Since the high-definition era, screens with many millions of pixels have become commonplace. Resolutions have soared into the stratosphere, and media has never looked clearer or crisper. However, [gatoninja236] decided to go the other way with this build – an LED matrix capable of playing Youtube videos.
The execution is simple. A Raspberry Pi 3, with the help of a Python script, downloads a Youtube video. It then runs this through OpenCV, which parses the video frames, downconverting them to suit a 64×64 pixel display. Then, it’s a simple matter of clocking out the data to the 64×64 RGB LED matrix attached to the Raspberry Pi’s IO pins, where the video is displayed in all its low-resolution glory.
Is it a particularly useful project? No. That doesn’t mean it’s not without value however; it teaches useful skills in both working with LED displays and video data scraped from the Internet. If you simply must have more pixels, though, this ping pong video wall might be more to your liking. Video after the break.
Continue reading “Playing Youtube Videos At Incredibly Low Resolution On LEDs”
[Mister M] was quite excited to mess around with the new high-quality Raspberry Pi camera and build a project around it. Unfortunately, lockdown forced him to rummage through old tech on hand rather than hunting down a fresh eye-catching enclosure out in the wild. We spent many hours playing with one of these Merlin toys whenever six AA batteries could be spared to feed the matrix of hungry 1970s LEDs, so we would argue that [Mister M] should explore his personal stores more often.
Before we forget — it’s cool; this one was already broken. The Merlin Pi camera’s wizardry works on two levels — [Mister M] can take still pictures and record video through the GUI he built for the touchscreen, or go retro and use the little push buttons nestled in the Merlin control panel. [Mister M] worked a Dropbox uploader into the GUI, so he doesn’t have to worry about filling up the SD card with backyard bird movies in the middle of filming them.
[Mister M] says he accidentally warped the Merlin’s battery cover while trying to soak away the sticker and had to use a piece of acrylic. Although it’s unfortunate, we think it may have been for the better given the huge hole necessitated by the camera lens. Check out the build video after the break.
If you hadn’t heard about this beefy new camera module until now, our own [Jenny List] brought it into focus a couple months back and more recently had a go at hacking with it herself.
Continue reading “Merlin Pi Camera Is A Photographic Wizard”
When the world is on your shoulders, it can be relaxing to remember that we’re just hairless monkeys hurtling through space on a big rock alongside a lot of other rocks. If you find yourself wondering where exactly the other major rocks are instead of worrying, we think that’s a good sign.
Wherever [snowbiscuit] lives, there’s a large planet finder in a public square somewhere that stopped locating rocks a long time ago. Hungry to watch such a thing in action, [snowbiscuit] built a great-looking tabletop version that uses the Horizontal Coordinate System to locate planets. Inside is a Raspberry Pi 3, which queries NASA for azimuth and altitude data and combines that data with a predetermined north reading to point out whatever planet was selected by spinning the printed telescope on top. The telescope itself is non-working, and returns to north after a few seconds to wait for input.
This project is wide open for remixing if you want to make your own. As lovely as it is now, designing around a slip ring would eliminate all those long wires and make it more sleek. Take a peek after the break.
Don’t stop your desktop space toy collection there — build an ISS-tracking lamp to go with it.
Continue reading “Automatic Planet Finder Is Out Of This World”
It happens to everyone. You get your hands on an Etch-A-Sketch for the first time, and armed with the knowledge of how it works, you’re sure you can draw things other than rectangles and staircases. And then you find out the awful truth: you are not as precise as you think you are, and if you’re [QuintBUILDS], the circles you try to draw look like lemons, potatoes, or microbes.
Okay, yes, this definitely isn’t the first CNC-ified Etch-A-Sketch we’ve seen, but it just might be the coolest one. It’s certainly the most kid-friendly, anyway.
Most importantly, you can still pick it up and shake it to clear the screen, a feature sorely lacking in many of the auto-sketchers we scratch about. And if you’re not fully satisfied by this hack, be sure to check out the stop-motion video after the break that turns this baby into a touch-screen video player for Flatlanders.
Turn it over and you’ll find a Raspberry Pi 3 and a CNC hat. The knobs are belt-driven from a pair of NEMA-17 size stepper motors that interface to the knobs with tight-fitting pulleys. Power comes from four 18650s, and is metered by a battery management board that provides both overcharge and drain protection. At some point in the future, [QuintBUILDS] plans to move to a battery pack, because the cell holder is electrically unstable.
We love the welded frame and acrylic enclosure because they make the thing sturdy and portable. Also, we’re suckers for see-through enclosures. They’re clearly superior if you want to do what [QuintBUILDS] did and take it to an elementary school science fair to show the kids just how cool science can be if you stick with it.
If you don’t think motorized Etch-A-Sketches can be useful, maybe you just haven’t seen this clock build yet.
