Coffee Maker Gives Plants An Automatic Drip

Somehow, [Jeremy S   Cook]’s wife was able to keep a Keurig machine going for 10 years before it quit slinging caffeine. [Jeremy] got it going again, but decided to buy a new one when he saw how it was inside from a decade of water deposits.

But why throw the machine out like spent coffee grinds? Since the pump is still good, he decided to turn it into an automatic plant watering machine. Now the Keurig pumps water using a Raspberry Pi Zero W and a transistor. [Jeremy] can set up watering cron jobs with PuTTY, or push water on demand during dry spells. We love that he wired up a soil moisture sensor to the red/blue LEDs around the brew button — red means the plant is thirsty, purple means water is flowing, and no light means the plant is quenched and happy.

This project is wide open, but cracking into the Keurig is up to you. Fortunately, that part of the build made it into the video, which is firmly planted after the break.

Old coffee makers really do seem suited to taking up plant care in retirement. Here’s a smart garden made from an espresso machine.

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Freeze Laser Beams — Sort Of

They say a picture is worth a thousand words, and by that logic a video must be worth millions. However, from nearly the dawn of photography around 1840, photographers have made fake photographs.  In modern times, Photoshop and Deepfake make you mistrust images and videos. [Action Lab] has a great camera trick in which it looks like he can control the speed of light. You can see the video below.

You probably can guess that he can’t really do it. But he has videos where a real laser beam appears to slowly move across the screen like a laser blaster shot in a movie. You might think you only need to slow down the video speed, but light is really fast, so you probably can’t practically pull that stunt.

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The Rusty Nail Award For Worst WiFi Antenna

In general, you get what you pay for, and if what you pay for is a dollar-store WiFi antenna that claims to provide 12 dBi of signal gain, you shouldn’t be surprised when a rusty nail performs better than it.

The panel antenna that caught [Andrew McNeil]’s eye in a shop in Rome is a marvel of marketing genius. He says what caught his eye was the Windows Vista compatibility label, a ploy that really dates this gem. So too does the utterly irrelevant indication that it’s USB compatible when it’s designed to plug into an SMA jack on a WiFi adapter. [Andrew]’s teardown was uninspiring, revealing just a PCB with some apparently random traces to serve as the elements of a dipole. We found it amusing that the PCB silkscreen labels the thru-holes as H1 to H6, which is a great way to make an uncrowded board seem a bit more important.

The test results were no more impressive than the teardown. A network analyzer scan revealed that the antenna isn’t tuned for the 2.4-GHz WiFi band at all, and practical tests with the antenna connected to an adapter were unable to sniff out any local hotspots. And just to hammer home the point of how bad this antenna is, [Andrew] cobbled together a simple antenna from an SMA connector and a rusty nail, which handily outperformed the panel antenna.

We’ve seen plenty of [Andrew McNeil]’s WiFi antenna videos before, like his umbrella and tin can dish. We like the sanity he brings to the often wild claims of WiFi enthusiasts and detractors alike, especially when he showed that WiFi doesn’t kill houseplants. We can’t help but wonder what he thinks about the current 5G silliness.

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Researchers Break FPGA Encryption Using FPGA Encryption

FPGAs are awesome — they can be essentially configured into becoming any computing device you want. Simply load your selected bitstream into the device on boot, and it behaves like a different piece of hardware. With great power comes great responsibility.

You might try to hack a given FPGA system by getting between the EEPROM that stores the bitstream and the FPGA during bootup, but FPGA manufacturers are a step ahead of you. Xilinx 7 series FPGAs have an onboard encryption and signing engine, and facilities for storing a secret key. Once the security bit is set, bitstreams coming in have to be encrypted to protect from eavesdropping, and HMAC-signed to assure that they are authentic. You can’t simply read the bitstream in transit or inject your own.

Researchers at Ruhr University Bochum and Max Planck Institute for Cybersecurity and Privacy in Germany have figured out a way to use the FPGA’s own encryption engine against itself to break both of these security guarantees for the entire mainstream 7-series. The attack abuses a MultiBoot function that allows you to specify an address to begin execution after reboot. The researchers send 32 bits of the encoded payload as a MultiBoot address, the FPGA decrypts it and stores it in a register, and then resets because their command wasn’t correctly HMAC signed. But because the WBSTAR register is meant to be readable on boot after reset, the payload is still there in its decrypted form. Repeat for every 32 bits in the bitstream, and you’re done.

Pulling off this attack requires physical access to the FPGA’s debug pins and up to 12 hours, so you only have to worry about particularly dedicated adversaries, but the results are catastrophic — if you can reconfigure an FPGA, you can make it do essentially anything. Security-sensitive folks, we have three words of consolation for you: “restrict physical access”.

