Did you get a thermal printer when they were hot stuff, but then your interest cooled when you couldn’t decide what to do with it? Something similar happened to [Sunyecz22], and the poor printer sat unused until that magical day when the perfect use for it popped up — a random recipe receiver in the form of a toaster.
[Sunyecz22] was tired of searching for recipes every week before going to the grocery store. Between the millions of recipe options on the internet and the 1000-word essays that precede them all, the process was like a part-time job. Now all they have to do is push the little lever down and wait for a recipe to get toasted into some thermal paper. It doesn’t print the full recipe, only the essentials, and we love that. You get the name, the prep time, a rating, and a QR code that links to the recipe page.
This toaster runs on a Raspberry Pi Zero W that fetches recipes using the Spoonacular API and sends the deets to the printer. The lever makes use of some old pen springs to activate a limit switch and start the recipe-getting process. We think it would be extra cool if it stayed down until the recipe popped up. Butter your way past the break to see a short demo video.
We must say, this toaster is way more helpful than the talkie toaster from Red Dwarf.
Continue reading “Warm Up To Cooking With A Recipe-Randomizing Toaster”
For those unfamiliar with the term, a “Bitcoin Faucet” is usually used as an incentive in software that wants your attention. Complete a captcha or look at and advertisement and you get one millionth of a BTC, that sort of thing. You’re never going to get rich off of one of them, but most people aren’t going to turn down free money either. The latest project from [TJ Bruno] follows that same concept and brings it into the physical world. But you still aren’t going to get rich off of it.
The hardware used for this corporeal Bitcoin Faucet is pretty simple. All you need is a Raspberry Pi, a camera module, and a 2.8″ touch LCD. Naturally you could use a larger screen if you wanted, but then it wouldn’t fit inside of the very slick 3D printed stand that [TJ] developed. We might consider upgrading to a slightly speedier Pi though, in the demonstration video it looks like the Zero is struggling pretty hard to handle the GUI.
Using the Faucet is straightforward enough. You tap the screen and place a QR code representing your Bitcoin wallet on the device’s tray, where it’s scanned by the camera. In a few seconds the Faucet shows a QR code on its own screen that will point your phone’s browser to the transaction details so you can verify your digital coinage is on the way.
You might be wondering why you’d want to have a device that sits there waiting to pay out fractions of a BTC to anyone who’s willing to flash their wallet at it. We’re not entirely sure, though it might make for an interesting way to raise awareness about cryptocurrency. In this particular case though, [TJ] says he was just looking for a project that would give him an excuse to hone his Python skills. Nothing wrong with that around these parts.
Watching the growth of cryptocurrency from our unique vantage point, we can see how the hacker’s interest in Bitcoin as changed over the years. Where we once saw people excited about building custom mining rigs, we now see counters that tick down as the last coins are put into circulation. Looking at projects like this, it seems hackers are happy enough to just give the things away in an interesting way.
Since most people are carrying a camera-equipped computer in their pockets these days, QR codes can be a great way to easily share short snippets of information. You can put one on your business card so people can quickly access your contact information, or on your living room wall with your network’s SSID and encryption key. The design of QR codes also make them well suited to 3D printing, and thanks to a new web-based tool, you can generate your own custom STL in seconds.
Created by [Felix Stein], the website provides an easy to use interface for the many options possible with QR codes. Obviously you have full control over the actual content of the code, be it a simple URL or a something more specific like a pre-formatted SMS message. But you can also tweak physical parameters like size and thickness.
Once you’re happy with the 3D preview, you can have the website generate an STL for either single or multi-extrusion printers. For those of us who are puttering along with single extruder machines, you’ll need to swap the filament color at the appropriate layer manually. With so many variables involved, you’ll also need figure out which layer the swap should happen on your own.
Incidentally, this is an excellent example of where STL leaves something to be desired. When using a format like 3MF, color and material information could be baked right into the model. Once opened in a sufficiently modern slicer, all the tricky bits would automatically sorted out. Or at least, that’s what Prusa Research is hoping for.
We never really thought about it before, but a traditional barcode or QR code is pretty two dimensional. A 3D barcode sounds like marketing hype but the JAB (Just Another Barcode) system adds a third dimension in the form of color.
Traditional barcodes assume you have a pretty crude sensor, but a color camera now days is no big deal, so why not take advantage? The JAB system specifies two types of symbols: a master symbol and a slave symbol. A master symbol has four finder patterns at the corner. Slave symbols dock to a master or another docked slave.
