Machine Learning Gives Cats One More Way To Control Their Humans

August 26, 2022 by Dan Maloney 9 Comments

For those who choose to let their cats live a more or less free-range life, there are usually two choices. One, you can adopt the role of servant and run for the door whenever the cat wants to get back inside from their latest bird-murdering jaunt. Or two, install a cat door and let them come and go as they please, sometimes with a “present” for you in their mouth. Heads you win, tails you lose.

There’s another way, though: just let the cat ask to be let back in. That’s the approach that [Tennis Smith] took with this machine-learning kitty doorbell. It’s based on a Raspberry Pi 4, which lives inside the house, and a USB microphone that’s outside the front door. The Pi uses Tensorflow Lite to classify the sounds it picks up outside, and when one of those sounds fits the model of a cat’s meow, a message is dispatched to AWS Lambda. From there a text message is sent to alert [Tennis] that the cat is ready to come back in.

There’s a ton of useful information included in the repo for this project, including step-by-step instructions for getting Amazon Web Services working on the Pi. If you’re a dog person, fear not: changing from meows to barks is as simple as tweaking a single line of code. And if you’d rather not be at the beck and call of a cat but still want to avoid the evidence of a prey event on your carpet, machine learning can help with that too.

[via Tom’s Hardware]

Multispectral Imaging System Built With Raspberry Pi

August 25, 2022 by Lewin Day 10 Comments

Multispectral imaging can be a useful tool, revealing all manner of secrets hidden to the human eye. [elad orbach] built a rig to perform such imaging using the humble Raspberry Pi.

The project is built inside a dark box which keeps outside light from polluting the results. A camera is mounted at the top to image specimens installed below, which the Pi uses to take photos under various lighting conditions. The build relies on a wide variety of colored LEDs for clean, accurate light output for accurate imaging purposes. The LEDs are all installed on a large aluminium heatsink, and can be turned on and off via the Raspberry Pi to capture images with various different illumination settings. A sheath is placed around the camera to ensure only light reflected from the specimen reaches the camera, cutting out bleed from the LEDs themselves.

Multispectral imaging is particularly useful when imaging botanical material. Taking photos under different lights can reveal diseases, nutrient deficiencies, and other abnormalities affecting plants. We’ve even seen it used to investigate paintings, too. Video after the break.

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Macintosh Classic II With E-Ink Display

August 24, 2022 by Bryan Cockfield 30 Comments

As various antique computers age, it becomes increasingly hard to operate them as hardware begins to physically fail. Keeping these systems up and running often requires scavenging parts from other machines which are only becoming harder to find as time goes on. But if you throw out the requirement of using only era-appropriate components, there are some interesting ways to revive older devices with a few touches of modern tech, like this Mac Classic with a unique display.

The Macintosh Classic II was the successor to the first Macintosh computer Apple sold that had a price tag under $1000. As such, there were some lower specs for this machine such as the monochrome 512×342 display. This one has been retrofitted with an e-ink display which actually gives it some of the same grayscale aesthetic as the original. The e-ink display is driven by a Raspberry Pi which displays a replica System 7 environment and a set of photos.

While the only part of the computer that’s original is the shell at this point, the project’s creator [Dave] also built in support for the Apple Desktop Bus through an Arduino so the original Apple mouse and keyboard can be used. While it’s largely an illusion of a working Mac Classic, we still appreciate the aesthetic.

If you’re more of a classic Apple purist, though, take a look at this SE/30 which uses almost entirely original parts with the exception of a Raspberry Pi to allow it to communicate with the modern Internet.

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Is This The Oldest Open Source HVAC Project In Existence?

