensing on the brass tip that he used first. After salvaging the switch in the head that controls the steam, he carved a wooden handle that is soaked and coated with high-temperature resin. The hot end was then reinstalled, and the whole thing put together.
This build should be approached with some caution, though: anything that mixes high-pressure steam with electricity has the potential to go wrong in unpleasant ways, so be careful out there.
Those of us who aren’t familiar with woodworking might not expect that this curved wood and acrylic LED lamp by [Marija] isn’t the product of fancy carving, just some thoughtful design and assembly work. The base is a few inches of concrete in a plastic bowl, then sanded and given a clear coat. The wood is four layers of beech hardwood cut on an inverted jigsaw with the middle two layers having an extra recess for two LED strips. After the rough-cut layers were glued together, the imperfections were rasped and sanded out. Since the layers of wood give a consistent width to the recess for the LEDs, it was easy to cut a long strip of acrylic that would match. Saw cutting acrylic can be dicey because it can crack or melt, but a table saw with a crosscut blade did the trick. Forming the acrylic to match the curves of the wood was a matter of gentle heating and easing the softened acrylic into place bit by bit.
Giving the clear acrylic a frosted finish was done with a few coats of satin finish clear coat from a spray can, which is a technique we haven’t really seen before. Handy, because it provides a smooth and unbroken coating along the entire length of the acrylic. This worked well and is a clever idea, but [Marija] could still see the LEDs and wires inside the lamp, so she covered them with some white tape. A video of the entire process is embedded below.
Every now and then something old comes along which we’re surprised has never been on Hackaday. That’s especially the case here since it includes nixie tubes and is a clock, two things beloved here by many. Then again, it’s not a hack, but it just should be (hint hint).
Pulsar mystery clock
2001: A Space Odyssey clock
This clock’s origins are a bit of a mystery. As detailed in [Asto_Vidatu]’s Reddit post, he found it when cleaning out his mother’s garage. Larger photos of the clock internals are on his imgur page and are sure to delight and intrigue you. It looks very much like a clock widely thought to be the one which the Hamilton Watch Company made for Stanley Kubrick. In 1966, Kubrick commissioned Hamilton to make a futuristic looking clock and watches for his upcoming movie, 2001: A Space Odyssey. The watches appear in the movie on the wrists of the astronauts but the clock was left on the cutting room floor. After the movie was made, Kubrick gave the clock back to Hamilton, and it ended up in the possession of [Asto_Vidatu]’s grandfather, who worked on the team which made the clock.
All this might lead you to think that this is the clock made for the movie, instead of the one with the name Hamilton on it but the name Pulsar is thought to have been dreamed up around the time the movie came out. So where did it come from? Was it a hack by [Asto_Vidatu]’s grandfather or others at Hamilton? Was it a product which Hamilton had worked on, or perhaps a marketing gimmick for the Pulsar watch?
You would be forgiven for thinking that 3D printing is only about plastic filament and UV-curing resin. In fact, there are dozens of technologies that can be used to create 3D printed parts, ranging from welders mounted to CNC machines to the very careful application of inkjet cartridges. For this year’s Hackaday Prize, [Yvo de Haas] is modifying inkjet technology to create 3D objects. If he gets this working with off-the-shelf parts, this will be one of the most interesting advances for 3D printing in recent memory.
The core of this build is a modification of HP45 inkjet print heads to squirt something other than overpriced ink. To turn this into a 3D printer, [Yvo] is filling these ink cartridges with water or alcohol. This is then printed on a bed of powder, either gypsum, sugar, sand, or ceramic, with each layer printed, then covered with a fine layer of powder. All of this is built around a 3D printer with an X/Y axis gantry, a piston to lower the print volume, and a roller to draw more powder over the print.
The hardest part of this build is controlling the inkjet cartridge itself, but there’s prior work that makes this job easier. [Yvo] is successfully printing on paper with the HP45 cartridges, managing to spit out 150 x 150 pixel images, just by running the cartridge over a piece of paper. Already that’s exceptionally cool, great for graffiti, and something we can’t wait to see in a real, working printer.
You can check out [Yvo]’s handheld printing efforts below.
When a 13-year old Marie-Sophie Germain was stuck in the house because of the chaotic revolution on the streets of Paris in 1789, she found a refuge for her active mind: her father’s mathematics books. These inspired her to embark on pioneering a new branch of mathematics that focussed on modeling the real world: applied mathematics.
Post-revolutionary France was not an easy place for a woman to study mathematics, though. She taught herself higher maths from her father’s books, eventually persuading her parents to support her unusual career choice and getting her a tutor. After she had learned all she could, she looked at studying at the new École Polytechnique. Founded after the revolution as a military and engineering school to focus on practical science, this school did not admit women.
