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A weighing scale with a moving-coil meter as a display

Hackaday Prize 2022: Arduino-Powered Weighing Scale Has A Real Analog Display

July 25, 2022 by 3 Comments

Digital displays are useful for quick and accurate readout, but lots of people prefer the physical motion of a needle moving along a dial. For instance, many smartwatch users choose an analog face to show the time, and modern cars with digital dashboards often default to showing an analog speedometer. Following this trend, [Miro Pavleski] built a digital weighing scale with an analog display that not only looks neat, but also serves as a good demonstration of the way that modern scales work.

Inside, the device is built up like a typical electronic scale: the heart of the instrument is a load cell that supports the platform and bends in proportion to the weight applied. This bending motion is sensed by a set of strain gauges wired up in a Wheatstone bridge configuration. An HX711 readout chip measures the resulting voltage and converts it to a digital code that is sent to a microcontroller, in this case an Arduino Nano.

Whereas a typical scale would then simply show the resulting number on an LCD display, [Mirko] decided to use a moving coil meter driven by the Arduino’s analog output. That meter was originally designed to show currents, so [Mirko] printed a new background image using kilograms instead.

Continue reading “Hackaday Prize 2022: Arduino-Powered Weighing Scale Has A Real Analog Display” →

IOT Garage Door Opener Makes For Excellent Beginner IOT Project

July 19, 2022 by 14 Comments

If you live in a home with a garage door opener, you may have experienced one or more inevitable moments. You pull up to your home, you press the button on the garage door opener, and… nothing. Or you can’t find the garage door opener. Or you have to mash the button repeatedly to get a response. Or… you get the idea. Thanks to [Core Electronics] however, you now have the basis for using a much better device to control your own garage door: Your phone. You can see the tutorial on the web or in video format below the break.

[Michael] at [Core electronics] was tired of dealing with the inconsistencies and inconveniences of a poorly built remote for his garage door opener. When he inspected the controller board on the garage door opener itself, he found that it was already configured to allow three buttons to be connected: Up, Down, and Stop. Continue reading “IOT Garage Door Opener Makes For Excellent Beginner IOT Project” →

Style Your Tile With 3D Printed Countertops

July 15, 2022 by 18 Comments

We’re all familiar with supply chain issues as they relate to chips and DIPs, but anyone who has requested an estimate for home improvements lately knows that the problems extend to things like plywood, and probably tile, marble, and Formica. Faced with adversity when it came to renovating the kitchen, [3DPC] decided to have a go at 3D printing custom countertops instead of buying tile.

Always build a testing rig first! Polyurethane looked great when wet, but resin was the clear winner.

Since grout isn’t required here but is ultimately expected, [3DPC] beveled the edges of the tiles in order to allow for decorative ‘grout’ filler pieces that provide a nice contrast. That high-gloss shine comes from a combination of printing onto glass, the direction of the layer lines, and the resin sealer that [3DPC] hired a professional to pour. Because of these factors, the tiles have an increased transparency that makes them look super cool. Be sure to check out the brief build video after the break.

To be fair, this is not [3DPC]’s first 3D-printed home-improvement rodeo — he has already saved tens of thousands of dollars by printing instead of purchasing. For this particular project, [3DPC] calculated a total cost under $400 —  a fraction of what a professionally installed countertop would have cost. We wonder how much he’ll save on tiling the bathroom, which is already in progress. We can’t wait to see it!

Are you still without a printer? Might as well make one that can use trash. Or if you already have a printer, just make filament from recycled plastic. It’s all here among the 2022 Hackaday Prize Round 2 winners; just let your imagination wander.

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You Wouldn’t 3D Print A House, Would You?

July 13, 2022 by 66 Comments

Most houses built in the US today are platform construction: skinny two-by-fours are stacked and layered to create walls with studs. Each floor is framed on top of the other. It is fast, relatively cheap, and easy to learn how to do. However, it is not without drawbacks. Some estimates put the amount of waste generated per square foot (0.09 m2) at around 3.9 lbs (1.8 kg).

Timber framing is an older style where giant beams are used to create the structure of the house. Each timber is hand-carved and shaped, requiring skill and precision. Some cabins are still built this way because it is easy to source the timber locally and cutting into big logs is less work than cutting into lots of small logs. It’s relatively ecologically friendly, but slow and skilled-labor intensive.

We live in a world where there is a vast need for cheaper, faster, more eco-friendly housing, but finding a solution that can tick all the boxes is fiendishly difficult. Can 3D-printed housing accomplish all three of those goals? We’re not there yet, but we’re working on it.

