Frustration is tough to deal with. When driven to the point of tears it’s sometimes a short step to lashing out irrationally. Focus in these situations helps, channeling your frustration into something useful. [Yi-Fei Chen] has done that — quite literally — by designing a gun that fires her shed tears.
The gun’s design manifested following a strenuous midterm presentation. Her insistent tutor drove her to tears as frustration clashed with the deep cultural values of her native Taiwan which prevented her from speaking up against authority.
A silicone cup resting against her cheek collects the tears which flow into a chamber of the gun to be frozen. Removing the safety slide preps the round to be fired by the pressure plate trigger on the gun’s rear. It’s simple and it works — tutors beware.
Continue reading “Tear Gun Transmutes Emotions Into Firepower”
In Texas — at least around Houston — we don’t have basements. We do, however, have bilges. Both of these are subject to taking on water when no one is paying attention. A friend of mine asked me what I thought of an Instructable that showed how to make a water sensor using a few discrete components. The circuit would probably work — it relied on the conductivity of most water to supply enough current to a bipolar transistor’s base to turn it on.
It is easy to overthink something like this, so I told my friend he should go with something a little more old-fashioned. I don’t know the origin of it, but it is older than I am. You can make a perfectly good water detector with things you probably already have around the house. My point isn’t that you should (or shouldn’t) construct a homemade water sensor. My point is that you don’t always need to go to the high-tech solution.
Continue reading “Detecting Water With and Without Headaches”
How hot is the water coming out of your tap? Knowing that the water in their apartment gets “crazy hot,” redditor [AEvans28] opted to whip up a visual water temperature display to warn them off when things get a bit spicy.
This neat little device is sequestered away inside an Altoids mint tin — an oft-used, multi-purpose case for makers. Inside sits an ATtiny85 microcontroller — re-calibrated using an Arduino UNO to a more household temperature scale ranging from dark blue to flashing red — with additional room for a switch, while the 10k ohm NTC thermristor and RGB LED are functionally strapped to the kitchen faucet using electrical tape. The setup is responsive and clearly shows how quickly [AEvans28]’s water heats up.
Continue reading “How Hot is Your Faucet? What Color is the Water?”
[Adam] over at Makefast Workshop writes about some of the tests they’ve been running on their 3D printer. They experimented with pausing a 3D print midway and inserting various materials into the print. In this case, sand, water, and metal BBs.
The first experiment was a mixture of salt and water used to make a can chiller for soda or beer (the blue thing in the upper right). It took some experimentation to get a print that didn’t leak and was strong. For example, if the water was too cold the print could come off the plate or delaminate. If there was too much water it would splash up while the printer was running and cause bad layer adhesion.
They used what they learned to build on their next experiment, which was filling the print with sand to give it more heft. This is actually a common manufacturing process — for instance, hollow-handled cutlery often has clay, sand, or cement for heft. They eventually found that they had to preheat the sand to get the results they wanted and managed to produce a fairly passable maraca.
The final experiment was a variation on the popular ball bearing prints. Rather than printing plastic balls they designed the print to be paused midway and then placed warmed copper BBs in the print. The printer finished its work and then they spun the BB. It worked pretty well! All in all an interesting read.
[Ken Rumer] bought a new house. It came with a troublingly complex pool system. It had solar heating. It had gas heating. Electricity was involved somehow. It had timers and gadgets. Sand could be fed into one end and clean water came out the other. There was even a spa thrown into the mix.
Needless to say, within the first few months of owning their very own chemical plant they ran into some near meltdowns. They managed to heat the pool with 250 dollars of gas in a day. They managed to drain the spa entirely into the pool, but thankfully never managed the reverse. [Ken] knew something had to change. It didn’t hurt that it seemed like a fun challenge.
The first step was to tear out as much of the old control system as could be spared. An old synchronous motor timer’s chlorine rusted guts were ripped out. The solar controler was next to be sent to its final resting place. The manual valves were all replaced with fancy new ones.
Rather than risk his fallible human state draining the pool into the downstairs toilet, he’d add a robot’s cold logical gatekeeping in order to protect house and home. It was a simple matter of involving the usual suspects. Raspberry Pi and Arduino Man collaborated on the controls. Import relay boards danced to their commands. A small suite of sensors lent their aid.
Now as the soon-to-be autumn sun sets, the pool begins to cool and the spa begins to heat automatically. The children are put to bed, tired from a fun day at the pool, and [Ken] gets to lounge in his spa; watching the distant twinkling of lights on his backyard industrial complex.
Anyone who owns their own pool knows it’s not as simple as filling it up with water and jumping in whenever you want. There’s pool covers to deal with, regular cleaning with the pool vacuum and skimmers, and of course, all of the chemicals that have to be added to keep the water safe. While there are automatic vacuums, there aren’t a whole lot of options for automating the pool chemicals. [Clément] decided to tackle this problem, eliminating one more task from the maintenance of his home. (Google Translate from French.)
The problem isn’t as simple as adding a set amount of chemicals at a predetermined time. The amount of chemicals that a pool owner has to add are dependent on the properties of the water, and the amount of time that’s elapsed since the previous chemical treatment, and the number of people who have been using the water, and whether or not the pool cover is in use. To manage all of this, [Clément] used an ORP/Redox probe and a pH probe, and installed both in the filtration system. The two probes are wired to an Arduino with an ethernet shield. The Arduino controls electrically actuated chemical delivery systems that apply the required amount of chemicals to the pool, keeping it at a nice, healthy balance.
Continue reading “Home Pool Added to Home Automation”
The goal for the Citizen Science portion of the Hackaday Prize is to empower people to create their own devices to perform their own analyses For [Adam]’s project, he’s designing a device that measures the health of waterways simply by looking at the light availability through the water column. It’s called PULSE, the Profiling Underwater Light SEnsor, and is able to monitor changes that are caused by algal blooms, suspended sediments, or sewer runoff.
The design of PULSE is a small electronic depth charge that can be lowered into a water column from anything between a research vessel to a kayak. On the top of this sinkable tube is a sensor to measure photosynthetically active radiation (PAR). This sensor provides data on light irradiance through the water column and gives a great insight into the health of photosynthesis, marine plant life, and ultimately the health of any aquatic environment.
Measuring the light available for photosynthesis through a water column is great, but PULSE isn’t a one trick pony. On the bottom of the aquatic probe are three sensors designed to measure photosynthesis, dissolved organic matter, and turbidity. These sensors are really just a few LEDs and photodiodes, proving just how much science you can do with simple tools.
The goal of the Citizen Science portion of the Hackaday Prize is to put scientific discovery in the hands of everyone. PULSE is a great example of this: it’s a relatively simple device that can be thrown over the side of a boat, lowered to the bottom or a lake, and hoisted back up again. It’s inexpensive to build, but still provides great data. That’s remarkable, and an excellent example of what we’re looking for in the Hackaday Prize.