Simple MP3 Player Hides Home Automation Brilliance

August 17, 2020 by Bryan Cockfield 7 Comments

Like bubble wrap or the corkscrew, plenty of everyday objects have lost almost all ties to their original purpose. It could be that the original product had no market but was able to find one in an unexpected place, or simply that the original use case disappeared. We think that this MP3 player for children might arrive at a similar fate as a home automation controller thanks to a recent project by [Sebastian].

The MP3 player is known as a Jooki and works by using small figurines (and a few buttons) to control the device. Different figurines cause the MP3 player to change playlists, for example, but it turns out that the device is capable of communicating over MQTT. This means that [Sebastian] was able to use the MQTT messages from the Jooki to do all kinds of things beyond its intended use with openHAB, an open-source home automation system, such as dimming the lights and closing the blinds when he puts his son to bed.

This platform has considerable potential for hacking thanks to the lightweight communications system it uses under the hood. The Jooki is a little pricey, but if you happen to have one around, it’s an impressive tool that can go well beyond its original intended use.

Automatic Cat Weighing Machine Knows Which Pet It Is Feeding

August 13, 2020 by Jenny List 28 Comments

Have you ever tried to weigh a cat? For that matter, have you ever tried to get a cat to do anything they don’t want to do? The wilful independence of our feline companions is a large part of what endears them to us, and must have done ever since the ancient Egyptians first had a hybrid wildcat that became domesticated

No wonder it’s so hard to care for multiple cats with different dietary needs. But the mere act of weighing the cats just might be the key to automating their diets while giving them the choice of when they want to eat. It’s a task that [Psy0rz] has cracked with the Meowton, a weighing machine/feeder combo designed to regulate the diets of his various moggies.

Cat scale uses a load sensor under each corner of the platform

The multi-faceted system involving a scale to weight the cat, a food hopper with dispenser, and a scale for the food bowl. The cat has to stand on the scale to eat, and the dispenser doles out some food when it detects this. It identifies each cat by weight, and controls the quantity dispensed accordingly to spread that cat’s allotted diet over the course of the day.

Behind it all is an ESP32, which delivers the stats to a web interface and makes them available for import to a database. He’s identified a flaw in the system, that two cats of the same weight could cause misidentification. To that end he has an RFID reader under way, but it’s still a work in progress. There is even a live stream of the unit in action.

We’re suckers for cats here, and while the various Hackaday Cats provide plenty of companionship and entertainment we’re always up for more. Over the years we’ve featured plenty of cat feeders, but only one cat elevator.

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.

Continue reading “Wood-Fired Hot Tub For The End Of The World” →

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.

Continue reading “You’ve Got Rat!” →

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.

Continue reading “Laser Cutting Your Way To An RGB LED Table” →

A Portable Home Air Quality Meter With The ESP32

July 20, 2020 by Lewin Day 20 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.

Continue reading “Home Monitoring, Without All The Sensors” →