Keep In Touch With Grandma, With This Lo-Tech Interface

April 25, 2021 by Jenny List 17 Comments

We have so many options through which to communicate with our friends and relatives during the lockdown, thanks to our smartphones and the number of apps that serve all possible needs. Impressive as they are though, a smartphone is not suitable for everyone. In particular older people can find them less easy to use, and the consequent loss of communication ability is addressed by [Manu] with the Yayagram, described in a thread of Spanish-language Tweets and later the thread was translated into English.

On the top of the box is a microphone with push-to-talk switch, a small thermal printer, and a set of 1/4″ jack sockets with associated jump lead. Each socket corresponds to a relative, and an audio message to that relative can be posted via Telegram simply by speaking into the microphone with the button pressed. Replies are then printed through the thermal printer. Meanwhile behind the scenes is a Raspberry Pi holding it all together.

We like the simplicity of the interface, and who wouldn’t want to ensure that their older relatives were able to keep in touch! But while the jump lead is a neat touch, we hope it’s not too difficult for extremely frail hands. It’s certainly not the first accessibility project for older people that we’ve seen.

Arduino MKR Makes Nespresso Monitoring Easy

April 25, 2021 by Jenny List 23 Comments

Monitoring an appliance with a microcontroller usually follows a well-worn path of diving inside and finding somewhere in the electrical circuitry that can be connected through some kind of interface to a microcontroller. For his Nespresso pod coffee machine, [Steadman] eschewed tearing into the device, and instead chose to monitor the sound it makes. A commodity sound threshold sensor board is hooked up to an Arduino MKR Zero, and this set-up logs coffee consumption. It’s important to note how this generation of Arduino is no longer one of the simple boards of old, instead it sports an RTC and SD card alongside its SAMD21 Cortex-M0+ processor so it is perfect for just such a datalogging project. The coffee data can be saved into a CSV file viewable by a spreadsheet, for which code is provided.

We like this project for its non-invasive simplicity, and we can see that there could be plenty of other similar machines that could benefit from an analagous technique for non-invasive monitoring. While the pages of Hackaday are full of coffee machine projects we see surprisingly few pod coffeemakers, perhaps because our readers are a canny bunch who balk at paying a premium for their caffeine. If you do happen to have a Nespresso machine though, perhaps you’d like some help identifying the capsules.

Heating A Home With Sunlight… And Water

April 22, 2021 by Bryan Cockfield 64 Comments

The sun is a tremendous source of energy, and while photovoltaic panels are an easy way to harvest some of that energy especially now that prices for them are incredibly low, there are plenty of other ways to tap into that free energy as well. [Engelbert] was looking for alternative ways to heat his house since traditional methods were prohibitively expensive, and ended up building a heat exchanger using solar-heated water to cover his home heating needs. (Google Translate from Dutch)

The system uses several large roof-mounted hot water heating panels. The heat captured by them is then pumped into an underground pipe network which is able to warm up a large area of earth in the summer. In the winter, that heat is able to be extracted back out of the earth and used to heat his home. The system includes almost three kilometers of pipe which are buried two meters below grade, so this will probably not be a weekend project, but it still cost much less than the €80,000 to install gas heating in his home.

[Engelbert] is able to use this self-built system to keep his home and another smaller building at a constant 23°C all year. He actually overbuilt the system slightly and has since disconnected almost half of the pipes, but we certainly understand the desire to over-engineer things around here. The only problem he has had is with various government entities that are slow to adopt energy-efficient systems like these. Perhaps the Dutch government can take some notes from the Swiss when it comes to installing geothermal systems like these.

Thanks to [Jero] for the tip!

Smart Pet Feeder Is Well Engineered

April 19, 2021 by Anool Mahidharia 19 Comments

Having pets can sometimes be more demanding than raising kids. Pet owners obviously love and adore their pets, but anything that can be done to reduce their “chores” can be a welcome relief. One big pain point is feeding them at the right time and in the right amount, especially when it comes to cats. As the saying goes, “Dogs have Masters, Cats have Staff! ”

[Sebastian] had had it with his cat [Strachu] nagging him at odd hours for food. Luckily, [Sebastian] is a skilled maker, and his IoT Cat Feeder is not only practical, but also extremely well engineered. He designed and built it from scratch, and the beautiful, final version shows the effort he put in to it. His requirements were quite straightforward. It had to integrate with his home automation system, had to dispense food based on a regular schedule, send him a notification at other times of the day when the feeder detected the cat so he could decide if the cat deserved a special treat or not, and allow him to manually dispense cat food. Finally, he also wanted it to be easy to take apart so he could wash the parts that are in contact with food.

For the electronics, [Sebastian] designed a custom board to hold the ESP12F module and all the other associated parts. Everything, other than the stepper motor is mounted on the PCB. A PIR sensor is used for cat detection. A piezo buzzer lets the cat know that food is ready. A push button can be used to manually dispense food when required. The ESP8266 is flashed with ESPhome which allows control via simple yet powerful configuration files and control them remotely through the Home Assistant addon. If you’re interested in taking a look under the hood, [Sebastian] walks through some of the key code blocks on the ESP side, as well as the various configuration and setting options for the Home Assistant.

