Wireless, Low Power E-Ink Weather Gadget

March 2, 2021 by Donald Papp 14 Comments

Not that long ago, making a low-power and wireless weather display complete with an e-ink screen would have required a lot of work and almost certainly would have been larger than the device [Dmitry] created.

(1) Weather alert indicator, (2) Current temperature, (3) Humidity and wind, (4) 24-hour temperature graph, (5) 24-hour precipitation probably graph

His low power e-ink weather gadget takes advantage of one of the niftier developer boards out there to create a useful and slim device that does exactly what he needs and not a lick more. It’s fast to look up weather online, but not as fast as glancing at a display in a convenient location.

The board [Dmitry] selected is a LilyGO TTGO T5s, an ESP32-based board that integrates an e-ink display, which requires no power unless being updated. It has been loaded with just enough smarts to fetch weather information using the OpenWeather API, and update the display accordingly.

Powering up the WiFi to fetch an easily-parsed JSON file and update the display only once per hour means that a battery can provide months of runtime. As a bonus, the LilyGO board even includes the ability to charge the battery, making things awfully convenient.

The bill of materials is here and code for the device, including setup directions, is on the project’s GitHub repository. And if your tastes happen to run more towards the artistic than utilitarian, we have just the weather display for you.

Micro:bit Makes Cardboard Pinball More Legit

February 24, 2021 by Kristina Panos 2 Comments

What have you been doing to ward off the winter blues? [TechnoChic] decided to lean in to winter and make a really fun-looking game out of it by combining the awesome PinBox 3000 cardboard pinball sandbox with a couple of Micro:bits to handle and display the player’s score. Check it out the build and gameplay in the video after the break.

The story of Planet Winter is a bittersweet tale: basically, a bunch of penguins got tired of climate change and left Earth en masse for a penguin paradise where it’s a winter wonderland all year round. There’s a party igloo with disco lights and everything.

[TechnoChic] used a Micro:bit plugged into a Brown Dog Gadgets board to keep track of scoring, control the servo that kicks the ball back out of the igloo, and run the blinkenlights. It sends score updates over Bluetooth to a second Micro:bit and a Pimoroni Scrollbit display that sit opposite the pinball launcher. She went through a few switch iterations before settling on conductive maker tape and isolating the ball so it only contacts the tape tracks.

There are two ways to score on Planet Winter — the blizzard at the end of the ball launcher path nets you ten points, and getting the ball in the party igloo is good for thirty. Be careful on the icy lake in the middle of the playfield, because if the ball falls through the ice, it’s gone for good, along with your points. It’s okay, though, because both the party igloo and the ice hole trigger an avalanche which releases another ball.

Seriously, these PinBox 3000 kits are probably the most fun you can have with cardboard, even fresh out of the box. They are super fun even if you only build the kit and make a bunch of temporary targets to test gameplay, but never settle on a theme (ask us how we know). Not convinced? Hackaday Editor-in-Chief [Mike Szczys] explored them in depth at Maker Faire in 2018.

Continue reading “Micro:bit Makes Cardboard Pinball More Legit” →

Useful Build Tips For Making LED Panel Frames

February 23, 2021 by Donald Papp 9 Comments

[NotLikeALeafOnTheWind] has created many LED-based display projects, and shares his method for making attractive LED panel frames and mounts. At first glance it may look as though slapping a rectangle of aluminum extrusion around a display is all it takes, there is also the mounting and management of wiring, power supply, and possibly a Raspberry Pi to deal with. The process of building an attractive frame also has a few hidden gotchas that can be avoided with a bit of careful planning.

Magnetic feet on the LED panels makes mounting much easier and more flexible.

Here is one tip that will resonate with some readers: don’t rely on specified dimensions of parts; measure the actual parts yourself. There can be small differences between what a data sheet says to expect, and the dimensions of the actual part in one’s hands. It may not be much, but it can be the difference between an ideal fit, and something that looks like a bit of a hack job.

[NotLikeALeafOnTheWind] provides some basic frame layouts, and suggests using two- or three-channel extrusions to provide a flat bezel around the display edge if desired. Mounting the LED panel itself is done with magnetic feet and providing a length of steel bar to which the display can attach. This can provide a flush mount while avoiding the whole issue of screw-mounting the display panels themselves, or sliding them into channels. For mounting all the other hardware, a piece of DIN rail and some 3D-printed parts takes care of that.

The result looks slick and sturdy, and some of the tips are sure to be useful even if the whole process isn’t applied. We like the way the basic design scales and is flexible about the thickness and size of the LED panels themselves, making it a promising way to accommodate perfectly functional oddball panels that end up in the trash.

