Secret Book Light Switch

You enter a study and see a lightbulb hanging on the bookshelf. You try all the switches in the room — nothing is turning it on. Remembering you’re in [lonesoulsurfer]’s home, you realize that you’re going to have to start yanking on every book in sight.

While often associated with the likes of Bat-caves and other complicated hidden passageways, turning a shelved book into a secret switch isn’t complex in its own right. [lonesoulsurfer] is basing their build on one by B.Light Design revolving around a fan switch, some aluminium strips, a block terminal, fishing line, a hinge, and — of course — a book with a dust jacket and something to trigger.

Bend the aluminium into an angle bracket and drill a hole to attach the fan switch — ensuring the whole is small enough to fit behind and not distinguish the book you’re using. Cutting the hinge to the size of the book and screwing a strip of aluminium to it, both this lever and the fan switch’s bracket are then mounted on the shelf. Once a length of fishing twine is tethered to the lever and fitted through the book’s pages to the fan switch — ensuring the line is taut — sliding the dust jacket back onto the book completes the disguised switch!

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Robotic Wood Shop Has Ambitions To Challenge IKEA

Many people got their start with 3D printing by downloading designs from Thingiverse, and some of these designs could be modified in the browser using the Thingiverse Customizer. The mechanism behind this powerful feature is OpenSCAD’s parametric design capability, which offers great flexibility but is still limited by 3D printer size. In the interest of going bigger, a team at MIT built a system to adopt parametric design idea to woodworking.

The “AutoSaw” has software and hardware components. The software side is built on web-based CAD software Onshape. First the expert user builds a flexible design with parameters that could be customized, followed by one or more end users who specify their own custom configuration.

Once the configuration is approved, the robots go to work. AutoSaw has two robotic woodworking systems: The simpler one is a Roomba mounted jigsaw to cut patterns out of flat sheets. The more complex system involves two robot arms on wheels (Kuka youBot) working with a chop saw to cut wood beams to length. These wood pieces are then assembled by the end-user using dowel pegs.

AutoSaw is a fun proof of concept and a glimpse at a potential future: One where a robotic wood shop is part of your local home improvement store’s lumber department. Ready to cut/drill/route pieces for you to take home and assemble.

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Shoot-And-Forget Digital Photo Frame

Digital photo frames these days require you to manage the photos stored on it or the cloud-based service tied to the frame’s manufacturer. [Henric Andersson] realized that he and his wife take a lot of photos but find little time to go through them — like photo albums of days past — and add them to any photo frame-like appliance or service. Since Google photos can do a lot of the sorting for them, he decided to incorporate that into a digital photo frame.

Using his wife’s old Viewsonic 24” 1080p monitor, he cracked it open and incorporated the screen into a 24×16 distressed wood frame — reinforcing it to account for the bulky, built-in power supply with pieces of HDF and a lot of glue. The brains behind this digital photo frame is a Raspberry Pi 3 he received from a friend. To turn the whole on/off, he built a small circuit but it turned out it wasn’t strictly necessary since everything started just fine without it.

While functionally complete, it needed one more addition. A little thing called ‘color temperature calibration’ — aka white balance.

Finding the TCS34725 RGB color sensor by Adafruit — and readily available code for easy integration — [Andersson] puzzled over how to add it to the frame. To disguise it while retaining its effectiveness, he had to glue it to the rear of the frame after drilling a hole in the top piece and sticking a plastic stick through the hole to let light through to the sensor.

To get the photos to display, [Henric Andersson] says all he did was add a few queries to Google Photos and it will display all your relevant photos that have been synced to the service. For a breakdown of that side of this hack, check out his other post with the details.

While Google Photos deftly displays photos of various orientations, sizes, and aspect ratios, we’ve featured a digital photo frame that handles the task a little differently.

No, Cat, This Is Not The Litter Box

Hackaday.io user [peterquinn] has encountered a problem with his recently unruly cat peeing under the dining table. Recognizing that the household cat’s natural enemy is the spray bottle, he built an automatic cat sprayer to deter her antics.

The build is clear-cut: an Arduino Uno clone for a brain, an MG995 servo, PIR sensor, spray bottle, and assorted electronics components. [peterquinn] attached the servo to the spray bottle with a hose clamp — ensuring that the zero position is pointing at the trigger — and running a piece of cabling around the trigger that the servo will tug on. Adding a capacitor proved necessary after frying the first Uno clone, as the servo powering up would cause the Uno to reset.

The code is set up to trigger the servo — spraying the cat twice — once the PIR detects the cat for more than ten seconds. After toying with a few options, [peterquinn] is using a 9V, 2A power supply that works just fine. For now, he hopes the auto-sprayer should do the trick. If it somehow doesn’t work, [peterquinn] has mused that a drastic upgrade to the vacuum may be necessary.

