Wood-Fired Hot Tub For The End Of The World

August 8, 2020 by Jenny List 13 Comments

It’s one of the idyls of our age, to imagine oneself lounging in a hot tub watching a golden sunset, glass of wine in hand and the love of your life at your side. Along the way though it’s one that’s become diverted from the original, instead of a Scandinavian style wood fired tub in the forest we’re more likely to be thinking of an electric whirlpool spa made from fibreglass, as much a status symbol as a leisure item. It’s refreshing then to see [sirClogg]’s home made hot tub, a simple wooden tub with associated wood stove to heat its water. We can’t wait to step in!

The tub is simplicity itself, being made from softwood planks held together under tension by some steel cables. He admits though that he made a mistake using green wood, as it has now contracted leaving the tub with some gaps. But it’s a simple enough build that he can contemplate dismantling and rebuilding it to correct for that oversight.

Heat meanwhile is provided by a pipe that circulates water from the bottom of the tub through a heat exchanger coil inside a brick-built wood stove adjacent to the tub. The fabrication of the heat exchanger is detailed in the video below, we enjoyed seeing the copper piping filled with salt to ensure it doesn’t collapse when being bent around a five-gallon bucket. It doesn’t get much simpler than this, and the reward of a hot tub must be a sweet one indeed.

For hot tub enthusiast hackers, it’s always worth remembering that the excellent Danish hacker camp BornHack has a hot tub as part of its wellness area.

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You’ve Got Rat!

August 1, 2020 by Jenny List 34 Comments

If you home has never been subject to a rodent invasion then you are fortunate. Our world is full of rats and mice, and despite the best efforts of humanity to keep them at bay it is inevitable that a few will find their way through. For [Marius Taciuc] this became a problem, as his traps needed constant checking to avoid the prospect of a festering rat carcass. His solution? A humane trap equipped with an ESP8266, that notifies him when the rodent is incarcerated.

The tech behind it is about as simple as it’s possible to get, the trap’s door activates a switch, that powers on an ESP8266 module. The ESP’s code simply wakes it up, connects to a wireless network, and sends a query to IFTTT with a call to a service that sends him an email alert. There’s no need to monitor any GPIO lines or have any code running to keep an eye on the trap, it’s all purely a function of the power switch.

The trap itself is interesting, in that it’s a home-made one constructed from soldered copper wire. Sadly there are few details of its construction, but you can see more of it including a live rat inside it, in the video below the break. And if making a trap catches your interest, we can help you there.

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Laser Cutting Your Way To An RGB LED Table

July 24, 2020 by Tom Nardi 19 Comments

You’ve got the RGB keyboard, maybe even the RGB mouse. But can you really call yourself master of the technicolor LED if you don’t have an RGB table to game on? We think you already know the answer. Luckily, as [ItKindaWorks] shows in his latest project, it’s easy to build your own. Assuming you’ve got a big enough laser cutter anyway…

The construction of the table is quite straightforward. Using an 80 watt laser cutter, he puts a channel into a sheet of MDF to accept RGB LED strips, a pocket to hold a Qi wireless charger, and a hole to run all the wires out through. This is then backed with a second, solid, sheet of MDF.

Next, a piece of thin wood veneer goes into the laser cutter. In the video after the break you can see its natural tendency to roll up gave [ItKindaWorks] a little bit of trouble, but when strategically weighted down, it eventually lays out flat. He then uses the laser to blast an array of tiny holes in the veneer, through which the light from the LEDs will shine when it’s been glued over the MDF. A few strips of plastic laid over the strips serve both to diffuse the light and support the top surface.

The end result is truly gorgeous and has a very futuristic feel. Assuming you’ve got the equipment, it’s also a relatively simple concept to experiment with. It’s yet another example of the unique construction techniques possible when you add a high-powered laser to your arsenal.

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A Portable Home Air Quality Meter With The ESP32

July 20, 2020 by Lewin Day 19 Comments

Around the world, rolling pandemic lockdowns have left many working from home. [kn100] is in just such a predicament, and while spending nearly 24 hour a day in a residential flat, got wondering about air quality. Thus, it was time to build some gear to keep an eye on things!

Grafana may require a database and some work to set up, but the results are to die for.

