A Cool Mist that Dries Your Clothes

This one is both wild enough to be confused as a conspiracy theory and common sense enough to be the big solution staring us in the face which nobody realized. Until now. Oak Ridge National Laboratory and General Electric (GE), working on a grant from the US Department of Energy (DOE), have been playing around with new clothes dryer technology since 2014 and have come with something new and exciting. Clothes dryers that use ultrasonic traducers to remove moisture from garments instead of using heat.

If you’ve ever seen a cool mist humidifier you’ll know how this works. A piezo element generates ultrasonic waves that atomize water and humidify the air. This is exactly the same except the water is stored in clothing, rather than a reservoir. Once it’s atomized it can be removed with traditional air movement.

This is a totally obvious application of the simple and inexpensive technology — when the garment is laying flat on a bed of transducers. This can be implemented in a press drying system where a garment is laid flat on a bed or transducers and another bed hinges down from above. Poof, your shirt is dry in a few seconds.

But individual households don’t have these kinds of dryers. They have what are called drum dryers that spin the clothes. Reading closely, this piece of the puzzle is still to come:

They play [sic] to scale-up the technoloogy to press drying and eventually a clothes dryer drum in the next five months.

We look at this as having a similar technological hurdle as wireless electricity. There must be an inverse-square law on the effect of the ultrasonic waves to atomize water as the water moves further away from the transducers. It that’s the case, tranducers on the circumference of a drum would be inefficient at drying the clothing toward the center. This slide deck hints that that problem is being addressed. It talks about only running the transducers when the fabric is physically coupled with the elements. It’s an interesting application and we hope that it could work in conjunction with traditional drying methods to boost energy savings, even if this doesn’t pan out as a total replacement.

With a vast population, cost adds up fast. There are roughly 125 M households in the United States and the overwhelming majority of them use clothes dryers (while many other parts of the world have a higher percentage who hang-dry their clothing). The DOE estimates $9 billion a year is spent on drying clothes in the US. Reducing that number by even 1/10th of 1% will pay off more than tenfold the $880,000 research budget that went into this. Of course, you have to outfit those households with new equipment which will take at least 8-12 years through natural attrition, even if ultrasonics hit the market as soon as possible.

Continue reading “A Cool Mist that Dries Your Clothes”

How Many Watts Are You Using?

One of the best smart home hacks is implementing an energy monitor of some kind. It’s easy enough to say that you’re trying to save energy, but without the cold hard data, it’s just talk. Plus, it’s easy and a great way to build up something DIY that the whole family can use.

[Bogdan] built up a simple whole-apartment power monitor from scratch over the weekend, and he’s been nice enough to walk us through the whole procedure, starting with picking up a split-core CT sensor and ending up with a finished project.

The brains of his project are an ESP8266 module, which means that he needed to adapt the CT sensor to put out a voltage that lies within the chip’s ADC range of 0 V to 3.3 V. If you’re undertaking an energy monitor project, it’s as easy as picking the right burden resistor value and then shifting the ground-centered voltage up by 1.6 V or so. We say it’s easy, but it’s nice to have a worked example and some scope shots. The microcontroller reads the ADC frequently, does a little math, and you’re done. Continue reading “How Many Watts Are You Using?”

The Internet of Rice Cookers

You’d be forgiven for thinking this was going to be an anti-IoT rant: who the heck needs an IoT rice cooker anyway? [Microentropie], that’s who. His rice cooker, like many of the cheapo models, terminates heating by detecting a temperature around 104° C, when all the water has boiled off. But that means the bottom of the rice is already dried out and starting to get crispy. (We love the crust! But this hack is not for us. This hack is for [Microentropie].)

So [Microentropie] added some relays, a temperature sensor, and an ESP8266 to his rice cooker, creating the Rice Cooker 2.0, or something. He tried a few complicated schemes but was unwilling to modify any of the essential safety features of the cooker. In the end [Microentropie] went with a simple time-controlled cooking cycle, combined with a keep-warm mode and of course, notification of all of this through WiFi.

There’s a lot of code making this simple device work. For instance, [Microentropie] often forgets to press the safety reset button, so the ESP polls for it, and the web interface has a big red field to notify him of this. [Microentropie] added a password-protected login to the rice cooker as well. Still, it probably shouldn’t be put on the big wide Internet. The cooker also randomizes URLs for firmware updates, presumably to prevent guests in his house from flashing new firmware to his rice cooker. There are even custom time and date classes, because you know you don’t want your rice cooker using inferior code infrastructure.

In short, this is an exercise in scratching a ton of personal itches, and we applaud that. Next up is replacing the relays with SSRs so that the power can be controlled with more finesse, adding a water pump for further automation, and onboard data logging. Overkill, you say? What part of “WiFi-enabled rice cooker” did you not understand?

A Smart Switch Board For The ESP8266

With a plethora of IoT projects and inexpensive commercial smart light fittings and mains switches appearing, you might be forgiven for thinking that another offering in this crowded marketplace would be superfluous. But there is always room for improvement in any field, and in this particular one [Xose Pérez] has done just that with his Espurna board.

