For a long time it seemed like e-ink displays were outside the reach of us lowly hackers, as beyond the handful of repurposed Kindles that graced these pages, we saw precious few projects utilizing this relatively exotic display. But that’s changed over the last couple of years, and we’re thrilled to start seeing hackers bend this incredible technology to their will.
A perfect example is PaperLedger, an entry into the 2019 Hackaday Prize by [AIFanatic]. This wireless device is designed to display the current price of various cryptocurrencies on its 2.9-inch e-ink screen and provide audible price alerts with its built-in speaker. It even has a web portal where users can configure the hardware or view more in-depth price information.
The PaperLedger is based on the TTGO T5 V2.2 ESP32, but it looks like [AIFanatic] is in the process of spinning up a new board for the MIT licensed project to address some nagging issues for this particular application. Unfortunately, it doesn’t look like there are any pictures of the new board yet, but a description of the changes on the Hackaday.IO page shows that most of the work seems to be going into improving support for running on batteries.
Even if you’re not interested in cryptocurrency, the PaperLedger looks like a fantastic little e-ink monitor for pretty much anything else you’d like to keep a close eye on. The GPLv3 licensed firmware is available on the project’s GitHub page, so expanding or completely changing the device’s functionality shouldn’t be too tricky for anyone with a desire to do so and a working knowledge of C++.
We’ve seen several projects using the various TTGO boards that mate an ESP32 with a display at this point, and it looks like a great platform to check out if you want to push some data to a little WiFi screen with the minimum amount of hassle.
If there’s one thing any cat will work for, it’s food. Usually, this just consists of meowing and/or standing on your chest until you give up the goods. [DynamicallyInvokable] has a beautiful cat, Emma, who meows loudly for food at obscene hours of the morning. As she ages, it’s getting harder and more important to control her weight. Clearly, it was time to build the ultimate automatic cat feeder—one that allows him to get lazy while at the same time getting smart about Emma’s weight.
After a year and a half of work, the feeder is complete. Not only does it deliver the goods several times a day, it sends a heap of data to the cloud about Emma’s eating habits. There’s a scale built into the platform, and another in the food bowl. Together, they provide metrics galore that get automatically uploaded to AWS. Everything is controlled with an ESP32 Arduino, including a rainbow of WS2812s that chases its tail around the base of the feeder. The faster it goes, the closer it is to feeding time.
The best part about this unique feeder is that nearly every piece is 3D printed, including the gears. Be sure to check out the build gallery, where you can watch it come together piece by piece. Oh, and claw your way past the break to see Emma get fed.
Emma doesn’t have to worry about sharing her food. If she did, maybe [DynamicallyInvokable] could use facial recognition to meet the needs of multiple cats.
Continue reading “Cat Feeder Adds Metrics To Meow Mix”
Hackaday Editors Elliot Williams and Mike Szczys geek out over the latest hacks. This week we saw a couple of clever CNC builds that leverage a great ESP32 port of GRBL. The lemonade-pitcher-based submarine project is everything you thought couldn’t work in an underwater ROV. Amazon’s newest Dot has its warranty voided to show off what 22 pounds gets you these days. And there’s a great tutorial on debugging circuits that grew out of a Fail of the Week. Plus, we get the wind knocked out of us with an ambitious launch schedule for airless automotive tires, and commiserate over the confusing world of USB-C.
Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!
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Continue reading “Hackaday Podcast 029: Your Face In Silver Sand, Tires Of The Future, ESP32 All The CNC Things, And Sub In A Jug”
Taking a selfie before the modern smartphone era was a true endeavor. Flip phones didn’t have forward-facing cameras, and if you want to go really far back to the days of film cameras, you needed to set a timer on your camera and hope, or get a physical remote shutter. You could also try and create a self portrait on an Etch a Sketch, too, but this would take a lot of time and artistic skill. Luckily in the modern world, we can bring some of this old technology into the future and add a robot to create interesting retro selfies – without needing to be an artist.
The device from [im-pro] attaches two servos to the Etch a Sketch knobs. This isn’t really a new idea in itself, but the device also includes a front-facing camera, taking advantage of particularly inexpensive ESP32 Camera modules. Combining the camera features with [Bart Dring]’s ESP32 Grbl port is a winner. Check the code in [im-pro]’s GitHub.
