For Today Only, Pi=3

February 29, 2024 by Jenny List 47 Comments

In 1897 the state assembly of the American state of Indiana famously tried and failed to pass a bill which would have had the effect of denying the value of the mathematical constant Pi. It was an attempt to define a method to “square the circle”, or draw a square of the same area as a given circle through a series of compass and straight edge steps. It’s become something of a running joke and internet meme, and of course defining Pi exactly remains as elusive as ever.

Today and today alone though, you can in one sense claim that Pi is 3, because it’s twelve years since the launch of the original Raspberry Pi. The 29th of February 2012 was a leap day, and today being the third leap day since, could be claimed by a date pedant to be the third birthday of the little board from Cambridge. It’s all a bit of fun, but the Pi folks have marked the occasion by featuring an LED birthday cake.

Three leap days ago, your scribe was up at the crack of dawn to be one of the first to snag a board, only to witness the websites of the two distributors at the time, RS and Farnell, immediately go down under the denial of service formed by many thousands of other would-be Pi owners with the same idea. It would be lunchtime before the sites recovered enough to slowly buy a Pi, and it would be May before the computer arrived.

The Pi definitely arrived with a bang, but at tweleve years old is it still smoking? We think so, while it’s normalized the idea of an affordable little board to run Linux to the extent that it’s one of a crowd, the Pi folks have managed to stay relevant and remain the trend setter for their sector rather than Arduino-style becoming an unwilling collective term.

We’ve said this before here at Hackaday, that while the Pi boards are good, it’s not them alone which sets them apart from the clones but their support and software. Perhaps their greatest achievement is that a version of the latest Raspberry Pi OS can still run on that board ordered in February 2012, something unheard of elsewhere in single board computers. If you still have an original Pi don’t forget this, while it’s not the quickest any more there are still plenty of tasks at which they can excel. Meanwhile with their move into branded silicon and their PCIe architecture move we think things are looking exciting, and we look forward to another 12 years and three birthdays for them. Happy 3rd birthday, Raspberry Pi!

Reggaeton-Be-Gone Disconnects Obnoxious Bluetooth Speakers

February 23, 2024 by Bryan Cockfield 29 Comments

If you’re currently living outside of a Spanish-speaking country, it’s possible you’ve only heard of the music genre Reggaeton in passing, if at all. In places with large Spanish populations, though, it would be more surprising if you hadn’t heard it. It’s so popular especially in the Carribean and Latin America that it’s gotten on the nerves of some, most notably [Roni] whose neighbor might not do anything else but listen to this style of music, which can be heard through the walls. To solve the problem [Roni] is now introducing the Reggaeton-Be-Gone. (Google Translate from Spanish)

Inspired by the TV-B-Gone devices which purported to be able to turn off annoying TVs in bars, restaurants, and other places, this device can listen to music being played in the surrounding area and identify whether or not it is hearing Reggaeton. It does this using machine learning, taking samples of the audio it hears and making decisions based on a trained model. When the software, running on a Raspberry Pi, makes a positive identification of one of these songs, it looks for Bluetooth devices in the area and attempts to communicate with them in a number of ways, hopefully rapidly enough to disrupt their intended connections.

In testing with [Roni]’s neighbor, the device seems to show promise although it doesn’t completely disconnect the speaker from its host, instead only interfering with it enough for the neighbor to change locations. Clearly it merits further testing, and possibly other models trained for people who use Bluetooth speakers when skiing, hiking, or working out. Eventually the code will be posted to this GitHub page, but until then it’s not the only way to interfere with your neighbor’s annoying stereo.

Thanks to [BaldPower] and [Alfredo] for the tips!

Pi Pico Enhances RadioShack Computer Kit

February 20, 2024 by Bryan Cockfield 9 Comments

While most of us now remember Radio Shack as a store that tried to force us to buy batteries and cell phones whenever we went to buy a few transistors and other circuit components, for a time it was an innovative and valuable store for electronics enthusiasts before it began its long demise. Among other electronics and radio parts and kits there were even a few DIY microcomputers, and even though it’s a bit of an antique now a Raspberry Pi Pico is just the thing to modernize this Radio Shack vintage microcomputer kit from the mid 80s.

The microcomputer kit itself is built around the 4-bit Texas Instruments TMS1100, one of the first mass-produced microcontrollers. The kit makes the processor’s functionality more readily available to the user, with a keypad and various switches for programming and a number of status LEDs to monitor its state. The Pi Pico comes into the equation programmed to act as a digital clock with an LED display to drive the antique computer. The Pi then sends a switching pulse through a relay to the microcomputer, which is programmed as a binary counter.

While the microcomputer isn’t going to win any speed or processing power anytime soon, especially with its clock signal coming from a slow relay module, the computer itself is still fulfilling its purpose as an educational tool despite being nearly four decades old. With the slow clock speeds it’s much more intuitive how the computer is stepping through its tasks, and the modern Pi Pico helps it with its tasks quite well. Relays on their own can be a substitute for the entire microcontroller as well, like this computer which has a satisfying mechanical noise when it’s running a program.

