How To Build A Fully Offline Smart Home, Or Why You Should Not

January 9, 2024 by Maya Posch 90 Comments

So-called ‘smart home’ appliances and gadgets have become an ever-more present thing the past years, with nary a coffeemaker, AC unit or light bulb for sale today that doesn’t have an associated smartphone app, cloud service and/or subscription to enable you to control it from the beach during your vacation, or just set up automation routines to take tedium out of your busy schedule. Yet as much as [Calvin Wankhede] loves home automation, he’d very much like for it to not stop working the moment his internet connection goes down, or the company running the service goes bankrupt. This is where his journey to create an off-line alternative smart home based around Home Assistant and other (open) software began.

Although Home Assistant (HA) itself has become significantly easier to use, what becomes readily apparent from [Calvin]’s journey is that setting up and managing your own smart home infrastructure is a never-ending project. A project that involves finding compatible hardware that can tie into HA, whether or not without reflashing the firmware, resolving configuration issues and other assorted fun. If you are into this kind of thing, it is of course a blast, and it’s a good feeling when it finally all works.

Unfortunately, interoperability across smart home and similar IoT devices is still a far-off dream, even with the introduction of Thread and Matter (which incidentally are among the worst product names to search for, period), as Matter’s uptake is pretty abysmal. This thus leaves off-line smart homes mostly as the domain of the tech-inclined in search of a hobby.

Hidden Wall-Mount Table Looks Like Hanging Art

December 24, 2023 by Lewin Day 13 Comments

If you live in a compact space, sometimes you have to get creative with your furniture to make the most of it. This wall-hanging table design from [diyhuntress] is perfect for those situations where you need a table, but you don’t want it taking up the whole room when it’s not in use. Plus, it’s kinda stealthy, which makes it even more fun!

The table is a folding design, with a flat wooden top, and an equally-sized supporting leg that goes down to the ground. The other end of the table is supported by a frame on the wall, which also contains several shelves for small objects. The trick is that the table top and support are hinged together, so that they can fold up and sit in front of the shelves, essentially hanging the whole assembly from the wall. Even better, by painting a simple artwork on the support, the whole thing just looks like a decor piece with no clue as to its hidden functionality.

It’s a fun build, and one that you could easily knock out in a weekend with some basic woodworking skills. We’ve featured some other nifty shelf designs before, too. Just remember, too – a neat and tidy space is a boost to your hacker productivity, so don’t rule this out for your own use!

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Cat-o-Matic 3000 Serves Your Feline Masters

December 1, 2023 by Kristina Panos 8 Comments

When you have three cats and three humans, you have one problem: feeding them on a schedule without over or under feeding them. Even if there was only one human in the equation, the Cat-o-Matic 3000 would still be a useful tool.

Essentially, it’s a traffic light for cats — where green means you are go for feeding, and red means the cat was just fed. Yellow, of course, means the cat is either half-full or half-empty, depending on your outlook.

The brains of this operation is an ATmega88PA leftover from another project. There’s a no-name voltage regulator that steps up the two AA cells to 5 volts. Timing comes from a 32 kHz crystal that allows the microcontroller to stay in power-saving sleep mode for long periods of time.

Creator [0xCAFEAFFE] says the firmware was cobbled together from other projects. Essentially, it wakes up once per second to increment the uptime counter and then goes back to sleep. Short-pressing a button shows the feeding status, and long-pressing it will reset the timer.

Wanna make a cat status indicator without electronics? Give flexures a try.

Iowa Demolishes Its First 3D Printed House

November 29, 2023 by Kristina Panos 130 Comments

It sounds like a headline from the future: the weekend before Thanksgiving, a bulldozer came for the first example of a printed home that was supposed to help the housing crisis in the city of Muscatine. Fortunately, it hadn’t been completed and sold yet.

Printing of this first house began in May 2023, and nine more were to be completed by the end of the year. Unfortunately, when tested for compressive strength, the cement mixture this first home was printed out of failed to meet the 5,000 PSI minimum required for the project. Rather than compromise on safety, the parties involved decided to knock it down and start over.

The goal now is to find out why the mixture, which met the strength requirements in laboratory testing, didn’t behave the same on-site. Currently, the plan is to start building the originally-planned second house in the spring, and begin construction on this first site after that.

The project is a collaborative effort between the Community Federation of Greater Muscatine (CFGM), Muscatine Community College, and Alquist 3D. Want to know more about the state of 3D printing when it comes to housing? Check out our handy guide.

Editors Note: The initial post initially indicated that the failed cement mixture contained hemp, but that has since found to be incorrect and the post has been edited accordingly.

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Heat Pump Dryer Explained

November 25, 2023 by Al Williams 98 Comments

Historically, having a washer and a dryer in your house requires “a hookup.” You need hot and cold water for the washer as well as a drain for wastewater. For the dryer, you need either gas or — in the US — a special 220 V outlet because the heating elements require a lot of wattage, and doubling the voltage keeps the current levels manageable. You also need a bulky hose to vent hot moist air out of the house. But a relatively new technology is changing that. Instead of using a heater, these new dryers use a heat pump, and [Matt Ferrell] shows us his dryer and discusses the pros and cons in a video you can below. We liked it because it did get into a bit of detail about the principle of operation.

These dryers are attractive because they use less power and don’t require gas or a 220 V outlet. They also don’t need a vent hose which means they can sit much closer to the wall and take up less space. Heat pumps don’t convert electrical energy into heat like a normal heating element. Instead, it uses a compressor to move heat from one place to another. In this case, the dryer heats the air using the heat pump. That causes water in the clothes to evaporate into the air. The heat pump dryer then uses a second loop to cool the air, condensing the water out so the it can reheat the air and start the whole cycle over again.

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DIY Smart Washing Machine Redesign

November 24, 2023 by Al Williams 17 Comments

[Mellow Labs] wanted a smart washer and built a simple controller. However, he found out after a few weeks it wasn’t working how he wanted. The detergent quit flowing, and he washed clothes with no soap for a week! So, a redesign was in order. You can follow the process and the result in the video below.

A bit of 3D printing, a larger pump, and proper voltage made a big difference. We didn’t see the print files, but unless you have the exact same setup, you’d probably have to customize it anyway. There is a real-time hand-drawn schematic, and the software is probably not hard to pull off the video screen (it is only 18 lines).

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A brown, wooden picture frame with a white matte holds a slightly pixelated photo of gaming miniatures. It is sitting on a wooden table.

A Colorful Take On The E-Ink Photo Frame

November 21, 2023 by Navarre Bartz 7 Comments

Everyone loves sharing photos, and with most pictures being taken on smartphones now, digital frames are more convenient than finding a photo printer. [Wolfgang Ziegler] used an e-ink screen to create a colorful digital picture frame.

Starting with a seven color e-ink HAT he’d forgotten he had, a spare Pi Zero, and analog photo frame, he pieced the parts together into a pretty slick, sunlight readable photo frame. [Ziegler] details how he set up the frame to display new images using the Pimoroni inky library. He set a fifteen minute refresh interval since the color e-ink display takes 30 seconds to refresh to keep it from looking weird too often.

With the holidays coming up, this might make a perfect gift for family that wants to see the latest from your travels without blasting it to the whole internet. We’ve covered a few different options from a lightweight ESP8266 build, to this one that can rotate, and even issues with some of the commercial options.