home hacks

1860 Articles

Simple Wi-Fi Cat Door Solves The Extra Critter Problem, And Nothing More

November 2, 2022 by 11 Comments

Anyone with an outdoor cat in their life knows their propensity for bringing home offerings, in the form of critters in various stages of the process of becoming ex-critters. And anyone with a hacker in their life knows that there’s a tendency to throw technology at this problem. But sometimes, the simplest solutions are the best.

Take this simple stepper-powered cat door lock. For [Jason Winfield], the essential problem with his outdoor cat’s late-night demands for reentry was having to manually unlock the cat door after a quick visual check that no midnight snacks were along for the ride. Such activity tends to make it hard to get back to sleep. One natural reaction to this would be to completely automate the process with machine learning to recognize the offering and deny entry; we’ve seen exactly that before, after all. But recognizing that the disruptive part was the getting up to check bit, [Jason] just whipped up a simple stepper-driven lock with an ESP8266 microcontroller. With a 3D-printed case and a battery pack, and a nearby Wi-Fi camera, the lock denies entry to the cat until he gets a look at it, at which point he simply hits the lock’s webpage to unlock the door. The video below would show the lock in action, except the cat buggered off once it got a whiff of the doings. Cat’s gonna cat.

What we appreciate about this project is its simplicity. It solves the problem with the minimum feature set, which is something we see too little of sometimes. It’s also got some nice ideas, like the non-captive bolt that can be removed to unlock the door if the battery dies. Smart thinking, [Jason], and sweet dreams.

Continue reading “Simple Wi-Fi Cat Door Solves The Extra Critter Problem, And Nothing More” →

Breakers for the system on a DIN rail, with markings like 48V and 24V and 12V and so on on the bottom, and two hefty devices of some kind on the bottom, probably MPTT controllers, with hefty wires running from them.

Low-Voltage DC Network Build Incited By Solar Panels

November 2, 2022 by 56 Comments

Nowadays, some people in Europe worry about energy prices climbing, and even if all the related problems disappear overnight, we’ll no doubt be seeing some amounts of price increase. As a hacker, you’re in a good position to evaluate the energy consuming devices at your home, and maybe even do something about them. Well, [Peter] put some solar panels on his roof, but couldn’t quite figure out a decent way to legally tie them into the public grid or at least his flat’s 220V network. Naturally, a good solution was to create an independent low-voltage DC network in parallel and put a bunch of devices on it instead!

He went with 48V, since it’s a voltage that’s high enough to be efficient, easy to get equipment like DC-DCs for, safe when it comes to legal matters concerned, and overall compatible with his solar panel setup. Since then, he’s been putting devices like laptops, chargers and lamps onto the DC rail instead of having them be plugged in, and his home infrastructure, which includes a rack full of Raspberry Pi boards, has been quite content running 24/7 from the 48V rail. There’s a backup PSU from regular AC in case of overcast weather, and in case of grid power failures, two hefty LiFePO4 accumulators will run all the 48V-connected appliances for up to two and a half days.

The setup has produced and consumed 115kWh within the first two months – a hefty contribution to a hacker’s energy independence project, and there’s enough specifics in the blog post for all your inspiration needs. This project is a reminder that low-voltage DC network projects are a decent choice on a local scale – we’ve seen quite viable proof-of-concept projects done at hackercamps, but you can just build a small DC UPS if you’re only looking to dip your feet in. Perhaps, soon we’ll figure out a wall socket for such networks, too.

Keeping An Eye On Heating Oil

November 2, 2022 by 70 Comments

Energy costs around the world are going up, whether it’s electricity, natural gas, or gasoline. This is leading to a lot of people looking for ways to decrease their energy use, especially heading into winter in the Northern Hemisphere. As the saying goes, you can’t manage what you can’t measure, so [Steve] has built this system around monitoring the fuel oil level for his home’s furnace.

Fuel oil is an antiquated way of heating, but it’s fairly common in certain parts of the world and involves a large storage tank typically in a home’s basement. Since the technology is so dated, it’s not straightforward to interact with these systems using anything modern. This fuel tank has a level gauge showing its current percentage full. A Raspberry Pi is set up nearby with a small camera module which monitors the gauge, and it runs OpenCV to determine the current fuel level and report its findings.

Since most fuel tanks are hidden in inconvenient locations, it makes checking in on the fuel level a breeze and helps avoid running out of fuel during cold snaps. [Steve] designed this project to be reproducible even if your fuel tank is different than his. You have other options beyond OpenCV as well; this fuel tank uses ultrasonic sensors to measure the fuel depth directly.

A wooden table with a puzzle on top of it sits in an off white room with a light wood floor. A red chair sits behind the table and the slats of the rolled away tambour top are visible.

Tambour Table With A Puzzling Secret

November 1, 2022 by 12 Comments

Some people really like puzzles. [Simone Giertz] is one of these serious puzzle lovers and built a transforming table (YouTube) to let her easily switch between puzzles and more mundane tasks, like eating.

