Timeframe: The Little Desk Calendar That Could

April 16, 2023 by Matthew Carlson 7 Comments

Usually, the problem comes before the solution, but for [Stavros], the opposite happened. A 4.7″ E-Ink screen with integrated battery management and ESP32 caught his eye, and he bought it and started thinking about what he wanted to do with it. The Timeframe is a sleek desk calendar based around the integrated e-ink screen.

[Stavros] found the device’s MicroPython support was a little lackluster, and often failed to draw. He found a Platform.io project that used an older but modified library for driving the e-ink display which worked quite well. However, the older library didn’t support portrait orientation or other niceties. Rather than try and create something complex in C, he moved the complexity to a server environment he knew more about. With the help of CoPilot, he got some code that would wake up the ESP32 every half hour, download an image from a server, and then display it. A Python script uses a headless browser to visit Google Calendar, resize the window, take a screenshot, and then upload it.

The hardest part of the exercise was getting authentication with Google working reliably. A white sleek 3D printed case wraps the whole affair in an aesthetically pleasing shell. So far, this has been a great story of someone building something for themselves and using their strengths. Where’s the hack?

The hack comes when [Stavros] tried squeezing his calendar into a case that was too tight and cracked the screen. Suddenly a large portion of the screen wouldn’t draw. He turned what was broken into something new by mapping out the area that didn’t draw and converting the Python to draw weather information with Pillow rather than screenshot a webpage: clever reuse and a way to make good out of a bad accident.

The code is up on GitLab, and the 3D files for the case are available on Printables. You can also find the project on Hackaday.io, as it was an entry into our recently concluded Low-Power Contest. Unfortunately, while the Timeframe is pretty power efficient, it doesn’t last as long as this calendar with a 50-year battery life.

Internet Of Washing Machines Solves An Annoyance

April 15, 2023 by Al Williams 56 Comments

[Laurence Tratt]’s washing machine blew up, so he sprung for a brand new model with all the bells and whistles. Of course, these days, that means it has an Internet connection and an API. While we’re not quite convinced our washing machine actually needs such a thing, at least [Laurence] is making the most of it by creating an interface to the washer’s API that provides a handy countdown on the computer.

Honestly, there was one other option. The washer’s phone app — that sounds funny when you say it out loud — will notify you when the clothes are done. But it doesn’t provide a countdown, and it seems to regularly log you off, which means you don’t get the notifications anymore. You can see the minimal interface in the video below.

The exact combination of curl, jq, and pizauth probably won’t help you unless you have the same washer. On the other hand, it is a good example of how to hit some alien API and work out the details. Any API that uses OAuth2 and JSON won’t look too different. Speaking of OAuth2, that’s the purpose of the pizauth program — which, it turns out, [Laurence] is the author of.

Of course, you can refit an old washing machine to do this, too. We are more likely to steal the machine’s motor than to want to talk to it but to each their own!

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A white, house-shaped clock with the words "TEMPUS NECTIT" written in faux Roman script in black on a strip of silver at the base of the "roof." a white power cord extends from the left of the enclosure, and the center of the clock is a 22 pin knitting machine wheel with one pin covered in silver metalic. A white plastic peg extends from the bottom right of the enclosure to hold the feedstock yarn.

Tempus Nectit, A DIY Knitting Clock With Instructions

April 5, 2023 by Navarre Bartz 1 Comment

We’re no strangers to unusual clocks here at Hackaday, and some of our favorites make time a little more tangible like [Kyle Rankin]’s knitting clock.

Inspired by our coverage of [Siren Elise Wilhelmsen]’s knitting clock, [Rankin] decided to build one of his own. Since details on the build from the original artist were sparse, he had to reverse engineer how the device worked. He identified that a knitting clock is essentially a knitting machine with a stepper motor replacing the hand crank.

Using a Raspberry Pi with an Adafruit motor hat connected to a stepper motor and a 3D printed motor adapter, [Rankin] was able to drive the knitting machine to do a complete round of knitting every twelve hours. By marking one of the knitting pegs as an hour hand, the clock works as a traditional clock in addition to its year-long knitting task. [Rankin] says he still has some fine tuning to work on, but that he’s happy to have had the chance to combine so many of his interests into a single project.

If you’re looking for more knitting hacks, check out this knitted keyboard instrument or a knitted circuit board.

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A shot of the underside of a "One Fast Cat" cat wheel with an installed ESP8266 and hall effect sensors attached to the base.

Spy On Your Cat To Make Sure It Gets Its Paws In

April 2, 2023 by Abe Connelly 8 Comments

[Scott Cutler] has a young cat, [Cygnus], that loves to run on a cat wheel and [Scott] had some some important questions about [Cygnus]’s usage of the cat wheel like, how often it’s used, what direction is preferred and how fast does [Cygnus] go. To answer these questions, [Scott] put some telemetry sensors onto the cat wheel and analyzed the results.