August 22, 2022 by Dave Rowntree 19 Comments

Homebrew HVAC systems are one of those projects that take such a big investment of time, effort and money that you’ve got to be a really dedicated (ideally home-owning) hacker with a wide variety of multidisciplinary skills to pull off an implementation that can work in reality. One such HVAC hacker is [Vadim Tkachenko] with his multi-zone Home Climate Control (HCC) project that we covered first back in 2007. We now have rare opportunity to look at the improvements fifteen years of part-time development can produce, when a project is used all day, all year round in their own home. At the start, things were simple, just opening and closing ventilators with none of those modern MQTT-driven cloud computing stuff. Continue reading “Is This The Oldest Open Source HVAC Project In Existence?” →

Livestreaming Backpack Takes Streaming On-The-Go

August 19, 2022 by Bryan Cockfield 17 Comments

Anyone who’s anyone on the internet these days occasionally streams content online. Whether that’s the occasional livestream on YouTube or an every day video game session on Twitch, it’s definitely a trend that’s here to stay. If you want to take your streaming session on the go, though, you’ll need some specialized hardware like [Melissa] built into this livestreaming backpack.

[Melissa] isn’t actually much of a streamer but built this project just to see if it could be done. The backpack hosts a GoPro camera with a USB interface, mounted on one of the straps of the pack with some 3D printed parts, allowing it to act as a webcam. It is plugged into a Raspberry Pi which is set up inside the backpack, and includes a large heat sink to prevent it from overheating in its low-ventilation environment. There’s also a 4G modem included along with a USB battery pack to keep everything powered up.

The build doesn’t stop at compiling hardware inside a backpack, though. [Melissa] goes into detail on the project’s page about how to get all of the hardware to talk amongst themselves and where the livestream is setup as well. If you’d like a more permanently-located streaming setup with less expensive hardware, we have seen plenty of builds like this which will get the job done as well.

Loki Is Part Cyberdeck, Part Sinclair Spectrum, And Pretty Tricky

August 11, 2022 by Dan Maloney 5 Comments

You’ve got to watch out for Loki — he’s a trickster, after all, and he might make you think this semi-cyberdeck mash-up machine is named after him, when the backstory on this build is more interesting than anything in the current Marvel scene.

According to [Steve Anderson], Loki was the name of a mocked-up machine that Sinclair teased in the mid-1980s as a competitor for the Amiga. [Steve] coveted the vaporware machine and never quite got over it, but rather than pine for something that never existed, he created his own Loki. He only loosely qualifies the machine as a cyberdeck — it has some features of the genre, like a Raspberry Pi and a cast-off iPad screen for a display, but isn’t really intended to be as portable as a real cyberdeck. To scratch his Sinclair itch, the machine also includes a ZX Uno, which is an FPGA emulator of the Sinclair Spectrum. The keyboard is hand-wired using mechanical switches, and is backed up by a Pico running custom software so it can talk both USB and PS/2.

[Steve] has much more detail on Loki and his other cyberdeck builds over on his blog, which you should probably check out. Somewhat surprisingly, it doesn’t look like he’s entered Loki in our new Cyberdeck Contest that just launched. Hopefully that’s just an oversight.

Converting An 80s Typewriter Into A Linux Terminal

August 4, 2022 by Dan Maloney 26 Comments

Typewriters may be long past their heyday, but just because PCs, word processor software, and cheap printers have made them largely obsolete doesn’t mean the world is better off without them. Using a typewriter is a rich sensory experience, from the feel of the keys under your fingers that even the clickiest of PC keyboards can’t compare with, to the weirdly universal sound of the type hitting paper.

So if life hands you a typewriter, why not put it back to work? That’s exactly what [Artillect] did by converting an 80s typewriter into a Linux terminal. The typewriter is a Brother AX-25, one of those electronic typewriters that predated word processing software and had a daisy wheel printhead, a small LCD display, and a whopping 8k of memory for editing documents. [Artillect] started his build by figuring out which keys mapped to which characters in the typewriter’s 8×11 matrix, and then turning an Arduino and two multiplexers loose on the driving the print head. The typewriter’s keyboard is yet used for input, as the project is still very much in the prototyping phase, so a Raspberry Pi acts as a serial monitor between the typewriter and a laptop. The video below has a good overview of the wiring and the software, and shows the typewriter banging out Linux command line output.

For now, [Artillect]’s typewriter acts basically like an old-school teletype. There’s plenty of room to take this further; we’d love to see this turned into a cyberdeck complete with a built-in printer, for instance. But even just as a proof of concept, this is pretty great, and you can be sure we’ll be trolling the thrift stores and yard sales looking for old typewriters.

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