The build consists of an ESP32 hooked up to a Bosch BME680 air quality sensor. It measures pressure, temperature, humidity and gas resistance, and then with a closed source library, uses this to calculate an “Air Quality Index” as well as estimate CO2 and VOC levels in the air. Data is passed from the ESP32 over MQTT to a Raspberry Pi. This runs Mosquitto for handling the MQTT queries, saving the data in an Influxdb instance. Grafana is then used to query this database and produce attractive graphs of the data.

It’s a build that not only helps keep an eye on things in the flat, but is great practice for building solid Internet of Things devices with top-notch data visualisation. We’ve talked about how to do this before, too – so if you need this capability in your life, there’s no excuse not to get hacking!

Home Monitoring, Without All The Sensors

July 17, 2020 by Bryan Cockfield 15 Comments

Smart homes come with a lot of perks, not least among which is the ability to monitor the goings-on in your home, track them, and make trends. Each piece of monitoring equipment, such as sensors or cameras, is another set of wires that needs to be run and another “thing” that needs to be maintained on your system. There are sometimes clever ways of avoiding sensors, though, while still retaining the usefulness of having them.

In this build, [squix] uses existing sensors for electricity metering that he already had in order to alert him when his oven is pre-heated. The sensor is a Shelly 3EM, and the way that it interfaces with his home automation is by realizing that his electric oven will stop delivering electricity to the heating elements once it has reached the desired temperature. He is able to monitor the sudden dramatic decrease in electricity demand at his house with the home controller, and use that decrease to alert him to the fact that his oven is ready without having to install something extra like a temperature sensor.

While this particular sensor may only be available in some parts of Europe, we presume the idea would hold out across many different sensors and even other devices. Even a small machine learning device should be able to tell what loads are coming on at what times, and then be programmed to perform functions based on that data.

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Home Automation Covers Everything

July 13, 2020 by Bryan Cockfield 29 Comments

When starting out on a project, it’s accepted best practice to try to avoid feature creep. Of course, we can’t all say that we follow this guideline completely every time. In fact, sometimes it can get away from us, and in rare situations it might actually turn out pretty well. That appears to be what happened with [superczar]’s home automation project which now covers basically everything possible in home automation.

The build started in 2013, so we assume that features have been added periodically and that the system wasn’t designed and built all in one furious weekend. Either way, though, it covers a lot: lights, switches, media players in several rooms, includes sensors and logging for temperature, smoke, fire, and power, supports a number of cameras, the doorbell, and the locks. It also includes voice control for most of the systems.

That’s an impressive list, but what really drew our attention to this project is that it used to be based on domoticz, but that community has waned over the years and [superczar] had kept his system patched together with self-built scripts. An accidental upgrade recently broke the entire setup, so rather than rebuild everything a migration was made to home-assistant, an open-source platform that has a more active community. We’ve seen plenty of projects around here that use it as a platform, for ceiling fans, custom remotes, and doorbells.

Thanks to [pradeepmur] for the tip!

Heater Joins The Internet Of Things With ESP32 Board

July 8, 2020 by Tom Nardi 15 Comments

The wood-burning heater [g3gg0] has at home works perfectly, except for one flaw: the pellet reservoir needs to be manually refilled every few days. Humans being notoriously unreliable creatures, this critical task is sometimes overlooked, which naturally leads to literally chilling results.

With automatic fill systems expensive and difficult to install, [g3gg0] wanted to find some kind of way for the heater to notify its caretakers about any potential fault conditions. Not just the fact that it was out of fuel (though that would naturally be the most common alert), but any other issue which would potentially keep the heater from doing it’s job. In short, the heater was going to get a one-way ticket to the Internet of Things.

As it turns out, this task was not quite as difficult as you might expect. The Windhager heater already had upgrade bays where the user could insert additional modules and sensors, as well as a rudimentary data bus over RS-485. All [g3gg0] had to do was tap into this bus, decode what the packets contained, and use the information to generate alerts over the network. The ESP32 was more than up to the task, it just needed a custom PCB and 3D printed enclosure that would allow it to slot into the heater like an official expansion module.

When an interesting message flashes across the bus, the ESP32 captures it and relays the appropriate message to an MQTT broker. From there, the automation possibilities are nearly endless. In this case, the heater’s status information is being visualized with tools like Grafana, and important alerts are sent out to mobile devices with PushingBox. With a setup like this, the Windhager will never go hungry again.

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