But by far the most effort he needed was in getting the mechanical design perfected. He had to go through several rounds of prototype iterations – after all, his cat deserved the very best in feeder design. The basic parts of the design are simple – a stepper motor drives an auger that pushes the cat food from the main container and deposits it in the bowl. Check out the detailed assembly instructions and pictures on his blog. The best part of his design is how easy it is to take it apart the feeder for cleaning. The stepper motor is held in place by a snap fit end piece without using any screws. The main body then just slides out from the top of the electronics box. Check out [Sebastian]’s cat feeder video after the break for details.

If this design makes you hanker to make one for your cat too, head over to his blog post and provide your mail address and [Sebastian] will send all the files for the project.

If your cat isn’t satisfied with dry food nuggets, you probably ought to build this Automated Cat Feeder That Handles Wet Food With Aplomb.

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Weren’t We Supposed To Live In Plastic Houses In The Future?

April 13, 2021 by Jenny List 117 Comments

Futurism is dead. At least, the wildly optimistic technology-based futurism of the middle years of the 20th century has been replaced in our version of their future by a much more pessimistic model of environmental challenges and economic woes. No longer will our flying cars take us from our space-age wonder-homes to the monorail which will whisk us through sparkling-clean cities to our robotised workplaces, instead while we may have a global computer network and voice controlled assistants we still live in much the same outdated style as we did decades ago. Our houses are made from wood and bricks by blokes with shovels rather than prefabricated by robots and delivered in minutes, and our furniture would be as familiar to a person from the 1950s as it is for us.

A Plastic Future That Never Quite Happened

There was a time when the future of housing looked remarkably different. Just as today we are busily experimenting with new materials and techniques in the type of stories we feature on Hackaday, in the 1950s there was a fascinating new material for engineers and architects to work with in the form of plastics. The Second World War had spawned a huge industry that needed to be repurposed for peacetime production, so almost everything was considered for the plastic treatment, including houses. It seemed a natural progression that our 21st century houses would be space-age pods rather than the pitched-roof houses inherited from the previous century, so what better way could there be to make them than using the new wonder material? A variety of plastic house designs emerged during that period which remain icons to this day, but here we are five or six decades later and we still don’t live in them. To find out why, it’s worth a look at some of them, partly as a fascinating glimpse of what might have been, but mostly to examine them with the benefit of hindsight.

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A Fresh E-Ink Newspaper Delivered Every Morning

April 11, 2021 by Matthew Carlson 28 Comments

[Greg Raiz] recently set out to make it easy to read multiple newspapers in the morning over breakfast. Inspired by a similar project, he built an e-ink newspaper that hangs on his wall, delivering fresh news every ten minutes.

The project started with a 32″ Visionect e-ink display configured as a thin client. With a battery life measured in months thanks to the low power electronics, most of the work here was focused on the backend. A docker container running on a local NAS server collects newspapers via freedomforum.org, formats them to fit the aspect ratio of the display, and serves them up. [Greg] is really trying to preserve the design and thought that goes into the front page of each of these publications as traditional newspaper layouts are often designed by hand.

We love the simplicity and the “it-just-works” feel of this project as there are no buttons, wires, or anything that you need to fiddle with. [Greg] points out that it could also be used for other purposes, and we’d love to see a large calendar such as this e-ink calendar or perhaps even a 32″ version of this e-ink laptop. The code for this is on his GitHub with a video after the break.

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Coffee Table Railroad Flips To Hide The Fun

April 10, 2021 by Mike Szczys 13 Comments

The livingroom coffee table has long been a favorite realm of the model railroad. But what to do when you actually want to have coffee? [Peter Waldraff] has come up with a most eloquent answer to the problem by designing a coffee table model railroad capable of turning the world upside down.

This isn’t [Peter’s] first rodeo. In his demo video below he shows off a coffee table train he built 20 years ago using a rectangular layout under glass. This time the circular design means a spherical volume can rotate around two skateboard bearing pivot points, revealing the mountainous scene on one side and the boring old wood table on the other. But what happens to the N-scale train itself when gravity is reversed? There’s a brilliant solution to that!

The frame of the coffee table includes an outer loop for train storage. Before flipping the model upside-down, the train itself is sent to this siding for safe keeping. In an earlier build video we can glimpse the latching mechanism that uses a solenoid and is actuated by a magnet in the center of the table. A clever use of toggle bolts (sometimes known as butterfly anchors for securing things on drywall) has them transfer power to the outer ring of storage track when their spring-loaded arms come in contact with some screw heads on the other side of the gap. The source of the electricity is a rechargeable Makita power tool battery in a hidden chamber within the mountain.

Of course we’ve seen other hideaway coffee table trains like this lovely hand-carved version. But you have to admire how [Peter] managed to incorporate everything into a self contained unit here, without the needing to store a removable cover. If you are someone who wants to always show off your handy work, that’s where a perspex box coffee table design comes into play.

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