Continue reading “CNC Etch-A-Sketch: Stop Motion Is Logical Next Step”
On paper, pet doors are pretty great. You don’t have to keep letting the cat in and out, and there should be fewer scratches on the door overall. Unfortunately, your average pet door is indiscriminate, and will let any old creature waltz right in. Well, [Jeremiah] was tired of uninvited critters, so he built a motorized door with a built-in bouncer. Now, only animals with pre-approved BLE tags can get in.
The bouncer is a Raspi 3 running Node-RED, which scans continuously for BLE advertisements from the cats’ collars. [Jeremiah] settled on Tile tags because they’re reliable and cat-proof. The first version used an Arduino and RFID tags for the cats, but they had to get too close to the door to trigger it.
We love [Jeremiah]’s choice of door actuator, a 12V retractable car antenna. [Jeremiah] uses the antenna itself to lift and lower the removable lockout panel that comes with the door. He removed the circuit that retracts the antenna when power is lost, so that power outages don’t become free-for-alls for shelter-seeking animals.
There’s also a nice feature for slow creatures—the door won’t close until 15 seconds after the last BLE ad, so they cats won’t ever have to Indiana Jones it through the opening. Magnetic switches currently limit the door travel at the top and bottom, though [Jeremiah] will eventually replace them with standard switches. Paw at the break until you get a walk-through video.
Cats will be cats, and the ones that go outside will probably rack up a body count. Here’s a cat door that looks for victims clenched between cat jaws and starts a 15-minute lockout period.
Continue reading “Over-Engineered Cat Door Makes Purrfect Sense”
No, you aren’t looking at a 30 year old Teac graphic equalizer that somebody modified. The MWA-002 Network Music Player created by [GuzziGuy] is built entirely from new components, and easily ranks up there with some of the most gorgeous pieces of homebrew audio gear we’ve ever seen. Combining modular hardware with modern manufacturing techniques, this 1980s inspired build is a testament to how far we’ve come in terms of what’s possible for the dedicated hacker and maker.
The enclosure, though it looks all the world like a repurposed piece of vintage hardware, was built with the help of a CNC router. It’s constructed from pieces of solid oak, plywood, and veneered MDF that have all been meticulously routed out and cut. Even the front panel text was engraved with the CNC and then filled in with black paint to make the letters pop.
Internally, the MWA-002 is powered by a Raspberry Pi 3 running Mopidy to play both local tracks and streaming audio. Not satisfied with the Pi’s built-in capabilities, [GuzziGuy] is using a Behringer UCA202 to produce CD-quality audio, which is then fed into a TPA3116 amplifier. In turn, the output from the amplifier is terminated in a set of female jacks on the player. Just like the stereo equipment of yore, this player is designed to be connected to a larger audio system and doesn’t have any internal speakers.
The primary display is a 256×64 Futaba GP1212A02A FVD which has that era-appropriate glow while still delivering modern features. [GuzziGuy] says it was more difficult to interface with this I2C display than the LCDs he used in the past due to the lack of available libraries, but we think the final product is proof it was worth the effort. He bought both the VFD spectrum analyzer and LED VU meter as turn-key modules, but the center equalizer controls are completely custom; with dual MCP3008 ADCs to read the state of the sliders and the Linux Audio Developer’s Simple Plugin API (LADSPA) to tweak the Pi’s audio output accordingly.
We’re no strangers to beautiful pieces of audio gear here at Hackaday, but generally speaking, most projects involve modernizing or augmenting an existing device. While those projects are to be admired, the engineering that goes into creating something of this caliber from modular components and raw building materials is really an accomplishment on a whole different level.
When installing almost any kind of radio gear, the three factors that matter most are the same as in real estate: location, location, location. An unobstructed location at the highest possible elevation gives the antenna the furthest radio horizon as well as the biggest bang for the installation buck. But remote installations create problems, too, particularly with maintenance, which can be a chore.
So when [tsimota] got a chance to relocate one of his Automatic Dependent Surveillance-Broadcast (ADS-B) receivers to a remote site, he made sure the remote gear was as bulletproof as possible. In a detailed write up with a ton of pictures, [tsimota] shows the impressive amount of effort he put into the build.
The system has a Raspberry Pi 3 with solid-state drive running the ADS-B software, a powered USB hub for three separate RTL-SDR dongles for various aircraft monitoring channels, a remote FlightAware dongle to monitor ADS-B, and both internal and external temperature sensors. Everything is snuggled into a weatherproof case that has filtered ventilation fans to keep things cool, and even sports a magnetic reed tamper switch to let him know if the box is opened. An LTE modem pipes the data back to the Inter, a GSM-controlled outlet allows remote reboots, and a UPS keeps the whole thing running if the power blips atop the 15-m building the system now lives on.
Nobody appreciates a quality remote installation as much as we do, and this is a great example of doing it right. Our only quibble would be the use of a breadboard for the sensors, but in a low-vibration location, it should work fine. If you’ve got the itch to build an ADS-B ground station but don’t want to jump in with both feet quite yet, this beginner’s guide from a few years back is a great place to start.