An ESP8266 microcontroller and two 3144E hall effect modules were used to sense eight magnets glued onto the outer housing of a “One Fast Cat” cat wheel. [Scott] installed the ESP8266 and hall effect modules onto the base support for the wheels, using 3D printed brackets to secure them.

For the software side, the ESP8266 attaches an interrupt handler whenever a sensor passes by, recording a window of three previous measurements for valid sample determination and, if accepted, uses the time between samples to infer direction and speed. The ESP8266 connects to a pre-configured local WiFi network and has a telnet interface to extract stored log information, in the form of JSON data.

[Scott] has some nice graphs and other data visualizations on [Cygnus]’s usage, including a preference for running at 3 AM, achieving a maximum speed of 14 mph and an average of 4 seconds per run. The source is available on GitHub and the STL files are available embedded in [Scott]’s write-up. We’ve featured cat exercise trackers before with a giant hamster wheel outfitted with a Raspberry Pi and it’s nice to see some options that allow for a retrofit option in addition to a complete DIY solution.

Enjoy An Open-Source Espresso

March 24, 2023 by Bryan Cockfield 15 Comments

One of the core principles of the open-source movement is that anyone who wants to build on a piece of work, in whatever way they want, is easily able to. With source code freely available, the original project can be expanded upon, modified, updated, or simply looked at and used as inspiration. Usually we think about this in the realm of software freedom, but hardware is an important component as well. And not just electronics hardware, either. [Norm] demonstrates this espresso machine which was built on these open-source foundations.

The project takes some inspiration from the open-source Gaggiuino project, which was another build that modified an entry-level espresso maker with finer control over temperature and pressure. [Norm] was not willing to sacrifice his espresso machine for this cause, though, which is how this machine with its cobbled-together hardware came to be. An older machine with some worn parts was sacrificed to the coffee gods instead, making use of its pumps, boiler, and a few other bits of hardware especially from the hydraulics system. The software control is built around the Gaggiuino project, and includes a custom control board for user interface.

Right now the coffee maker does indeed work, but [Norm] hopes to make some improvements to the device including adding an enclosure of some sort, both to prevent accidental contact with the boiler and to give it a sleek, professional look. We kind of like it the way it is, while acknowledging that it isn’t quite ready for commercial production like this. It has a similar industrial feel as this espresso machine we featured a few years ago that is made out of old engine components.

Ondol: Korean Underfloor Heating

March 23, 2023 by Dave Rowntree 49 Comments

One of the many aspects of the modern world we often take for granted is the very technology that keeps our accommodation at a habitable temperature. Examples of this include centralized heating systems using hot-water circulation, or blown air ducted to multiple rooms from a central furnace. Certainly in Europe, once the Romans shipped out, and before the industrial revolution, we were pretty cold unless someone lit a fire in the room. Every room. But not in Korea. The Ondol heating principles have been used constantly from about 5000 BC to only a few decades ago, keeping your average Korean countryman nice and toasty.

Having said that, the sophistication has improved a bit. Initially, the idea was to simply heat up a bunch of rocks in the fire, and bring them indoors, but Ondol quickly became part of the building itself. As will be seen from the video embedded below, the house sits on top of an elaborate double stack of serpentine channels, that circulate the hot combustion products from the furnace as thoroughly as possible, slowing down the gases and allowing their heat to transfer into the structure of the floor, and then radiate into the space above. It does bear more than a passing resemblance to the Roman hypocaust system, ruined examples of which can be found all over the UK and Europe. The skill demonstrated in the video is considerable, but must surely be an expensive build reserved for the most culturally aware Koreans who wish to live in simpler (and less hectic) locations in their country.

Maybe for the vast majority of us, this kind of thing is not viable, and we’re more likely to benefit from a more centralized approach, perhaps using waste heat from data centers or geothermal activity. (See: Iceland)

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Smart Occupancy Sensor Knows All

March 23, 2023 by Bryan Cockfield 32 Comments

In the last few decades, building engineers and architects have made tremendous strides in improving the efficiency of various buildings and the devices that keep them safe and comfortable to live in. The addition of new technology like heat pumps is a major factor, as well as improvements on existing things like insulation methods and building materials. But after the low-hanging fruit is picked, technology like this smart occupancy sensor created by [Sina Moshksar] might be necessary to help drive further efficiency gains.

Known as RoomSense IQ, the small device mounts somewhere within a small room and uses a number of different technologies to keep track of the number of occupants in a room. The primary method is mmWave radar which can sense the presence of a person up to five meters away, but it also includes a PIR sensor to help prevent false positives and distinguish human activity from non-human activity. The device integrates with home automation systems to feed them occupancy data to use to further improve the performance of those types of systems. It’s also designed to be low-cost and easy to install, so it should be relatively straightforward to add a few to any existing system as well.

The project is also documented on this GitHub page, for anyone looking to build a little more data into their home automation system or even augment their home security systems. We imagine that devices like this could be used with great effect paired with a heating device like this, and we’ve also seen some other interesting methods of determining occupancy as well.

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