It may not exactly be what [Princess Leia] used to beg [Obi-Wan] for help, but this Star Wars-inspired volumetric display is still a pretty cool hack, and with plenty of extra points for style.
In some ways, [Maker Mac]’s design is a bit like a 3D printer for images, in that it displays slices of a solid model onto closely spaced planar surfaces. Sounds simple enough, but there are a lot of clever details in this build. The main component is a lightly modified LCD projector, a DLP-based machine with an RGB color wheel. By removing the color wheel from the projector’s optical path and hooking its sync sensor up to the control electronics, [Mac] is able to increase the framerate of the display, at the cost of color, of course. Other optical elements include a mirror to direct the projected images upwards, and a shutter harvested from an old pair of 3D TV glasses. Continue reading “A Volumetric Display With A Star Wars Look And Feel”→
Radio trackers have become an important part of studying the movements of wildlife, but keeping one running for the life of an animal has been challenging. Researchers have now developed a way to let wildlife recharge trackers via their movements.
With trackers limited to less than 5% of an animal’s total mass to prevent limitations to the their movement, it can be especially difficult to fit trackers with an appropriately-sized battery pack to last a lifetime. Some trackers have been fitted with solar cells, but besides issues with robustness, many animals are nocturnal or live in dimly-lit spaces making this solution less than ideal. Previous experiments with kinetically-charged trackers were quite bulky.
The Kinefox wildlife tracking system uses an 18 g, Kinetron MSG32 kinetic energy harvesting mechanism to power the GPS and accelerometer. Similar to the mechanical systems found in automatic winding watches, this energy harvester uses a pendulum glued to a ferromagnetic ring which generates power as it moves around a copper coil. Power is stored in a Li-ion capacitor rated for 20,000 charge/discharge cycles to ensure better longevity than would be afforded by a Li-ion battery. Data is transmitted via Sigfox to a cloud-based database for easy access.
If you want to build one to track your own pets, the files and BOM are available on GitHub. We’ve featured other animal trackers before for cats and dogs which are probably also applicable to bison.
[Hack Club] is a nonprofit network of coder and maker clubs for teenage high school students around the world. With an impressive reach boasting clubs in about 400 schools, they serve approximately 10,000 students. Their OnBoard program asserts, “Circuit boards are magical. You design one, we’ll print it!”
Any teenage high school student can apply for a [Hack Club] OnBoard Grant to have their Printed Circuit Board design fabricated into real hardware. The process starts by designing a PCB using any tool that can generate Gerber files. The student then publishes their design on GitHub and submits the Gerber files to a PCB manufacturer.
A screenshot from the board house showing the completed design upload and production cost is the main requirement of the grant application. If approved, the grant provides up to $100 to cover PCB manufacturing costs.
OnBoard encourages collaboration, community, and friends. Designers can share their projects and progress with [Hack Club] teens around the world. Those who are working on, or have completed, their own circuit board designs can share support and encouragement with their peers.
Example hardware projects from [Hack Club] include Sprig, an open-source handheld game console based on the Raspberry Pi Pico microcontroller. Teen makers can explore the example OnBoard projects and then it’s… three, two, one, go!
While most countries have switched to digital broadcasting, and most broadcasts themselves have programming on 24/7 now, it’s hard to remember the ancient times of analog broadcasts that would eventually stop sometime late at night, displaying a test pattern instead of infomercials or reruns of an old sitcom. They were useful for various technical reasons including calibrating the analog signals. Some test patterns were simply camera feeds of physical cards, but if you wanted the most accurate and reliable test patterns you’d need a Philips pattern generator which created the pattern with hardware instead, and you can build your own now because the designs for these devices were recently open-sourced. Continue reading “Recreating An Analog TV Test Pattern”→
When you first start out in the PCB layout game and know just enough to be dangerous, you simply plop down a connector, run a trace or two, and call it a hack. As you learn more about the finer points of inconveniencing electrons, dipping toes into the waters of higher performance, little details like via size, count, ground plane cutouts, and all that jazz start to matter, and it’s very easy to get yourself in quite a pickle trying to decide what is needed to just exceed the specifications (or worse, how to make it ‘the best.’) Connector terminations are one of those things that get overlooked until the MHz become GHz. Luckily for us, [Rob Ruark] is on hand to give us a leg-up on how to get decent performance from edge-launch SMA connections for RF applications. These principles should also hold up for high-speed digital connections, so it’s not just an analog game.
[Carl] explores all manner of optimizations to his flippy actuators in the video. He tried making them oscillate faster by putting a hole in the middle to reduce drag. Other tricks include getting the arm thickness just right, and experimenting with rigidity through adding or removing sections of soldermask.
Fundamentally, though, he learned the key to longevity laid in the copper traces on the flex PCBs themselves. After enough flexural cycles, the traces would fail, killing the actuator. He experimented with a variety of solutions, eventually devleoping a ruggedized two-arm version of his actuator. Twenty samples were put to the test, oscillating at 25 Hz for two weeks straight. All samples survived the test, in which they were put through around 107,820,000 cycles.
[Carl] has put in plenty of hard work on this project, and his actuators have come a long way since we saw them last. He hopes to use the better actuators to improve his FlexLED display. Video after the break.
Setting up an electronics work area is a highly personal and situational affair, with many interesting problems to be solved, and for many of us, significant budget constraints. The requirements for electronics development vary wildly depending upon the sort of work to be undertaken, but there is core equipment that many of us would consider a bare minimum for usability. [Badar Jahangir Kayani] is at the start of his career as an electrical engineer, and has documented the kitting out of his personal work areas for others to learn from.
A place for everything, everything in its place
As we already touched upon, the cost is often the main driving factor determining what we end up with, and this cost-vs-performance/quality tradeoff is what makes some of us fret over a buying decision. Buying secondhand off eBay is an option, but a lack of warranty and the unknowable condition are not great selling points.
[Badar] has a good grasp of the basic concepts of usability, such as keeping the most frequently used tools, instruments, and components out in the open. Less frequently used stuff is stored in drawers, bins, and compartment boxes. Buying the same storage systems keeps things as consistent as much as possible since it makes storing them easier. We were particularly interested in the use of the cloud-based database solution, Airtable used to create a parts database for minimal outlay.
Oooh! Cable tray action
There is also a lot of detail about how to walk that cost/quality/performance tightrope and get the best-valued gear currently on the market. Some notable examples are the UNI-T UT61E Digital Multimeter for general test use, the Controleo3 reflow controller for SMT assembly, and the Omnifixo OF-M4 magnetic fixament kit for that fiddly wiring part. [Badar] also recommends the FumeClear Solder Fume Extractor, although they lament that particular bit of kit is still under evaluation.
Obviously, we’ve talked about work areas a lot on these pages, like this time. For those with more space, this flippin’ awesome bench will be of interest, and if space is tight (or travel is a regular thing) might we suggest this 3D printed DIN-rail mounting cube as a starting point?
