Arc-fault circuit breakers are a boon for household electrical safety. The garden-variety home electrical fire is usually started by the heat coming from a faulty wire arcing over. But as any radio enthusiast knows, sparks also give off broadband radio noise. Arc-fault circuit interrupters (AFCI) are special circuit breakers that listen for this noise in the power line and trip when they hear it. The problem is that they can be so sensitive that they cut out needlessly. Check out the amusing video below the break.
Our friend [Martin] moved into a new house, and discovered that he could flip the breakers by transmitting on the 20-meter band. “All the lights in the place went out and my rig switched over to battery. I thought it was strange as I was certainly drawing less than 20 A. I reset the breakers and keyed up again. I reset the breakers again and did a [expletive] Google search.” Continue reading “Ham Radio Trips Circuit Breakers”
Car lifts used to be a tool reserved for professional mechanics. Times are a-changing though. With the advent of reasonably priced four-post hydraulic lifts, more and more shade tree mechanics are joining the five-foot high club. Installing a lift in a home garage creates a few hazards, though. What happens when a family remotely opens the garage door while there is a car up on the lift? Garage door and lifted vehicle will meet – with expensive and/or dangerous results. [Joe Auman] saw this problem coming a mile away. He built the LiftLocker to make sure it never happens to him.
At its core, LiftLocker is a set of switched extension cords. Two cast-aluminum boxes hide the electronics. One box plugs in-line with the lift. The other box plugs in-line with the garage door opener. Each box includes a Sparkfun Redboard Arduino compatible, an RFM22 433 MHz Radio, and a relay. Input comes from a security system magnetic reed-switch. Both boxes are identical in hardware and code.
Operation is simple. One box and reed switch goes on the lift, the other on the garage door. If the lift is going up, its reed switch will open. The lift’s Arduino detects this and commands its RFM22 to send a signal to the other box on the garage door. Upon receiving this signal, the garage door controller will open its relay, disconnecting power to the garage door opener. Communication is two-way, so if the Lift controller doesn’t hear an ACK message from the garage door controller, everything will shut down. Click past the break to see the system in action.
Continue reading “LiftLocker Keeps Your Lift Safe from Attacking Garage Doors”
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?”
Standing desks are either the best thing since sliced bread, or the fastest way to make your legs tired and get you ridiculed by your coworkers in the bargain. This leads some folks to compromise and make standing desks that can be re-lowered to sitting height when you need to take a break. But now the distance from your desktop to the light source that illuminates it has changed. We can’t have that!
[John Culbertson] came up with a very elegant solution to the “problem”. He made lights that are suspended on pulleys that raise and lower with the desk itself. We’re not sure that you’re in the same situation he is, but we’re sure that you’ll agree that he did a nice job.
Besides the pulley mechanism, the light shades are a work of art. [John] clearly wanted a retro feel, so he used low-voltage lightbulbs, but augmented them with LED strips to pump out the lumens. All in all, there’s a tremendous attention to detail in the project, and it shows.
Disclaimer: your humble author is writing you this missive from a standing desk. Ours is just a regular desk put up on bricks — a temporary solution that’s become permanent. We’re always keeping our eyes out for mechanisms to make the desk convertible, but everything that we’ve seen is either overkill or ridiculously overpriced or both. It’s hard to beat 24 bricks at $0.35 apiece. Anyone have any suggestions?
Of course, with an adjustable desk come the problems of moving your lighting along with it, but [John] has solved that one for us.
At first we laughed at the ridiculously over-the-top fume extraction system this hackerspace built for itself. Then we thought about seriously questionable donation rolls of solder some of the members managed to find and bring in. The kind of roll where the local greybeard assures you that a Californian State Trooper has permission to shoot you if you try to take it into the state, but damn does it solder well. They may be onto something is all we’re saying. But on a serious note, for a communal space like this one, a great air quality plan makes the place a lot more pleasant, if not safer at the same time.
The build uses a regular boost fan for its main suction and pulls the fumes out to a place the members aren’t. Knowing hackerspaces that could be anything from an empty alley to vents on the building’s roof. It’s actually an interesting challenge to solve in a rented space (please share your own solutions for “daylighting” to the outside in the comments).
The frame is made from ducting and dryer hose. Since there aren’t really fittings for this. Most of the joints were designed in OpenSCAD and 3D printed. At each end of the tube a computer fan provides another little boost of airflow. We like the stands to position each end of the hose at the fume source. All of it is powered by a distribution box of their own making with the juice being fed with repurposed Ethernet cables to the fans at the ends of the hose.
It’s a nice build and likely extended the life of a few of the more electronically active members in the space. Especially if the retired radio enthusiasts decide to do their fifty year anniversary garage cleaning and gift upon the space their findings.
Your local hardware store or garden supply center probably has everything you need to install landscape lighting all around your property. What’s a little less likely is coming out of that situation with fewer holes in your wallet than in your yard. And even then, it’s pretty much guaranteed that any off-the-shelf equipment won’t send you a text message when your landscape lighting isn’t working properly. [Mark]’s landscape lighting system does, though!
Powered by a Raspberry Pi, this landscape lighting system has every feature imaginable. It can turn the lighting on at sunset and turn it off at a set or random time later in the evening. There’s a web interface served from the Pi that allows further user control. The Raspberry Pi also monitors the lighting and can sense when one of the lights burns out. When one does, the Pi uses Twillo to send a text message notification.
There’s not many more features we can imagine packing into a setup like this. Of course, if you don’t have a spare Pi around you can probably manage to get the job done with an ESP8266, or even an old-fashioned Arduino.
IoT has become such an polarizing, overused term. But here it is in its essence: [zeroflow] had a thing (his airconditioner) and he needed to put it on the Internet.
For his contribution to this modern vernacular atrocity, he first had to build an IR debugging tool and reverse engineer the signals coming from the air conditioner’s remote. He wrote up a really good summary of the process, and worth reading. He loads up an IR library onto an Arduino and dumps the resulting 32 bits of information to his computer. In a process much like filling in the blanks on a word puzzle, he eventually determines which blocks of the data correspond to the remote’s different buttons.
Next he throws an array of IR LEDS and an ESP8266 onto a bit of protoboard. After writing some code, available on GitHub, he could set the temperature of his room from anywhere on the planet. We take it on faith that [zeroflow] has a compelling reason for doing so.
Bolstered by this success, he didn’t stop there. [Zeroflow] admits to having more than one thing on the Internet. Boom! Internet of things.