They’re all running Raspbian and boot directly into Chromium with a clean profile every time. The Pis are otherwise completely locked down and accessible only through SSH. A dedicated WiFi network and whitelisted web access help keep them secure. The Pis reboot after five minutes of inactivity which erases all login credentials and bookmarks.
These terminals are scattered throughout the library. Those closest to the front desk have their Pi in a VESA mount on the back of the monitor. The others are locked up in cabinets so they don’t get pinched by the patrons. Library budgets are lean enough already. [viking–] was able to get management sign-off for the project by building a single prototype to show the simplicity of the system and the projected cost savings. Thanks to a couple of cron jobs, the Pis shut the monitors down every night, saving hundreds of dollars per year.
It’s made of 2mm thick sheet metal and features accents made of merri, a rather nice blood wood native to Western Australia. [George] of Make It Extreme built this mailbox primarily for remote control access, the idea being that each of his family members would have a key fob remote to open it. There’s an input panel under the lid in case someone loses or forgets their remote.
The setup is simple. That 12V solar panel under the address number is connected to a solar charge controller and charges a small battery. Pushing the A button on the key fob remote triggers the latch to slide over, unlocking the door. A push of the B button turns on an interior light for late-night mail collecting. The tube on the side is for leaflets and other postal miscellany. Now, the coolest feature: when mail passes through the slot, it lets [George] know by calling his cell phone. Check out the build/demo video after the break.
How do you earn a place in a flower festival with a handful of Arduinos and a 3D printer? By building a water curtain that draws flowers. That’s exactly what Tecnoateneu Vilablareix, a hacking community in Spain did. They built this project specifically for Temps de Flors, a popular annual gathering in Girona, Spain. More than just a flower festival, the event opens gardens and courtyards of culturally importance to the general public that are closed the rest of the year.
The water curtain uses four Arduino Nanos to control the valves, which work in pairs to draw flowers, words, and patterns. A Mega provides a wifi connection to receive commands. Over 16 continuous days worth of print time went into the 128 valves and 64 nozzles that make up the water curtain. It took the group around 24 iterations to get the valve design just right—they have to be able to shut off quickly.
There’s an eight-video playlist after the break and a special video that shows how much we love pandering. Most of the ones in the playlist are quite short and demonstrate the final version of the water curtain. Others show the valve testing. The last is a time-lapse of the group setting it up at the festival. If you’re in the area, the festival runs until May 15th.
The design seems pretty simple, although the plans leave a bit of explanation to be desired. Inside the billboard are canisters of Lurex 3, a lactic acid-based mosquito attractant that is available pretty cheaply on Amazon. The lactic acid mimics the scent of human sweat and is released outward to distances up to 4km (2.5 miles) in a fine mist along with CO₂. Together, the Lurex and CO₂ act like a sweaty, mouth-breathing human beacon to lure mosquitoes into the billboard, where they become trapped and are doomed to die of dehydration. Continue reading “This Billboard Kills Zika Mosquitoes”→
Hollywood would have you believe that tornadoes are prevalent in the Midwest. We’re much more likely to see hail in the springtime—balls of slushy ice that pelt our roofs and dimple our cars. [Dr. Ian Giammanco] and his wife and fellow scientist [Tanya Brown-Giammanco] have been studying hail at the Insurance Institute for Business and Home Safety’s research lab since 2012. In 2013, their team created over 9,000 artificial hailstones and fired them at a mock-up of a house in the first indoor full-scale hailstorm.
While it would be nice to be able to control hail, the next best thing is mitigating the damage it causes. The better that scientists understand hail, the better materials will become that can withstand its impact. Perhaps someone can perfect a shape-shifting building material and make it resistant to hail.
[Dave] builds custom wooden orreries, which are mechanical models of the solar system. It’s no surprise then that he’s interested in the Antikythera Mechanism—a small geared device discovered off the coast of the Greece in 1900 that is believed to be the first analog computer and one of the oldest known geared systems, built partly to predict the positions of celestial bodies in the solar system as it was understood in ancient Greece.
[Dave] decided to build a wooden version of the Antikythera Mechanism as a proof of concept that it can be done in wood rather than the brass of the original. He also sought to incorporate all the modern theories of the device’s gear train. The entire system is made out of 6mm birch plywood that [Dave] cut by hand on a scroll saw. That’s right — no CNC or lasers here. This has as much to do with replicating the craftsmanship of the original as it does with practicality. Besides, the pitch of the gear teeth is too small to be effectively cut with a laser.
There are no motors, either. The gears are centrally connected to nested brass tubing and the mechanism is actuated with a hand crank. The six pages of forum discussion are worth combing through just to see the pictures of [Dave]’s progress and all of those meticulously hand-cut gears.
It took [Dave] the better part of two years to complete this work of art, and you can see it in motion after the break. With the first version complete, he has begun Mk. II which will feature all of the spiral dials and pointers of the original. If you’re interested in exploring the Antikythera Mechanism further, here is Hackaday’s own in-depth look at it.
[MisterM] is a man after our own heart. He loves to combine the aesthetic of vintage equipment with the utility of new technologies. His latest venture is AlexaPhone, which marries the nearly instantaneous retrieval and computation power of Amazon’s Alexa voice service with the look and feel of a 1970s rotary phone. Best of all, there’s no need to spin the dial and wait for it to go whirring back around. AlexaPhone is ready to take questions as soon as the handset is lifted.
Questions are transmitted through a salvaged USB VOIP phone plugged into the Pi. The user must hang up the receiver in order to trigger the search. Once Alexa has an answer, the audio comes back through a small external amplified speaker with a USB-rechargeable battery. Since the hardware is a bit atypical for Alexa, [MisterM] had a bit of trouble at first trying to query the service with a physical button until he came across this AlexaPi code.
This phone is actually a reproduction of a classic BT Trimphone, which explains the asterisk and octothorpe on the dial. The modern internals meant that [MisterM] could take advantage of the ribbon cable coming off of the receiver hook to trigger the Pi to send the query. Watch [MisterM]’s kids put Alexa through her paces after the break.