Not many creatures are as universally despised as mosquitoes, whether it’s the harmless kind that, at worst, makes you miss winter, or the more serious ones that can be a real threat to your health. A satisfying way to deal with them is to send them off with a bang using one of those racket-shaped high voltage metal mesh bug zappers. [lmu34] saw big potential for some additional gamification here, and decided to equip his zapper with a kill counter and matching sound effects.
The initial thought was that there has to be a way to detect when a mosquito hits the mesh, and use that to trigger further events — in [lmu34]’s case play a sound file and increment a counter. After taking the zapper apart and doing a bit of research, he put theory into practice using a Digispark Pro board containing an ATtiny167, the DFPlayer module for playing a set of WAV files, and an ambitious four digit 7-segment display to keep track of the “score”. A new 3d-printed cover provided enough space to house all the components, including a charging circuit as he swapped the original two AAA batteries with a rechargeable one, which gave a bit more power for the display.
Of course, with these operation voltages, it would be difficult to detect activity on the high voltage side more than once, so [lmu34] went with current sensing instead. He distinguishes between two different levels here and maps them as normal kill and monster kill for the big zaps respectively, playing different sounds for each. Have a look at the video after the break for some quick demonstration.
When we first heard of [Ildar Rakhmatulin’s] plan to use OpenCV on a Raspberry Pi to detect mosquitos and then zap them with a 1 watt laser, we thought it was sort of humorous. However, the paper points out that 700,000 people die each year from mosquito bites — we didn’t verify that, but according to the article that’s twice the number of people murdered each year. So the little pests are pretty effective assassins.
It looks as though the machine has been built, at least in a test configuration. A galvanometer aims the death ray using mirrors, and with the low power and lossy mirrors the mosquitos can only be a small distance from the machine — about a foot.
Growing fresh vegetables at home is a popular pastime, even moreso in a year when we’ve all been locked inside. However pests can easily spoil a harvest, potentially putting a lot of hard work down the drain. [Matt] of [DIY Perks] isn’t one to give up his tomatoes without a fight, however, and came up with a solution to protect his plants.
The trick is to take advantage of the mildly conductive slime excreted by snails as they travel along the ground. To protect potted plants, [Matt] places two strips of copper tape around the perimeter of the pot, spaced about a centimeter apart. Each strip is connected to one terminal of a 9 V battery. When a snail attempts to cross the strips, it completes a circuit between the two, and the electrical current that flows irritates the snail, forcing it to retreat.
[Matt] notes that no snails were harmed in the making of the video, and that the solution is far kinder to the slimy critters than poisons or traps. He also goes so far as to demonstrate alternative solutions for garden beds, as well. We’ve more commonly seen [Matt] working with lighting, though it’s great to see he has a bit of a green thumb, too. Video after the break.
If your favorite movie is Ratatouille, now would be a good time to read a different article. Rats on the Galápagos Islands are an invasive species and eradication is underway. This is not a first for the islands, and they are fiercely protected since they are the exclusive home to some species including the distinctive tortoise from which the island derives its name and of course finches. Charles Darwin studied the finches while writing On the Origin of Species. So yeah, we want to keep this island from becoming unbalanced and not disturb the native wildlife while doing it. How do we check all these boxes? Technology! Specifically, hexacopters carrying rat poison.
The plan is simple, drive a truck to a central location, release the hounds drones and fifteen minutes later they come back after flying high above the indigenous wildlife and dropping pest control pellets. The drones save time and labor, making them a workhorse rather than a novelty. This work experience on their resume (CV) could open the door to more dirty work or more wholesome activities. Who is to say that the same drones, the exact same ones, couldn’t deliver plant seeds, or nourishing food to the dwindling species harmed by the rat population explosion.
I’ve got a friend who tells me at every opportunity that soy is the downfall of humanity. Whatever ails us as a society, it’s the soy beans that did it. They increase violent tendencies, they make us fat and lazy, they run farmers out of business, and so on. He laments at how hard it is to find food that doesn’t include soy in some capacity, and for a while was resigned to eating nothing but chicken hot dogs and bags of frozen peas; anything else had unacceptable levels of the “Devil’s Bean”. Overall he’s a really great guy, kind of person who could fix anything with a roll of duct tape and a trip to the scrap pile, but you might think twice if he invites you over for dinner.
So when he recently told me about all the trouble people are having with soy-based electrical wiring, I thought it was just the latest conspiracy theory to join his usual stories. I told him it didn’t make any sense, there’s no way somebody managed to develop a reliable soy-derived conductor. “No, no,” he says, “not the conductor. They are making the insulation out of soy, and animals are chewing through it.”
Now that’s a bit different. I was already well aware of the growing popularity of bioplastics: the PLA used in desktop 3D printers is one such example, generally derived from corn. It certainly wasn’t unreasonable to think somebody had tried to make “green” electrical wiring by using a bioplastic insulation. While I wasn’t about to sit down to a hot bag of peas for dinner, I had to admit that maybe in this case his claims deserved a look.
While most people would be inclined to simply buy the oversized Victor spring-loaded rat traps and call it a day, [Tobie] is a bit more humane. To help remedy his problem while also ensuring that no rats are harmed in the process, he built the Rat Trap 2000.
Self-described as completely over the top, the Rat Trap 2000 lures the rodents into its containment area with apples and corn, securing them inside using a servo-actuated trap door. The door is triggered by an Arduino that monitors the holding pen for movement using an IR sensor. All of the action is captured on video using the web cam on his Eee-PC, as you can see in the very short video below.
This certainly isn’t the most cost-efficient way to control your vermin problems, but if you’ve got some spare parts laying around, why not? It’s far more humane than some of the other rodent control solutions we have seen, and it sure beats living with rats!