Anyone could ask for copies of the lecture notes, however, and students submitted their observations in writing. Germain got the notes and submitted her coursework under the pseudonym Monsieur Antoine-August Le Blanc. One of the lecturers that she impressed was Joseph Louis Lagrange, the mathematician famous for defining the mathematics of orbital motion that explained why the moon kept the same face to the earth. Lagrange arranged to meet this promising student and was surprised when Germain turned out to be a woman.
Gauss and Germain
‘Le Blanc’ also corresponded with German mathematician Carl Friedrich Gauss on number theory. When Napoleon’s armies occupied the town the famous mathematician lived in, Germain enlisted a family friend in the army to check that Gauss had not been harmed. Gauss didn’t realize who had helped him out, until he discovered that ‘Le Blanc’ was Sophie Germain, he wrote to her thanking her for her concern and praising her mathematical prowess given the hurdles set before her.
“How sweet is the acquisition of a friendship so flattering and precious to my heart. The lively interest you took during this terrible war deserves the most sincere recognition….But when a person of this sex, who, for our mores and prejudices, must recognize infinitely more obstacles and difficulties than men to become acquainted with these thorny searches, knows how to get rid of these obstacles and to penetrate what they have, most hidden, must undoubtedly, she has the most noble courage, talents quite extraordinary, genius superior.”
As well as working on the thorny and theoretical problems of number theory, Germain worked on applying mathematics to real world problems. One of these was a challenge set by the Paris Academy of Science to mathematically describe the elasticity of metal plates. An experimenter called Ernest Chladni had demonstrated that a metal plate would resonate in odd ways when vibrated at certain frequencies. If you put sand on the plate, it would collect in different patterns created by the resonance of the plate, called Chladni figures. To win the prize, the solution had to predict these figures.
The Mathematics of Stress and Strain
Mathematically predicting the behavior of metal plates could make it easier to design metal objects and predict how they would behave under stress. The prize was set in 1808 but was so difficult that Germain was the only one who decided to try to solve it, as it required coming up with a whole new way to analyze and describe how materials bend and change under stress.
The first two solutions that she submitted were rejected due to mathematical errors, but the third version won her the prize in 1816. However, due to the Academy policy of not allowing women to join (and to only attend events if they were wives of members), Germain was not able to attend the ceremony where the prize was granted. She was also not allowed to attend meetings of the Academy. After the Academy failed to publish her prize-winning work, Germain had to pay to publish the work herself in 1821.
Later, her friend Joseph Fourier allowed her to attend meetings and presentations, but the mathematical establishment never really accepted her, or her work. In a letter to a colleague in 1826 she complained about the way they rebuffed her:
“These facts are my domain and it is to me alone that they remain hidden. That’s the privilege of the ladies: they get compliments and no real benefits.”
In the same letter, Germain complained of suffering fatigue and she was diagnosed with breast cancer shortly afterwards. She died in 1831. Her final years were spent working on a solution to Fermat’s Last Theorem, and just before her death she published a partial solution that was the basis for much research into the theorem, which was finally solved only with computer help in the late 1990s.
Although Sophie Germain never earned a degree in her lifetime, she was given an honorary degree in 1837 from the University of Göttingen at the suggestion of Gauss, who noted that
“she proved to the world that even a woman can accomplish something worthwhile in the most rigorous and abstract of the sciences and for that reason would well have deserved an honorary degree.”
The Academy that snubbed her also now offers an annual prize for mathematics in her name. Perhaps more importantly, her work formed the basis of the study of elasticity and stress in metals that allowed engineers to build larger objects and buildings. Creations such as the Eiffel tower in 1887 were directly influenced by her work, and it laid some of the groundwork for Einstein’s theory of General Relativity.
Modern scholars argue that Germain could have been more than she was: her work, they argue, was hamstrung by a limited understanding of some of the fundamental concepts that Gauss and others had described. Although her work was fundamental and important, if she had been given free access to the education that she wanted and deserved, it’s easy to imagine that she would have gone farther.
For the uninitiated, a Theremin is a touch-less synthesizer that uses human capacitance and a pair of antennae to control oscillation and amplitude. In a light-based Theremin such as this one, the oscillation is controlled by the intensity of photons from a white LED and their interaction with a light-dependent resistor, also known as a photocell or ‘squiggly resistor’.
The oscillations themselves are created by wiring up the 555 as an astable oscillator, and the pitch is controlled with a potentiometer mounted on the back. It has a small built-in speaker, but [lonesoulsurfer] replaced the B button with a 3.5 mm audio jack so he can plug it into a powered speaker and really rock out. We’ve got his demo tape queued up after the break.
We love pocket instruments around here. If you prefer brass and woodwinds, this pocket woodwind MIDI controller just might draw your lips into an O.
The first two solutions that she submitted were rejected due to mathematical errors, but the third version won her the prize in 1816. However, due to the Academy policy of not allowing women to join (and to only attend events if they were wives of members), Germain was not able to attend the ceremony where the prize was granted. She was also not allowed to attend meetings of the Academy. After the Academy failed to publish her prize-winning work, 