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A Straightforward AI Voice Assistant, On A Pi

February 20, 2024 by Jenny List 6 Comments

With AI being all the rage at the moment it’s been somewhat annoying that using a large language model (LLM) without significant amounts of computing power meant surrendering to an online service run by a large company. But as happens with every technological innovation the state of the art has moved on, now to such an extent that a computer as small as a Raspberry Pi can join the fun. [Nick Bild] has one running on a Pi 4, and he’s gone further than just a chatbot by making into a voice assistant.

The brains of the operation is a Tinyllama LLM, packaged as a llamafile, which is to say an executable that provides about as easy a one-step access to a local LLM as it’s currently possible to get. The whisper voice recognition sytem provides a text transcript of the input prompt, while the eSpeak speech synthesizer creates a voice output for the result. There’s a brief demo video we’ve placed below the break, which shows it working, albeit slowly.

Perhaps the most important part of this project is that it’s easy to install and he’s provided full instructions in a GitHub repository. We know that the quality and speed of these models on commodity single board computers will only increase with time, so we’d rate this as an important step towards really good and cheap local LLMs. It may however be a while before it can help you make breakfast.

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The 200% Typewriter

February 19, 2024 by Kristina Panos 3 Comments

You know, the really sad truth about cyberdecks and cyberdeck-adjacent builds is that many of them just end up on the shelf, collecting dust while waiting for the dystopian future. Well, not this one. No, [jefmer] says their Portable Pi sees daily use, and even comes along on the go.

Since [jefmer] is “temperamentally unsuited to 3D printing”, the Pi 4B and its accessories are nestled in a rugged, splash-proof case under some acrylic sheets. One of those accessories, the keyboard, is a KPrepublic BM40 with Gateron Yellows. In order to get used to the number and symbols layer, [jefmer] laid down some great-looking labels above the keyboard.

Although the build started with an SD card for storage, [jefmer] has since upgraded to a 120 GB SSD. This required a beefy battery pack, but the difference is that it gets around four hours of power versus five hours when using an SD card.

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All-Sky Camera Checks For Aurora

February 16, 2024 by Bryan Cockfield 4 Comments

The aurora borealis (and its southern equivalent, the aurora australis) is a fleeting and somewhat rare phenomenon that produces vivid curtains of color in the sky at extreme latitudes. It’s a common tourist activity to travel to areas where the aurora is more prevalent in order to catch a glimpse of it. The best opportunities are in the winter though, and since most people don’t want to spend hours outside on a cold night night in high latitudes, an all-sky camera like this one from [Frank] can help notify its users when an aurora is happening.

Because of the extreme temperatures involved, this is a little more involved than simply pointing a camera at the sky and hoping for the best. The enclosure and all electronics need to be able to withstand -50°C and operate at at least -30. For the enclosure, [Frank] is going with PVC tubing with a clear dome glued into a top fits to the end of the pipe, providing a water-resistant enclosure. A Raspberry Pi with a wide-angle lens camera sits on a 3D printed carriage so it can easily slide inside. The electronics use power-over-ethernet (PoE) rather than a battery due to the temperature extremes, which conveniently provides networking capabilities for viewing the images.

This is only part one of this build — in part two [Frank] is planning to build a system which can use this camera assembly to detect the aurora automatically and send out notifications when it sees it. Watching the night sky from the comfort of a warm house or sauna isn’t the only reason for putting an all-sky camera to use, either. They can also be used to observe meteors as they fall and then triangulate the position of the meteorites on the ground.

Pi 5 And SDR Team Up For A Digital Scanner You Can Actually Afford

February 10, 2024 by Dan Maloney 27 Comments

Listening to police and fire calls used to be a pretty simple proposition: buy a scanner, punch in some frequencies — or if you’re old enough, buy the right crystals — and you’re off to the races. It was a pretty cheap and easy hobby, all things considered. But progress marches on, and with it came things like trunking radio and digital modulation, requiring ever more sophisticated scanners, often commanding eye-watering prices.

Having had enough of that, [Top DNG] decided to roll his own digital trunking scanner on the cheap. The first video below is a brief intro to the receiver based on the combination of an RTL-SDR dongle and a Raspberry Pi 5. The Pi is set up in headless mode and runs sdrtrunk, which monitors the control channels and frequency channels of trunking radio systems, as well as decoding the P25 digital modulation — as long as it’s not encrypted; don’t even get us started on that pet peeve. The receiver also sports a small HDMI touchscreen display, and everything can be powered over USB, so it should be pretty portable. The best part? Everything can be had for about $250, considerably cheaper than the $600 or so needed to get into a purpose-built digital trunking scanner — we’re looking at our Bearcat BCD996P2 right now and shedding a few tears.

The second video below has complete details and a walkthrough of a build, from start to finish. [Top DNG] notes that sdrtrunk runs the Pi pretty hard, so a heat sink and fan are a must. We’d probably go with an enclosure too, just to keep the SBC safe. A better antenna is a good idea, too, although it seems like [Top DNG] is in the thick of things in Los Angeles, where LAPD radio towers abound. The setup could probably support multiple SDR dongles, opening up a host of possibilities. It might even be nice to team this up with a Boondock Echo. We’ve had deep dives into trunking before if you want more details.

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