What does this mean for Hackaday? If you’re looking at a piece of hardware with a hardened Xilinx 7-series FPGA in it, you’ll be able to use it, although it’s horribly awkward for debugging due to the multi-hour encryption procedure. Anyone know of a good side-channel bootloader for these chips? On the other hand, if you’re just looking to dig secrets out from the bitstream, this is a one-time cost.

This hack is probably only tangentially relevant to the Symbiflow team’s effort to reverse-engineer an open-source toolchain for this series of FPGAs. They are using unencrypted bitstreams for all of their research, naturally, and are almost done anyway. Still, it widens the range of applicability just a little bit, and we’re all for that.

[Banner image is a Numato Lab Neso, and comes totally unlocked naturally.]

How To Keep Unique Equipment Running When Parts Run Out

[JGlass] deals with public-facing technology, which he says includes things like theatre equipment, retail displays, and museum displays. Many of these pieces of technology are literally one-of-a-kind devices, even if they were constructed from what was once off-the-shelf, commercially available parts. When these machines need servicing, replacement parts aren’t always available, and reverse engineering comes in handy. He recently began documenting exactly how to approach this process by using the identification and replacement of an obsolete 7-segment industrial display as an example.

The particular part shown is the Lascar EM32-4-LED, which up and died in a unique piece of equipment. The trouble is that the EM32-4-LED is out of production and unobtainable, and the Programmable Logic Controller (PLC) that drives the whole thing is a black box that cannot be modified. It’s very good news that a datasheet exists, but that’s often just a starting point. To create a one-off, drop-in solution requires a combination of research, troubleshooting, and design work.

To do this, [JGlass] starts off by walking through datasheet elements and explains that it’s important to build a high level understanding of function first, then drill down into details, and always be ready to verify, challenge, or throw out one’s assumptions. After establishing a high level understanding comes matching physical evidence to things like block and functional diagrams, then cracking open the faulty component to see if anything else can be learned. Only then are multimeters and probes taken out for more active research. All of this sleuthing must always be done with the end goal firmly in mind: creating a new device that acts like the one being replaced. Without focus, one can easily get lost in details and unknowns.

Reverse Engineering is a process, and the more tools, the better. If you missed our earlier post about a hacker’s guide to JTAG, here’s your chance to check it out and be all the more prepared for the next time you need to do some electron detective work of your own.

So. You Bought A VNA. Now What?

It’s never too late in life for new experiences, but there’s a new experience I had a few weeks ago that I wasn’t expecting. I probably received my first piece of test equipment – a multimeter –  in the early 1980s, and since then every time I’ve received a new one, whether an oscilloscope, logic analyser, spectrum analyser or signal generator, I’ve been able to figure out how to use it. I have a good idea what it does, and I can figure out whatever its interface may be to make it do what I want it to. My new experience came when I bought a piece of test equipment, and for the first time in my life didn’t have a clue how to use it.

That instrument is a Vector Network Analyser, or VNA, and it’s worth spending a while going through the basics in case anyone else is in the same position. My VNA is not a superlative piece of high-end instrumentation that cost the GDP of a small country, it’s the popular $50 NanoVNA that has a fairly modest frequency range and performance, but is still a functional VNA that can take useful measurements. But I’m a VNA newbie, what does a VNA do? Continue reading “So. You Bought A VNA. Now What?”

Pouring Creativity Into Musical Upcycling Of Plastic Bottles

Convenient and inexpensive, plastic beverage bottles are ubiquitous in modern society. Many of us have a collection of empties at home. We are encouraged to reduce, reuse, and recycle such plastic products and [Kaboom Percussion] playing Disney melodies on their Bottlephone 2.0 (video embedded below) showcases an outstanding melodic creation for the “reuse” column.

Details of this project are outlined in a separate “How we made it” video (also embedded below). Caps of empty bottles are fitted with commodity TR414 air valves. The pitch of each bottle is tuned by adjusting pressure. Different beverage brands were evaluated for pleasing tone of their bottles, with the winners listed. Pressure levels going up to 70 psi means changes in temperature and inevitable air leakage makes keeping this instrument in tune a never-ending task. But that is a relatively simple mechanical procedure. What’s even more impressive on display is the musical performance talent of this team, assisted by some creative video editing. Sadly for us, such skill does not come in a bottle. Alcohol only makes us believe we are skilled without improving actual skill.

But that’s OK, this is Hackaday where we thrive on building machines to perform for us. We hope it won’t be long before a MIDI-controlled variant is built by someone, perhaps incorporating an air compressor for self-tuning capabilities. We’ve featured bottles as musical instruments before, but usually as wind instruments like this bottle organ or the fipple. This is a percussion instrument more along the lines of the wine glass organ. It’s great to see different combinations explored, and we are certain there are more yet to come.

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