We’ve seen a lot of interest in LSM (LASER Scanning Microscopes) lately. [Stoppi71] uses an Arduino, a CD drive, and–of all things–two speakers in his build. The speakers are used to move the sample by very small amounts.
The speakers create motion in the X and Y axis depending on the voltage fed to them via a digital analog converter. [Stoppi71] claims this technique can produce motion in the micron range. His results seem to prove that out. You can see a video about the device, below.
We don’t know what cats see when they see a red laser beam, but we know it isn’t what we see. The reaction, at least for many cats — is instant and extreme. Of course, your cat expects you to quit your job and play with it on demand. While [fluxaxiom] wanted to comply, he also knew that no job would lead to no cat food. To resolve the dilemma, he built an automated cat laser. In addition to the laser module, the device uses a few servos and a microcontroller in a 3D printed case. You can see a video, below. Dogs apparently like it too, but of course they aren’t the reason it was built.
If you don’t have a 3D printer, you can still cobble something together. The microcontroller is an Adafruit Pro Trinket, which is essentially an Arduino Pro Mini with some extra pins and a USB port.
Remember that feeling when you first looked down on a microscope? Now you can re-live it but in slightly different way. [Venkes] came up with a way to make a Laser Scanning Microscope (LSM) with mostly off the shelf components that you probably have sitting around, collecting dust in your garage. He did it using some modified DVD pick-ups, an Arduino Uno, a laser and a LDR.
To be honest, there’s some more stuff involved in the making of the LSM but [Venkes] did a detailed Instructable explaining how everything fits together. You will need a fair dose of patience, it’s not very easy to get the focus right and it’s quite slow, an image takes about half an hour to complete, but it can do 1300x amplification at 65k pixels (256×256). From reading the instructions it seems that you will need a steady hand to assemble it together, some steps look kind of tricky. On the software side, the LSM uses Arduino and Processing. The Arduino part is responsible for the steering of the lens and taking the LDR readings. This information is then sent to Processing which takes care of interpreting the data and translate it to an image.
Pour yourself a nice hot cup of tea, because [iliasam]’s latest work on a laser rangefinder (in Russian, translated here) is a long and interesting read. The shorter version is that he got his hands on a broken laser security scanner, nearly completely reverse-engineered it, got it working again, put it on a Roomba that was able to map out his apartment, and then re-designed it to become a tripod-mounted, full-room 3D scanner. Wow.
The scanner in question has a spinning mirror and a laser time-of-flight ranger, and is designed to shut down machinery when people enter a “no-go” region. As built, it returns ranges along a horizontal plane — it’s a 2D scanner. The conversion to a 3D scanner meant adding another axis, and to do this with sufficient precision required flipping the rig on its side, salvaging the fantastic bearings from a VHS machine, and driving it all with the surprisingly common A4988 stepper driver and an Arduino. A program on a PC reads in the data, and the stepper moves another 0.36 degrees. The results speak for themselves.
This isn’t [iliasam]’s first laser-rangefinder project, naturally. We’ve previously featured his homemade parallax-based ranger for use on a mobile robot, which is equally impressive. What amazes us most about these builds is the near-professional quality of the results pulled off on a shoestring budget.
Ah, the holiday gingerbread house. A traditional — if tedious — treat; tasking to create, delicious to dismantle, so why not try applying some maker skills to making the job of building it easier? [William Osman] decided to try two unorthodox approaches to the gingerbread construct; first, he opted to build a gingerbread mobile home. Secondly, he cut the pieces out with a laser cutter.
After the tumultuous task of baking the gingerbread sheets, [Osman] modeled the trailer in SolidWorks and set to work cutting it out on his home-built, 80W laser cutter. Twice. Be sure to double check the home position on any laser cutting you do, lest you ruin your materials. Also — though this might be especially difficult when modelling food in any CAD programs — be sure to account for the thickness of your materials, otherwise you’ll end up with a lot of trimming on your hands. At least gingerbread cuts easily.
Hot glue and royal frosting secured the pieces together — as well as some improvisation of the final details — making for a picture perfect holiday scene — from a certain point of view.
It used to be pretty keen to stuff a radio receiver into an Altoid’s tin, or to whip up a tiny crystal receiver from a razor blade and a pencil stub. But Harvard researchers have far surpassed those achievements in miniaturization with a nano-scale FM receiver built from a hacked diamond.
As with all such research, the experiments in [Marko Lončar]’s lab are nowhere near as simple as the press release makes things sound. While it’s true that a two-atom cell is the minimal BOM for a detector, the device heard belting out a seasonal favorite from [Andy Williams] in the video below uses billions of nitrogen-vacancy (N-V) centers. N-V centers replace carbon atoms in the diamond crystal with nitrogen atoms; this causes a “vacancy” in the crystal lattice and lends photoluminescent properties to the diamond that are sensitive to microwaves. When pumped by a green laser, incident FM radio waves in the 2.8 GHz range are transduced into AM fluorescent signals that can be detected with a photodiode and amplifier.
The full paper has all the details, shows that the radio can survive extreme pressure and temperature regimes, and describes potential applications for the system. It’s far from a home-gamer’s hack at this point, but it’s a neat trick and one to watch for future exploitation. In the meantime, here’s an accidental FM radio with a pretty small footprint.
Space. The final frontier. Unfortunately, the vast majority of us are planet-locked until further notice. If you are dedicated hobbyist astronomer, you probably already have the rough positions of the planets memorized. But what if you want to know them exactly from the comfort of your room and educate yourself at the same time? [Shubham Paul] has gone the extra parsec to build a Real-Time Planet Tracker that calculates their locations using Kepler’s Laws with exacting precision.
An Arduino Mega provides the brains, while 3.5-turn-pan and 180-degree-tilt servos are the brawn. A potentiometer and switch allow for for planet and mode selection, while a GPS module and an optional MPU9250 gyroscope/magnetometer let it know where you are. Finally a laser pointer shows the planet’s location in a closed room. And then there’s code: a lot of code.
The hardware side of things — as [Shubham Paul] clarifies — looks a little unfinished because the focus of the project is the software with the intent to instruct. They have included all the code they wrote for the RTPT, providing a breakdown in each section for those who are looking to build their own.