The best part is that the status can been seen on both sides of the door so you don’t forget to keep it updated. Or maybe it’s the super-low part count. There’s no BLE, LoRa, or Wi-Fi, just two sets of red and green LEDs, a three-way switch, and a power source. Well, and current-limiting resistors of course.
[Bob] already had all the components on hand, including the nifty enclosure, which is another great thing about this build. Like [Bob] says, you could house the control side of this circuit in just about anything you’ve got lying around.
Don’t you hate getting up in the middle of the night to use the bathroom? The worst part is not being able to see what you’re doing, but if you turn on a light, you’ll lose your night vision. Nightlights are supposed to be the best solution, but are usually too bright for 3 AM excursions and can end up leaking light into the bedroom. What the bathroom needs is a purpose-built nightlight that uses red light so you don’t lose your night vision.
This simple, wall-mounted night light is just the thing. All it takes is two AA batteries, a resistor, a red LED, and an SPST push button. [Vchaney] even made their own battery contacts. The genius part of this build is in the adjustable LED, which is fitted into a ball that moves around in a socket so you can aim it wherever you need to see. All the files are available if you want to print one for yourself.
[3DprintedLife] sure does hate bread crust. Not the upper portion of homemade bread, mind you — just that nasty stuff around the edges of store-bought loaves. Several dozen hours of CAD later, [3DprintedLife] had themselves a crust-cutting robot that also chops vegetables.
This De-Cruster 9000 is essentially a 2-axis robotic guillotine over a turntable. It uses a Raspberry Pi 4 and OpenCV to seek and destroy bread crusts with a dull dollar store knife. Aside from the compact design, our favorite part has to be the firmware limit switches baked into the custom control board. The stepper drivers have this fancy feature called StallGuard™ that constantly reads the back EMF to determine the load the motor is under. If you have it flag you right before the motor hits the end of the rail and stalls, bam, you have a firmware limit switch. Watch it remove crusts and chop a lot of carrots with faces after the break.
Dishwashers are great at washing dishes and even rinsing them, most of the time. Where they tend to fail is in the drying part. Somehow these things dry hot enough to warp stoneware dishes, but not so well that things are actually dry when you open the door. Blame it on the lack of air movement.
[Ivan Stepaniuk] is listening for the dishwasher’s frequencies with a microphone, amplifying them with a trusty LM386, and using an STM32 blue pill to crunch the audio. [Ivan] has plans to incorporate an ESP8266 board for IoT, presumably to get a notification when the door has been opened successfully. Check out the demo after the break.
Over the past years, the trend has become to ditch anything with wires. This has led to many people dropping wired earphones and headphones for wireless (Bluetooth) versions. Yet along with the freedom from having the wires snagged on something and having earphones painfully torn out of your ears comes the very real risk of having them drop out of your ears to land potentially very inconvenient.
In Japan this has led to a big issue for railway companies, where throngs of commuters will often accidentally drop possessions onto the tracks. Staff members will then use a mechanical claw (‘magic hand’) to fetch them without having to risk their life by jumping down. With small items such as wireless earphones, this is however not so easy. With 947 cases of dropped earphones in the period of July-September in just the Tokyo area, this has led to desperate staff members coming up with new methods of easily retrieving the small gadgets.
Solutions range from putting something sticky like tape at the end of a stick, to modifying vacuum cleaners. Most recently Tokyo railway company JR East has collaborated with Panasonic to develop a vacuum cleaner-like device that is especially designed to easily retrieve such small items from the tracks, according to the Japan Times article.
The embedded video (also found after the break) from a Japanese broadcaster describes the issue in detail, along with tips on how to properly wear earphones so that they’re far less likely to fall out when you’re waiting on the tram or walking down the street. While it’s possible to fetch your dropped wireless earphones from the tracks, having someone step on it right after it falls out of your ear on the street is less easy to recover from.
In a kind of reverse twist on the doorbell, [TheStaticTurtle] whipped up a system to mute his computer’s microphone whenever someone opens the door to his room. He lives in France, where the government announced a strict lockdown last Friday. Like many university students around the world these days, he is now forced to take online classes. Even though he has his own room, occasionally someone will barge in and announce something, often to [TheStaticTurtle]’s embarrassment. Â When his classmates suddenly heard “Do you want some pie?” the other day, it was the last straw.
His first decision was to sense the door opening with a magnet and sensor, which he stuck to the door and frame with hot glue. He then ran a long cable to his desk, where it connected to an ATTiny 85 with a DigiSpark boot-loader. He wrote firmware to simulate special key combinations, which were then registered with his audio routing software Voicemeeter Potato. We presume he isn’t using an external mic, in which case muting might have been easier to accomplish with a hardware switch. All in all, this is a pretty clever and timely hack. Should you be in a similar predicament and want to try this out, he’s published the source code on GitHub.
It sounds like science fiction — and until 2012, the ability to cheaply and easily edit strings of DNA was exactly that. But as it turns out, CRISPR/Cas9 gene editing is a completely natural function in which bacteria catalogs its interactions with viruses by taking a snippet of the virus’ genetic material and filing it away for later.
Now, two women have won the 2020 Nobel Prize in Chemistry “for developing a method for genome editing”. Emmanuelle Charpentier and Jennifer Doudna leveraged CRISPR into a pair of genetic scissors and showed how sharp they are by proving that they can edit any string of DNA this way. Since Emmanuelle and Jennifer published their 2012 paper on CRISPR/Cas9, researchers have used these genetic scissors to create drought-resistant plants and look for new gene-based cancer therapies. Researchers are also hoping to use CRISPR/Cas9 to cure inherited diseases like Huntington’s and sickle cell anemia.
The discovery started with Emmanuelle Charpentier’s investigation of the Streptococcus pyogenes bacterium. She was trying to understand how its genes are regulated and was hoping to make an antibiotic. Once she teamed up with Jennifer Doudna, they found a scientific breakthrough instead.
Emmanuelle Charpentier was born December 11th, 1968 in Juvisy-sur-Orge, France. She studied biochemistry, microbiology, and genetics at the Pierre and Marie Curie University, which is now known as Sorbonne University. Then she received a research doctorate from Institut Pasteur and worked as a university teaching assistant and research scientist. Dr. Charpentier is currently a director at the Max Planck Institute for Infection Biology in Berlin, and in 2018, she founded an independent research unit.
Upon completion of her doctorate, Dr. Charpentier spent a few years working in the States before winding up at the University of Vienna where she started a research group. Her focus was still on the bacteria Streptococcus pyogenes, which causes millions of people to suffer through infections like tonsillitis and impetigo each year. It also causes sepsis, which officially makes it a flesh-eating bacterium.
All this ongoing forced togetherness is great, but sometimes you just need to be able to pretend you’re alone so you can get some work done. So, how do you keep family members out of your home office? Our own [Bob Baddeley]’s free/busy indicator is about as simple as it gets.