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The OpenMV board inside a security camera shell on the left, an AprilTag on smartphone's screen on the right

Use AprilTags To Let Guests Open Your Front Gate

July 8, 2022 by 18 Comments

[Herb Peyerl] is part of a robotics team, and in his robotics endeavours, learned about AprilTags; small QR-code-like printable patterns that are easily recognizable by even primitive machine vision. Later on, when thinking about good ways to let his guests through his property’s front gate, the AprilTags turned out to be a wonderful solution. Now all he needs to do is send his guest a picture of the appropriate AprilTag, which they can present to the camera at his front gate using their smartphone.

He used an OpenMV board for this – thanks to its wide variety of available libraries, the AprilTag recognition is already baked in, and the entire script is merely a hundred lines of MicroPython. An old surveillance camera gave up its dome-shaped housing, and now the OpenMV board is doing guest access duty on a post in front of his property’s front gate. He’s shared the code with us, and says he’s personally running a slightly modified version for security reasons — not that a random burglar is likely to stumble upon this post anyway. Besides it looks like the gate would be easy for a burglar to jump over without any need for security bypass, and the convenience benefits of this hack are undeniable.

In the unlikely chance a burglar is reading this, however, don’t be sad. We do happen to have a bunch of hacks for you, too. There’s far less secure systems out there, from building RFID keyfobs to gated community access control systems, sometimes all you need is a 12 V battery. If you’re not into burglary, that’s okay too — we’ve covered other guest access hacks before, for instance, this ESP8266-powered one.

LoRa Helps With Remote Water Tank Level Sensing

July 7, 2022 by 9 Comments

[Renzo Mischianti]’s friend has to keep a water tank topped up. Problem is, the tank itself is 1.5 km away, so its water level isn’t typically known. There’s no electricity available there either — whichever monitoring solution is to be used, it has to be low-power and self-sufficient. To help with that, [Renzo] is working on a self-contained automation project, with a solar-powered sensor that communicates over LoRa, and a controller that receives the water level readings and powers the water pump when needed.

[Renzo] makes sure to prototype every part using shields and modules before committing to a design, and has already wrote and tested code for both the sensor and the controller, as well as created the PCBs. He’s also making sure to document everything as he goes – in fact, there’s whole seven blog posts on this project, covering the already completed software, PCB and 3D design stages of this project.

These worklogs have plenty of explanations and pictures, and [Renzo] shows a variety of different manufacturing techniques and tricks for beginners along the way. The last blog post on 3D designing and printing the sensor enclosure was recently released, and that likely means we’ll soon see a post about this system being installed and tested!

[Renzo] has been in the “intricately documented worklogs” business for a while. We’ve covered his 3D printed PCB mill and DIY soldermask process before, and recently he was seen adding a web interface to a 3D printer missing one. As for LoRa, there’s plenty of sensors you can build – be it mailbox sensors, burglar alarms, or handheld messengers; and now you have one more project to draw inspiration and knowledge from. [Renzo] has previously done a LoRa tutorial to get you started, and we’ve made one about LoRaWAN!

Continue reading “LoRa Helps With Remote Water Tank Level Sensing” →

Ubuntu 22.04 setup screen shown on the Google's Nest Hub display

Breaking Google Nest Hub’s Secure Boot

June 20, 2022 by 4 Comments

[frederic] tells a story about their team’s hack of a Google Nest Hub (2nd generation) — running Ubuntu on it, through bypassing Google’s boot image signature checks. As with many good hacks, it starts with FCC website pictures. Reverse-engineering a charger and USB daughterboard pin-out, they found a UART connection and broke it out with a custom adapter. With a debug console and insights into the process, they went on hacking, slicing through hardware and software until it was done with.

This story gives plenty of background and insight into both the code that was being investigated, and the way that attack targets were chosen. Through fuzzing, they found a buffer overflow in the bootloader code that could be triggered with help of a non-standard block size. USB flash drives tend to have these hard-coded, so they built a special firmware for a Pi Pico and shortly thereafter, achieved code execution. Then, they hooked into uboot functions and loaded Ubuntu, bypassing the boot image signature checks.

This is a wonderful documentation of a hacking journey, and an exciting read to boot (pun intended). The bug seems to have been patched for half a year now, so you probably can’t flash your Google Nest into Ubuntu anymore. However, you might be able to run an up-to-date Linux on your Amazon Echo.

We thank [Sven] for sharing this with us!