This board is a very well executed ESP8266 mains relay, with an on-board mains power supply and power monitoring. It was designed with his Espurna (“Spark” in Catalan) custom firmware in mind, which offers support for Alexa, Domoticz, Home Assistant and anything that supports MQTT or HTTP REST APIs.

Best of all, it’s a piece of open source hardware, so you can download everything you need from his GitHub repository to create your own. For the ultimate in convenience you can even order the PCB ready-made from OSH Park.

As a demonstration of the Espurna board in a real application, he’s produced a smart socket project neatly enclosed in a wall-wart style box with an inbuilt Euro style plug and socket.

We’ve featured [Xose]’s work several times before here at Hackaday, he’s something of an IoT wizard. Most recently there was his work with Alexa and the ESP8266, but before that was his MQTT LED array for his laundry monitor.

PassivDom: Mobile Homes for Millenials

In many parts of the world, living in a trailer has gained a social stigma. We’re talking about a rectangular building placed on three wheels and towed to your preferred plot of land. It’s going to take a lot to break that social stigma, but this is a pretty sweet attempt.

PassivDom is an off-grid home. It sidesteps the electrical grid as well as water and sewer service. It’s marketed as utilizing revolutionary breakthrough in wall insulation which they claim makes it very easy to heat and cool. In addition to this self-sustaining angle, it taps into the tiny home movement with a footprint of just 36 m2 (4 m by 9 m; about 118 390 ft2 or 13′ by 30′).

For this to make sense you really need to get the “Autonomous” model, the only one that is designed for “off-grid” living and comes with solar panels and battery storage plus water storage and purification. That’ll set you back 59,900 € (about $63,461 USD) but hey, it does come with “high quality minimalistic furniture” which the best way we can think of to serve Ikea nesting instinct without saying the brand name. Yep, this ticks all the “marketing to millennials” boxes. We’re kind of surprised it’s not doing crowdfunding.

So where’s the hack? Obviously this is a hard sell at 1,664 €/m($538 $163/ft2). A project of this size and scope is well within the purview of a single, motivated hacker, and arguably a weekend project for a well-skilled team from a hackerspace. Tiny Houses started as a build-it yourself so that’s already solved. We’ve seen what it takes for hackers to add solar to their RVs, and experiments in home-built power walls. Water storage and purification is already solved and quite affordable at the home store.

Has anyone built their own off-grid tiny house? If so, let us know what went into it. If not, what are you waiting for?

Google Calendar Interface for Your Internet of Lawns

If you live somewhere where summers are hot and dry, you can instantly tell which homes don’t have automatic sprinklers installed. Or they may have them installed, but like the blinking “12:00” on that VCR of yore, the owners may not have mastered the art of programming the controller. To be fair, the UI on most residential irrigation controllers is a bit wanting, which is the rationale behind letting Google Calendar tell your sprinklers when it’s time to water.

Granted, someone who is mystified by setting a digital clock is not likely to pull off [ClemRz]’s build. It’s still pretty simple stuff, though, centered around an ESP8266 as it is. And calling the result an “irrigation system” is a little bit of a stretch, given that it could only support a single zone with a solenoid valve harvested from a defunct sprinkler timer. But as a proof-of-concept, or to water a small area, it hits all the marks. The ESP8266 drives the latching solenoid valve through an H-bridge chip after reading your Google Calendar and looking for upcoming events to open or close the valve. The Google Script and the ESP8266 code default to failsafe so that a mistake doesn’t leave the valve open and run up your water bill or drain your well.

It’s easy to see how this can be expanded to control a multi-zone irrigation system and support a smartphone UI for instant control of the valves. Overrides based on weather forecasts would be a nice feature too. Or you could just read the soil moisture levels directly with backscatter sensors.

Hackaday Prize Entry: WiFi In Wall Switches

The Internet of Things and Home Automation are the next big thing, even though we’ve had X10 switches and controllers for forty years. Why the sudden interest in home automation? Cheap microcontrollers with WiFi, ZigBee, and Z-wave, apparently. For this Hackaday Prize entry, [Knudt] is building a WiFi switch, meant to be retrofitted into any Euro wall switch.

There are three parts of [Knudt]’s WiFi wall switch, each of them with different requirements. The top layer is the switch itself and a small OLED display. These switches are really two small capacitive switches, which means there’s no reason to go through the work of sourcing a proper mechanical switch. Good thinking, there. The second layer of this contraption is basically an ESP8266, providing all the logic for this wall switch. The bottom layer is a bit more interesting, housing the 110-230V input, with a Triac or relay. This is where the fun, burny stuff happens.

Right now, you can go down to your local home supply store and simply buy a device like this. History has shown that’s a terrible idea. With home automation cloud services shutting down and security vulnerabilities abound, a DIY or Open Source home automation project really is the best idea. That makes [Knudt]’s project a great entry for the Hackaday Prize.