Pi-Powered Anti-Cat Trap Soaks Felines And Other Animals

July 10, 2014 by 52 Comments

[Joshua] has a problem with cats. They like pooping in his garden. He decided to take action with this awesome automated and humane cat trap.

Now just to clarify, he did attempt a few other alternatives before going all out in cat defense – the easiest solution would be to get a cat of his own, but alas, he’s not a cat person.

The system uses a Raspberry Pi in a waterproofed housing with a PiCam. He’s written some rudimentary code to make use of the PiCam Python Library which also allows him to record pre-cat-trapping footage, much for our enjoyment. When motion is sensed, the Pi trips a 24VAC solenoid water valve, which turns on the sprinkler and quickly soaks the intruder.

Stick around after the break for quite a few videos catching the furry little buggers in the act!

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Recliner Sofa Given The Power Of The Pi

January 4, 2014 by 20 Comments

pi-sofa

If you go to buy a sofa these days you’ll not only be greeted with the option of one or more reclining positions, but a fully modern unit comes with motorized reclining. That simply wasn’t convenient enough for [Nicki] and [Kevin] who wanted to control the feature from a smartphone rather than a physical interface (buttons) on the side of the furniture. What resulted is the PiSofa, a Raspberry Pi connected to the furniture’s electronics with the help of a relay board.

This is most certainly a hack, but no doubt one with a lot of finesse. Check out that white PCB. That’s right, it’s a factory spun board to keep things nice and neat. They went with one of our favorite tricks by housing everything inside of a food storage container. After some Ruby coding the Pi now has complete control of the sofa. We’re not overstating this. It literally is the only way to control it because the original buttons no longer work. But that’s okay, turns out not only does it work with their smartphones, but with a [Kevin’s] Pebble watch as well.

We can’t think of any past hacks that specifically targeted the couch. But here’s a hammock that you can drive down the street.

Black Hat 2009: Powerline And Optical Keysniffing

July 29, 2009 by 21 Comments

sniff

The 2009 edition of the Black Hat security conference in Las Vegas has just begun. The first interesting talk we saw was [Andrea Barisani] and [Daniele Bianco]’s Sniff Keystrokes With Lasers/Voltmeters. They presented two methods for Tempest style eavesdropping of keyboards.

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3D Print A Drill-Powered Helicopter Toy Because It’s Simply Fun

May 14, 2024 by 8 Comments

These days, you can get a fully remote-control helicopter that you can fly around your house for about $30. Maybe less. Back in the day, kids had to make do with far simpler toys, like spinning discs that just flew up in the air. [JBV Creative] has built a toy just like that with his 3D printer. It may be simple, but it also looks pretty darn fun.

The design is straightforward. It uses a power drill to spin up a geartrain, which in turn drives a small disc propeller. Spin the propeller fast enough and it’ll launch high into the air. The geartrain mounts to the drill via the chuck, and it interfaces with the propeller with a simple toothed coupler. Alternatively, there’s also a hand-cranked version if you don’t have a power drill to hand.

Launching is easy. First, the drill spins the propeller up to speed. Then, when the drill’s trigger is released, it slows down, and the propeller spins free of the toothed coupler, with the lift it generates carrying it into the sky.

Files are available online for those interested. We could imagine this toy could make the basis for a great design competition. Students could compete to optimise the design with more effective gear ratios or better airfoils. We’ve seen similar designs before, too. Video after the break.

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Solar Panel Keeps Cheap Digital Calipers Powered Up

April 20, 2024 by 40 Comments

There’s no doubt that cheap digital calipers are useful, especially when designing 3D-printed parts. Unfortunately, cheap digital calipers are also cheap, and tend to burn through batteries quickly. Sure, you can remove the battery when you’re done using them, but that’s for suckers — winners turn to solar power to keep their calipers always at the ready.

[Johan]’s solar upgrade begins with, unsurprisingly, a solar cell, one that just fits on the back of his digital calipers. Like most of these cheap calipers, this one is powered by a single 1.5 V LR44 button cell, while the polycrystalline solar cell is rated for 5 V, so [Johan] used a red LED as a crude voltage regulator. He also added a stack of fourteen 100 μF SMD capacitors soldered together in parallel. The 1206 devices form a 1,400 μF block that’s smaller than the original button cell so that everything fits in the vacated battery compartment. It’s pretty slick.

Given their agreeable price point, digital calipers are a tempting target for hacking. We’ve seen a ton of them, from accessibility add-ons to WiFi connectivity and even repurposing them for use as DROs. Ever wonder how these things work? We’ve looked at that, too.

A standard-compliant MXM card installed into a laptop, without heatsink

MXM: Powerful, Misused, Hackable

April 18, 2024 by 23 Comments

Today, we’ll look into yet another standard in the embedded space: MXM. It stands for “Mobile PCI Express Module”, and is basically intended as a GPU interface for laptops with PCIe, but there’s way more to it – it can work for any high-power high-throughput PCIe device, with a fair few DisplayPort links if you need them!

You will see MXM sockets in older generations of laptops, barebones desktop PCs, servers, and even automotive computers – certain generations of Tesla cars used to ship with MXM-socketed Nvidia GPUs! Given that GPUs are in vogue today, it pays to know how you can get one in low-profile form-factor and avoid putting a giant desktop GPU inside your device.

I only had a passing knowledge of the MXM standard until a bit ago, but my friend, [WifiCable], has been playing with it for a fair bit now. On a long Discord call, she guided me through all the cool things we should know about the MXM standard, its history, compatibility woes, and hackability potential. I’ve summed all of it up into this article – let’s take a look!

This article has been written based on info that [WifiCable] has given me, and, it’s also certainly not the last one where I interview a hacker and condense their knowledge into a writeup. If you are interested, let’s chat!

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Linear Feedback Shift Registers For FPGAs

April 6, 2024 by 28 Comments

If you want to start an argument at a Hackaday meeting, you have only to ask something like “How much does this weigh?” or “What time is it?” But if you really want to start a street brawl, you can always say, “Are these numbers random?” Making random numbers that are actually random is actually a tough nut to crack. Most of what we do is, technically, pseudo-random (but we’ll say random number and assume you know what we mean). One way to generate seemingly random sequences is to use a linear feedback shift register or LFSR. You can use LFSRs in software, but they are also very useful in hardware design and [Adam Taylor] takes us through his use of them on FPGAs in a recent post. Continue reading “Linear Feedback Shift Registers For FPGAs” →