While there are commercial solutions out there for game tables with removable tops and simpler solutions like hinged lids, [Giertz] decided to “make it more complicated and over-engineered than that.” A tambour top that rolls out of the way makes this a unique piece of furniture already, but the second, puzzle table top that can be raised flush with the sides of the table really brings this to the next level.

If that wasn’t already enough, the brass handles on the table are also custom made. In grand maker tradition, [Giertz] listened to her inner MYOG (Make Your Own Gnome) and got a lathe to learn to make her own handles instead of just buying some off the shelf.

If you’re less enamored of puzzles, you may want to see how Jigsaw Puzzles are Defeated. If you’re worried about losing pieces, check out these 3D Printed Sliding Puzzles.

Continue reading “Tambour Table With A Puzzling Secret” →

A segmented lamp made of circular slices of plywood. They are arranged as shutters around a long, skinny LED bulb in the center that gives off an incadescent-looking glow. A cord trails off to the left against the grey background.

Plywood Lamp Has Customizable Light Output

November 1, 2022 by 2 Comments

There’s something about light fixtures that attracts makers like moths to a flame. [danthemakerman] wanted something with a more configurable light output and built this Sculptural and Customizable Plywood Lamp.

In his detailed build log, [danthemakerman] describes how he wanted something “sort of like an analog dimmable light.” By using a stack of split plywood donuts hinged on a brass rod, he can vary the output and shape of the lamp. These shutters allow the lamp to go from bright to nightlight without using any electrical dimming components.

The plywood was rough cut on a bandsaw before being turned on a lathe. The light cover sections were then hollowed out with a Forstner bit and split in half. The tricky bit is the overlap of the cut on the hinge side of the shutters. Cutting the piece exactly in half would’ve required a lot more hardware to make this lamp work than what was achieved by patient woodworking.

If you’d like to see more ways to make light fixtures with plywood, check out this Hexagonal Lamp, these Upcycled Plywood and Glass Lamps, or this Laser-cut Sphere Lampshade that Packs Flat.

A transparent blue resin waterfall tabletop with a single wooden leg sits on a grey rug between two grey leather chairs.

Using The Sun To Turn Epoxy Into Furniture

October 29, 2022 by 16 Comments

Epoxy resins have been used to make some pretty cool furniture, but since it’s still a relatively new material, makers are still discovering new techniques to work with resin. [Cam] from Blacktail Studio may be the first person to bend fully cured epoxy using nothing but a form and the power of the sun.

Inspired by a friend’s mishap with an epoxy table left out in the sun too long, [Cam] wanted to see if he could purposely bend an epoxy sheet into an interesting shape. The tabletop was poured in sections to give an ombre look before being planed and given a preliminary surface finish. The epoxy sheet was then clamped onto a form made of kerfed plywood and left in direct sunlight on a 104°F (40°C) day. Once the sheet began to deform in the sunlight, ratchet straps and more clamps were added to conform the sheet to the bending form.

After letting the tabletop relax for a few days, [Cam] finished the surface with lots of sanding and an automotive polishing regimen. The epoxy was then attached to a single zebrawood leg to give a very modern-looking, waterfall-esque table.

More interesting projects with resin you might want to check out are this ocean-themed epoxy nightlight, how to degas epoxy on the cheap, or some techniques for cold casting with resin.

Continue reading “Using The Sun To Turn Epoxy Into Furniture” →

A picture of the JagerMachine consisting of rectangular, desktop sized drink serving machine with a wooden varnish, a 3.5 inch touchscreen on the front face on top and a cavity with a shot glass in it, lit up by blue leds, with liquid pouring into it.

Shoot An Email To Get A Shot

October 17, 2022 by 4 Comments

[_Pegor] wanted to create a shot pouring machine for their friends birthday. Unfortunately, the build wasn’t done in time, but at least the JagerMachine is finished now so that others can use it.

The JagerMachine has a peristaltic pump that moves liquid from a reservoir hidden in the back of the machine to the glass in front. The machine has a 3.5 inch DSI touch screen display for user input and a WS2812B LED ring for creating a small light show when the drinks are served. A 3.3 V to 5 V level shifter is used to power the LED ring and a motor driver module is used to drive the peristaltic pump motor. It looks like there’s a “shot glass detection” feature that uses a 3D printed mini platform with a notch for a magnet so that when a glass is placed on top of it, the hall sensor can detect the presence of the nearby magnet.

Part of the charm of this project is the software stack on the Raspberry Pi that allows for novel interaction, including being able to serve drinks from the receipt of emails. Using the Raspberry Pi as the controlling device allows for this rich set of interfacing options, including easily allowing the ability to drive the LEDs, detect the presence of the shot glass, along with establishing network connectivity. The setup procedures are all documented in the repository for anyone wanting to see how this type of functionality might transfer to their own project.

Drink mixing robots are, of course, a thing. ranging from small and cute to full shelf.