DIY Bread Slice Paper Goes Against The Grain

February 17, 2021 by Kristina Panos 14 Comments

It’s the dead of winter here in the northern hemisphere, and between the pandemic and the polar vortex, we’re getting pretty tired of staring at the same four walls and eating incessantly. It’s the perfect recipe for trying something new and low-calorie, like baking a loaf of bread-shaped note paper from the stuff in the recycling bin.

[SusanLand] likes to make paper out of whatever discarded things she has on hand, including old jeans. When she tried making paper out of nothing but toilet paper tubes, it didn’t work so well, but it gave her an idea for cooking up some offbeat stationery. She beefed up the pulp with shredded office paper and corn starch, and dialed in the whole wheat hue with a pinch of yellow and orange paper. Once the pulp was ready, she poured it into bread-shaped molds made from a plastic milk jug.

This tidy introduction to making your own paper covers everything from pulping techniques to drying methods. Once the slices are dry, [SusanLand] embellishes them with a scoring tool, colored pencils, and a handful of seeds to complete the look. Check out that process in the videos after the break.

Don’t want to make paper out of your paper? Use it to weigh your car, or fold up a fleet of airplanes.

Continue reading “DIY Bread Slice Paper Goes Against The Grain” →

Minimal MQTT With Micropython

February 17, 2021 by Chris Lott 16 Comments

I have been meaning to play around with MQTT for some time now, and finally decided to take the plunge one evening last week. I had three cheap home temperature and humidity sensors, and was bothered that they often didn’t agree. Surprisingly, while the analog one had a calibration adjustment in the back, I have no idea how to calibrate the two digital ones. I took this as a sign that it was time to learn MQTT and be able to install my own, accurate sensors. Of course, I began by ordering the cheapest sensors I could find, but I can always upgrade later on.

While we have written quite a bit about MQTT in Hackaday, I had to go all the way back to 2016 to find this introductory four-part series by Elliot Williams. Five years is a long time in the tech world, but I decided to give it a try anyway. Continue reading “Minimal MQTT With Micropython” →

Software Challenge’s Solution Shows Reverse Engineering In Action

February 16, 2021 by Donald Papp 3 Comments

[0xricksanchez] participated in a software reverse-engineering challenge and recently wrote up the solution, and in so doing also documented the process used to discover it. The challenge was called Devil’s Swapper, and consisted of a small binary blob that output a short message when executed. The goal of the challenge? Discover the secret key and the secret message within. [0xricksanchez]’s writeup, originally intended just as a personal record, ended up doing an excellent job of showing how a lot of reverse engineering tools and processes get applied to software in a practical way.

What’s also great about [0xricksanchez]’s writeup is that it uses standard tools and plenty of screenshots to show what is being done, while also explaining why those actions are being chosen and what is being learned. It’s easy to follow the thought process as things progress from gathering information, to chasing leads, and finally leveraging what’s been learned. It’s a fascinating look into the process of applying the reverse engineering mindset to software, and a good demonstration of the tools. Give it a read, and see how far you can follow along before learning something new. Want more? Make sure you have checked out the Hackaday 2020 Remoticon videos on reverse engineering firmware, and doing the same for PCBs.

Using MIDI To Solve A Keyboard Shortcut Problem

February 16, 2021 by Donald Papp 4 Comments

[Pete] admits that his MIDI-based slide advance alert system is definitely a niche solution to a niche problem, but it is a wonderful example of using available tools to serve a specific need. The issue was this: [Pete] is involved in numerous presentations streamed over video, and needed a simple and effective way for the Presenter to notify the Producer (the one responsible for the video streaming and camera switching) to discreetly advance slides on cue.

To most of us, this is a simple problem to solve. Provide the presenter with a USB macro keyboard to trigger the keyboard shortcuts for slide advancement, and the job’s done. But that didn’t quite cut it for [Pete]. In their situation, the Producer is managing more than just the slides as they switch between cameras, watch the chat window, and manage the video streaming itself. Triggering slide advancement via keyboard shortcuts only works if the presentation software is in focus when the buttons are pressed, which isn’t guaranteed.

[Pete’s] solution was to make a small two-button device (one button for next slide, one for previous slide) that uses MIDI to communicate with a small custom application on the producer’s machine, and doesn’t care about application focus. Pressing the slide advance button plays a distinct tone into the producer’s headphones, plus the custom application displays “Forward”, “Back”, or “Waiting” in a window, depending on the state of the Presenter’s buttons. The design is available on Instructables for anyone wanting a closer look.

[Pete] reports that it works and it’s far more discreet than saying “next slide, please” twenty or more times per presentation. You may notice from the photo that LEGO bricks play a prominent part in the device, and if you’d like to see more of that sort of thing, make sure to check out these other brick-mountable PCB designs.