Look Out Nest — Here Comes The WIoT-2

[Dave] is an avid hacker and no stranger to Hackaday. When he decided to give his IoT weather display an upgrade, he pulled out all the stops.

The WIoT-2 is less of a weather station and more of an info center for their house — conveniently located by their front door — for just about anything [Dave] or his partner need to know when entering or exiting their home. It displays indoor temperature and humidity, date, time, garbage collection schedule, currency exchange rates, whether the garage door is open or closed, the hot tub’s temperature, a check in for his kids, current weather data from a custom station [Dave] built outside his house, and the local forecast.

WIoT-2’s display is a Nextion TFT and the brains behind the operation is a NodeMCU 8266. He made extensive use of Blynk to handle monitoring of the various feeds, and will soon be integrating master control for all the networked outlets in the house into the system. He found setting up the hardware to be fairly clear-cut but notes that he cannot have the screen powered on when uploading sketches to the NodeMCU.  He circumvented the problem by adding a latching switch to the screen’s power line.

[Dave] curated a robust explanation of his build that includes tips, tricks, code — and a how-to to boot! If you’re not already starting your own build of this info suite, you may be tantalized by some of his other projects.

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Cloning The Echo Show With A Fabric Wrapped Pi

After seeing an Echo Show in the flesh plastic, [anonteapot] was inspired to create his own take on Amazon’s latest on-ramp to their ecosystem. He had the Raspberry Pi and a touch screen, but not much else. He doesn’t even have a dedicated work area at home, much less something as exotic as a 3D printer to run off a custom case. For this decidedly low-tech build, all that was required tool-wise was a razor blade knife and a screwdriver.

The majority of the device, which he refers to as the PiShow, is made of hand-cut pieces of MDF. In fact, the whole build relied on his ability to neatly cut pieces of MDF with hand tools on his bedroom floor. We wouldn’t suggest such a setup as a general rule, but respect for pushing ahead without so much as a table to work on.

To connect the pieces of MDF, he used angle brackets from the hardware store. These were originally 90 degrees, but he bent them by hand to achieve the angles seen in the final device. He notes that there was no specific angles he was aiming for when putting the box together; he simply wanted something that looked cool and was large enough internally to hold his electronics.

Covering the PiShow is some jersey material that [anonteapot] bought at a local fabric store. It has a little stretch to it so he was able to pull it tight over the MDF frame and keep the wrinkles out. As a general rule we don’t see many projects here at Hackaday that are wrapped in fabric, but we’ve got to admit, it makes for a nice final look.

The trickiest part of the build ended up being the side panels. While the rest of the frame was relatively simple, the sides needed to precisely conform to some fairly complex geometry. Luckily the side panels aren’t actually holding any weight, so he decided to just cut them out of cardboard. There’s a bit of a gap at the top, but he’s going to try and rectify that with a visit from his glue gun soon.

Internally things are sort of just hanging around inside the case, but since this device is never going to move off of the nightstand, it probably doesn’t need to be terribly secure. In truth, getting all the hardware mounted up cleanly with the construction methods available to [anonteapot] would have been a bit tricky anyway.

This is the first time we’ve seen somebody take a swing at replicating the Echo Show, usually we just see people trying to cram the Echo Dot into something else. If the software side is more your thing, be sure to check out this excellent guide on Alexa Skills development by our very own [Al Williams].

Curing A Parrot’s Amnesia With BLEAH

[Dandu] recently wrote in to tell us how he managed to revive his Parrot Flower Power after the manufacturer told him it couldn’t be repaired. To save you the trouble of opening Google in another tab, the Parrot Flower Power is a Bluetooth Low Energy (BLE) “smart” device for your flower pot. Because of course that’s a thing.

A healthy Flower Power connected

When [Dandu] noticed his Flower Power was no longer being detected by his iOS devices, he contacted support who told him that sadly this was a hardware failure and that he should just throw it away. But he had his doubts about this diagnosis as other devices such as his Raspberry Pi could still communicate with it. Upon closer inspection, he realized that the Flower Power didn’t have a name, and could only be contacted by its MAC address directly. Reasoning the lack of a name might be upsetting the “It Just Works” sensibility of his iGadget, [Dandu] started researching if there was some way to get the device to take a new name remotely.

Luckily for our hero, BLE is kind of broken. Searching for a solution to his problem brought him to a blog post by the creator of BLEAH which demonstrated exactly what [Dandu] was looking to do. Following along, it took only a single command to push a new name to the Flower Power’s BLE configuration. With that, his “broken” device was brought back to life. Why the device lost its name, or how to prevent it from happening in the future are questions for another day. [Dandu] will take the win.

If you’re interested in the popular new technology that’s compromising our security in the name of convenience and improved battery life, the rabbit hole starts here.