Once the picture is taken, the ESP32 at the heart of the build handles the image processing and then drawing the image on the Etch a Sketch. The robot needs a black and white image to draw, and an algorithm for doing it without “lifting” the drawing tool, and these tasks stretch the capabilities of such a small processor. It takes some time to work, but in the end the results speak for themselves.
The final project is definitely worth looking for, if not for the interesting ESP32-controlled robot than for the image processing algorithim implementation. The ESP32 is a truly versatile platform, though, and is useful for building almost anything.
Continue reading “Etch-A-Selfie”
Pen plotters, those mechanical X-Y drawing machines that have in many cases been superseded by inkjet and other printer technologies, exert a fascination from a section of our community. Both analogue and digital machines are brought out of retirement for some impressive graphical effects, and we suspect that more than one of you wishes you had the space for one in your lives.
The good news is that you now no longer need room for a hefty piece of 1970s instrumentation, because the ever-inventive [Bart Dring] has produced a tiny 3D-printed plotter with an ESP32 at its heart. The ESP runs his ESP32 port of the Grbl firmware, and can handle a G-code file placed wirelessly upon the controller’s SD card.
The mechanism is particularly clever, using a single belt for both X and Y axes. The pen lift Z axis is a hinged design rather than a linear one, with a hobby servo doing the lifting. The hinge bearings are placed as close as possible to the paper surface to achieve an approximation to a vertical lift. You can see the machine in action in the video below the break, drawing its own self-portrait.
If you are a long-time reader you will recognise [Bart]’s work, he has appeared here quite a few times. His coaster-cutting machine and his CNC plotter badge are particularly memorable.
Continue reading “Lack Of Space Is No Longer An Excuse For Not Having A Pen Plotter”
In an ideal world, shop space, tools, and components would be free. But until we get to that Star Trek utopia, hackerspaces will have to rely on donations from the community to help stay afloat. While asking for money, at least you can have some fun with it if you design and build an Internet-connected donation box.
Or at least that’s how [Goran Mahovlic] handled it for the Radiona hackerspace in Zagreb, Croatia. Not content with just cutting a slit in the top of a shoe box, he came up with a physical donation system that’s not only more informative for those donating, but more organized for those collecting the funds.
The key is a arcade-style programmable coin acceptor from SparkFun. When connected to a microcontroller, this allows the box to keep a running tally on how much money has been inserted. With the use of a RFM96 LoRa module, it can even report on the current haul while remaining mobile; perfect for when the hackerspace has events outside of their home base.
But counting quarters is hardly a task befitting a powerful microcontroller like the ESP32. So [Goran] gave the chip something to do in its spare time by adding a couple of buttons and an LCD. This allows the user to scroll through a list of various projects that are looking for donations, and decide which one they want to financially support. When the donation box counts how much money has been inserted, it records which project its been earmarked for.
Of course, if you’d rather the free market do its thing, we’ve seen this same coin acceptor used to build a locker-sized vending machine. Or if you’re feeling crafty, you could always try your hand at building one with cardboard.
Continue reading “High-Tech Alms Collection With The ESP32”
If you read Hackaday on a regular basis, there are some names you will have seen more than once. People who continually produce fascinating and inventive projects that amaze and delight us, and who always keep us coming back for more. One such hacker is [Jeroen Domburg], perhaps better known in these pages by the handle [Sprite_TM], who has never failed to delight us in this respect.
Today is a special day for [Jeroen] for it is his wedding day, and his friend [Maarten Tromp] has decided to surprise him and his wife [Mingming] with a special gift. At first sight it is simply a pair of blinky badges in the shape of a bride and groom, but closer examination reveals much more. The PCBs are studded with WS2812 addressable LEDs controlled by an ESP32 module and powered by a small LiPo battery, and the clever part lies in the software. The two badges communicate via Bluetooth, allowing them to both synchronise their flashing and flash ever faster as the couple come closer to each other.
The write-up is an interesting tale of the tribulations of designing a badge, from which we take away that buying cheap LEDs may be a false economy. A surprise was that the black-cased and white-cased versions of the LEDs had different timings, and they proved prone to failure.
We wish the happy couple all the best, thank [Sprite_TM] for all he has given us over the years, and look forward to seeing his future projects.