[Rene Strange] has graced these fair pages a short while ago with a sweet Raspberry Pi software based poly synth, with a tantalising reference to it being a bare metal application. So now, we’ll look into circle, the bare metal programming environment that it is based upon. The platform consists of a large set of C++ classes to access the hardware as well as perform tasks such as task creation and scheduling in the cooperative multitasking, multicore environment. Supporting all Raspberry Pi boards from version 2 onwards (not including the Pico!) in both 32-bit and 64-bit flavours, the environment is pretty complete. Classes are provided for USB, networking, FatFS, as well as more mundane tasks such as dealing with interrupts. On top of these classes there are a pile of application-specific libraries, covering functions such as display interfacing, GUIs using a variety of frameworks, and some more esoteric applications such as interfacing to a Pico, and even sending the system log to a remote web browser!
Classes and libraries however, don’t always help by themselves, which is where the 42 (yes, we know) code examples come in very handy. They’ve provided example applications for some fun stuff like drawing Mandelbrot fractals to the display, as well as some more mundane tasks that we have to deal with such as getting that pesky DMA controller to play nice with the SPI hardware. All-in-all, this looks like a great set of tools for taking full advantage of some fairly beefy hardware for your next embedded project that needs plenty of resources, but not all that unnecessary operating system stuff.
Perhaps not quite as complete as circle, but we’ve seen a fair few Raspberry Pi Bare metal projects over the years, like the Nerdsynth, based on the PiZero, and this neat little bare metal assembly language clone of starfox.
Thanks [Ruhan] for the tip!
Header: Aryan Patidar, CC BY 4.0/Evan-Amos, Public domain.
The Mekamon from Reach Robotics is a neat thing, a robot controlled by a phone app that walks on four legs. [Wes Freeman] decided to hack the platform, giving it a sensor package and enabling some basic autonomous behaviours in the process.
[Wes] started out by using a packet sniffer to figure out the command system for controlling the Mekamon robot over Bluetooth. Then, he set about fitting a Raspberry Pi 3 on the ‘bot, along with a Pi Camera on a gimballed camera head.
Running OpenCV on the Raspberry Pi gives the Mekamon robot the ability to follow a colored ball placed in its field of vision. Later work involved upgrading the hardware to a Pi Compute Module 3, with its dual camera inputs allowing for the use of a stereo imaging setup.
All the parts simply ziptie on top of the original robot, with no permanent changes needed. It’s a neat way of hacking, by expanding the original capabilities without actually having to tamper within.
We’ve seen plenty of autonomous builds over the years, from farming robots to those designed to explore the urban environment. Video after the break.
Continue reading “Hacking The Mekamon Robot To Add New Capabilities”
When you need quick answers to life’s burning yes or no questions, most reasonable people reach for a Magic 8-Ball. But since we all have most of those answers memorized at this point, has the Magic 8-Ball sunk to a cliche and become less useful in the present day?
Signs point to yes. Yeah, maybe.
Not to worry, because [DJ Harrigan] has given the Magic 8-Ball a modern makeover by redesigning it to serve up suitable GIFs instead. Inside that beautifully-engineered snap-together shell lives a Raspberry Pi 3, and it displays the GIFs on a 240 x 240 IPS LCD screen. [DJ] wanted to use a round screen, but couldn’t find one with a good enough refresh rate. Maybe someday. We love this build either way.
Our favorite part is probably the power button, which is incorporated as the period in the ‘.gif’ logo. Although it takes a bit longer to get this 8-Ball ready to answer questions, it’s worth the wait. And besides, the splash screen is nice.
Once it’s booted up and ready to go, you still have to shake it — for this, [DJ] used a simple DIY spring-based tilt switch. Check out the demo and build video after the break. If you want to build one for yourself, the files are up on the project site.
Need decision-making support on the go? This Magic 8-Ball business card should fit in your wallet.
Continue reading “Shake Up Your Magic 8-Ball With GIFs”
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”