The Art And Science Of Making Beautiful Transparent Ice

For most of us, ice isn’t something we’ve thought about in detail since our high school science classes. For most of us, we pour some tap water into the ice trays, slam it in the freezer, and forget about it. Then we lob the frozen misshapen cubes into a beer and enjoy a quite literally ice-cold beverage.

However, there’s so much more fun to be had with ice if you really get into it. If you’ve ever wondered how pretentious cocktail bars make their fancy ice spheres or transparent cubes, read on!

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The Wizard Of Semiconductors

If you have three hours and you want to learn the fundamentals of semiconductors, [Tiny Tapeout] has something for you: An introduction to SiliWiz. You’ll also need the SiliWiz software (or use it online), which resembles the kind of tools that chip designers use but is meant for students to use as a learning tool

Using SiliWiz, you create layers on a virtual device, and you can use Spice to view the results. The tutorial is meant to be high-level and is suggested for students aged 14 or over (but we liked it and we are quite a bit older than that). Some more advanced material is also available at the same site.

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LTE Sniffer Ferrets Out Cellular Communications

LTE networks have taken over from older technologies like GSM in much of the world. Outfitted with the right hardware, like a software defined radio, and the right software, it’s theoretically possible to sniff some of this data for yourself. The LTESniffer project was built to do just this. 

LTESniffer is able to sniff downlink traffic from base stations using a USRP B210 SDR, outfitted with two antennas. If you want to sniff uplink traffic, though, you’ll need to upgrade to an X310 with two daughterboards fitted. This is due to the timing vagaries of LTE communication. Other solutions can work however, particularly if you just care about downlink traffic.

If you’ve got that hardware though, you’re ready to go. The software will help pull out LTE signals from the air, though it bears noting that it’s only designed to work with unencrypted traffic. It won’t help you capture the encrypted communications of network users, though it can show you various information like IMSI numbers of devices on the network. Local regulations may prevent you legally even doing this, and if so, the project readme recommends setting up your own LTE network to experiment with instead.

Cellular sniffing has always been somewhat obscure and arcane, given the difficulty and encryption involved, to say nothing of the legal implications. Regardless, some hackers will always pursue a greater knowledge of the technology around them. If you’ve been doing just that, let us know what you’re working on via the tipsline.

Toothbrush Speed Controller Secrets Revealed

Typically, when we want to build something with a DC motor, we might grab a bunch of AAs, or a single lithium cell at the very least. Electric toothbrushes often run on more humble power sources, like a single NiMH battery. They’re designed to get useful motion out of just 1.2V, and [Marian Hryntsiv] has taken a look at what makes them tick.

The article focuses on an electric toothbrush built around the Low Voltage GreenPAK™ SLG47513 chip. It’s designed to work at voltages from just 1 to 1.65 V. To make the most of the limited power available, the toothbrush stays in sleep mode most of the time when it’s not working in oral health.

[Marian] steps through the various parts of the circuit, and also explains the unique functionality baked into the brush. Of particular interest are the timer routines that guide the user through brushing each section of the mouth in turn, before a notification that tells them that 2 minutes of brushing time has elapsed. There’s also a useful explanation of the inductive charging method used.

Electric toothbrushes may be mundane home items today, but they’re an example of a product that has largely already been optimized to the nth degree. Until laser-based plaque removal or enamel regeneration technology gets off the ground, this is as good as it gets. We can dream, though!

 

Hackaday Prize 2023: A DIY Voice-Control Module

If science fiction taught us anything, it’s that voice control was going to be the human-machine interface of the future. [Dennis] has now whipped up a tutorial that lets you add a voice control module to any of your own projects.

The voice control module uses a Raspberry Pi 4 as the brains of the operation, paired with a Seeed Studio ReSpeaker 4-microphone array. The Pi provides a good amount of processing power to crunch through the audio, while the mic array captures high-quality audio from any direction, which is key to reliable performance. Rhasspy is used as the software element, which is responsible for processing audio in a variety of languages to determine what the user is asking for. Based on the voice commands received, Rhasspy can then run just about anything you could possibly require, from sending MQTT smart home commands to running external programs.

If you’ve always dreamed of whipping up your own version of Jarvis from Iron Man, or you just want a non-cloud solution to turn your lights on and off, [Dennis’s] tutorial is a great place to start. Video after the break.

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Hackaday Prize 2023: Eye-Tracking Wheelchair Interface Is A Big Help

For those with quadriplegia, electric wheelchairs with joystick controls aren’t much help. Typically, sip/puff controllers or eye-tracking solutions are used, but commercial versions can be expensive. [Dhruv Batra] has been experimenting with a DIY eye-tracking solution that can be readily integrated with conventional electric wheelchairs.

The system uses a regular webcam aimed at the user’s face. A Python script uses OpenCV and a homebrewed image segmentation algorithm to analyze the user’s eye position. The system is configured to stop the wheelchair when the user looks forward or up. Looking down commands the chair forward. Glancing left and right steers the chair in the given direction.

The Python script then sends the requisite commands via a TCP connection to an ESP32, which controls a bunch of servos to move the wheelchair’s joystick in the desired manner. This allows retrofitting the device on a wheelchair without having to modify it in an invasive manner.

It’s a neat idea, though it could likely benefit from some further development. A reverse feature would be particularly important, after all. However, it’s a great project that has likely taught [Dhruv] many important lessons about human-machine interfaces, particularly those beyond the ones we use every day. 

This project has a good lineage as well — a similar project, EyeDriveOMatic won the Hackaday prize back in 2015.

Your Childhood Inventions Brought To Life

If you are the kind of person who reads Hackaday, you probably spent time in school doodling little design day dreams. [Allen Pan] gets it, and he’s taken it upon himself to make some of those daydreams into reality. You can see how it worked out — or didn’t — in the video below.

The video starts out with suction cup boots for walking on the ceiling, a laser sword made with a mirror, a plunger gun, and lawnmower boots. Some of these were more successful than others.

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