If you want to create some JABs, there’s a web interface. If you check advanced, you can change the number of colors used, the size of each “module” (colored box), and the width and height of the master symbol. You can also arrange for error correction. The grid that shows the master and slave symbols will allow you to click on any dockable slave location to create more symbols with different attributes.
You can then save the JAB image and use the scan menu item (at the top) to read the code back. It will also read from a camera.
If you are using a color camera and a computer or phone to read barcodes, this probably is something to check out. After all, you are acquiring color data, why not use it?
You might think of the barcode as something modern, but it has a long strange history going back to the 1930s. Early barcodes looked like bullseyes and were actually inspired by Morse code. We wonder how one of these would look on someone’s arm in ink?
We should all be familiar with QR codes, those blocky printed patterns containing encoded text, URLs, or other data. A few years ago they were subject to their own cloud of hype, but now they have settled down in their niche of providing a handy route for a smartphone owner to reach a website without having to type an address.
Have you ever wondered how they work? There are plenty of dry technical guides out there, but if they’re not your thing you might find [Nayuki]’s step-by-step guide to be of interest. It explains the encoding and error checking bit generation process before starting on the familiar three-squares pattern and timing bars of the QR code itself. The really interesting part comes with its explanation of overlays, a set of repeating patterns that are added to the final data segment, and how the pattern used is chosen to minimise penalties due to large blocks of the same colour in the final piece. The chances are most of us will never have to create a QR code from scratch, but it is this type of fascinating technical general knowledge that makes guides like this such an interesting read.
QR codes have appeared in quite a few projects here over the years, but the one we find particularly amusing is this project to hack them by changing one QR into another.
Via Hacker News.
If the booths at CES are to be believed, the future is full of home robots: everything from humanoid robots on wheels to Alexas duct taped to a Roomba. Back in reality, home robots really aren’t a thing yet. There’s an obvious reason for this: getting around a house is hard. A robot might actually need legs to get up and down stairs, and GPS simply doesn’t exist indoors, at least to the accuracy needed. How on Earth does a robot even navigate indoors?
This project for the Hackaday Prize solves the problem of indoor navigation, and it does it in an amazingly clever way. This is using QR codes for navigation, but not just any QR codes. They’re QR codes read by an infrared camera, and painted on the walls and ceilings with a special IR sensitive paint that’s invisible to the human eye. It’s navigation for robotic vision, and it’s a fantastic idea.
The basic idea behind this project is to use an IR camera — or basically any webcam with the IR blocking filter removed — and a massive amount of IR LEDs to illuminate any target. So far, the proof of concept works. A computer can easily read QR codes, and if paint is invisible to the human eye but visible to an IR camera, the entire project is merely a matter of implementation.
There have been a number of projects that try to add indoor navigation to robots. Some of them use LIDAR, some use computer vision and SLAM. These are computationally expensive. Some even use wireless beacons to navigate indoors like the SubPos Ranger from the 2016 Hackaday Prize. Using IR and QR codes is just so simple and hacker-friendly, and we think it’s fantastic.
QR codes are easy to produce, resistant to damage, and can hold a considerable amount of data. But generally speaking, eating them has no practical purpose. Unfortunately the human digestive tract lacks the ability to interpret barcodes, 2D or otherwise. But thanks to the University of Copenhagen, that may soon change.
A new paper featured in the International Journal of Pharmaceutics details research being done to print QR codes with ink that contains medicine. The mixture of medicines in the ink can be tailored to each individual patient, and the QR code itself can contain information about who the drugs were mixed for. With a standard QR reader application on their smartphone, nurses and care givers can scan the medicine itself and know they are giving it to the right person; cutting down the risk of giving patients the wrong medication.
The process involves using a specialized inkjet printer to deposit the medicine-infused ink on a white edible substrate. In testing, the substrate held up to rough handling and harsh conditions while still keeping the QR code legible; an important test if this technology is to make the leap from research laboratory to real-world hospitals.
In the future the researchers hope the edible substrate can be produced and sent to medical centers, and that the medicinal ink itself will be printable on standard inkjet printers. If different medicines were loaded into the printer as different colors, it should even be possible to mix customized drug “cocktails” through software. Like many research projects it seems likely the real-world application of the technology won’t be as easy as the researchers hope, but it’s a fascinating take on the traditional method of dispersing medication.
QR codes have long been a favorite of the hacker community. From recovering data from partial codes to using them to tunnel TCP/IP, we’ve seen our fair share of QR hacks over the years.
[Thanks to Qes for the tip]
Continue reading “Eating A QR Code May Save Your Life Someday”