Homebrew HVAC systems are one of those projects that take such a big investment of time, effort and money that you’ve got to be a really dedicated (ideally home-owning) hacker with a wide variety of multidisciplinary skills to pull off an implementation that can work in reality. One such HVAC hacker is [Vadim Tkachenko] with his multi-zone Home Climate Control (HCC) project that we covered first back in 2007. We now have rare opportunity to look at the improvements fifteen years of part-time development can produce, when a project is used all day, all year round in their own home. At the start, things were simple, just opening and closing ventilators with none of those modern MQTT-driven cloud computing stuff. Continue reading “Is This The Oldest Open Source HVAC Project In Existence?”→
In certain parts of the world, cooking meat in a regionally-specific way is a critical part of the local culture. From barbeque in the American south to boerewors and braaivleis in South Africa to Montréal smoked meat in French Canada, almost every location has its cookout specialty. So much so that various manufacturers of the tools used for these foods include all kinds of gadgets to monitor the sometimes days-long process of cooking various cuts of meat. [megamarco833]’s smoker, though, includes some tools of his own design.
The smoker is made by a company called Pitboss and includes a rotary switch and control board for maintaining a precise temperature in the smoker. The switch works by changing the voltage value sent to a small microcontroller. By interfacing an ESP32 to this switch, [megamarco833] can remotely change the smoke level and temperature of the smoker. On the software side, it uses a combination of Node-RED and Domoticz to handle the automation and control.
For a cookout that can last hours (if not days) a remotely accessible smoker like this is an invaluable tool if you want to do something other than manually monitor the temperature of your meat for that much time. And, if your barbeque grill or smoker of choice doesn’t already have an embedded control board of some type, we’ve seen analog cooking tools adapted to much the same purpose as this one.
Thanks to [Peter] who sent in the tip and also helped [megamarco833] with the reverse-engineering of the control board!
Have you ever found that, despite having a central heating and air conditioning system, that not all the rooms in your home end up being the temperature you want them to be? Maybe the dining room gets too hot when the heater is running, or the bedroom never seems to cool off enough in the summer months. If that sounds like your house, then these motorized “smart vents” from [Tony Brobston] might be exactly what you need.
The idea here is pretty simple: an ESP8266 and a servo is built into the 3D printed vent register, which allows it to control the position of its louvers. When connected to your home automation system via MQTT, the vents allow you to control the airflow to each room individually based on whatever parameters you wish. Most likely, you’ll want to pair these vents with an array of thermometers distributed throughout the house.
While [Tony] says the design still needs some testing, he’s released smart vents in a range of sizes from 2×10 to 6×12 inches. He’s also provided excellent documentation on how to print, assemble, and program the devices. It’s clear that a lot of care and thought went into every element of this project, and we’re excited to see how it can be developed further by the new ideas and contributors that will inevitably pop up now that it’s gone public.
Amidst the discussions about grid-level energy storage solutions, it is often easy to forget that energy storage can be done on the level of a single house or building as well. The advantages here are that no grid management is needed, with the storage (electrical, thermal, etc.) absorbing the energy as it becomes available, and discharging it when requested. This simplifies the scale of the problem and thus the associated costs significantly.
Perhaps the most common examples of such systems are solar thermal collectors with an associated hot water storage tank, and of course batteries. More recently, the idea of using a battery electric vehicle (BEV, ‘electric car’) as part of a home storage solution is also gaining traction, especially for emergencies where the grid connection has failed due to a storm or similar emergencies. But all-in-all, we don’t see many options for home-level energy storage.
Outwardly, this sleek CO2 monitor designed by [Daniel Gernert] might look like something cooked up in Amazon’s consumer electronics division. But open up that 3D printed case, and you’ll find a surprisingly low parts count that’s been cleverly packed in so as to make the most of the enclosure’s meager internal dimensions.
No wasted space here.
There are, if you can believe it, just three principle components to this device: a Seeed Studio Seeeduino XIAO microcontroller, a Infineon S2GO PAS CO2 sensor board, and a ring of WS2812B LEDs. You could even delete the ring altogether and replace it with a single addressable LED to accomplish the same goal, but we’d say the full ring is money-well-spent if you’re going to spin up your own copy.
Functionality is very straightforward — the LED ring will indicate the detected CO2 concentration by lighting up green and working its way through yellow and onto red. The sensor has no wireless capability, but if you plug it into your computer, you can get a local readout of current conditions.
We love environmental monitoring solutions here almost as much as we love intricately designed 3D printed enclosures. If you’d like to see another project where those two concepts aligned, check out this printable ESP8266 sensor enclosure.
[Flamingo-tech]’s Xiaomi air purifier has a neat safety feature: it will refuse to run if a filter needs replacement. Of course, by “neat” we mean “annoying”. Especially when the purifier sure seems to judge a filter to be useless much earlier than it should. Is your environment relatively clean, and the filter still has legs? Are you using a secondary pre-filter to extend the actual filter’s life? Tough! Time’s up. Not only is this inefficient, but it’s wasteful.
Every Xiaomi filter contains an NTAG213 NFC tag with a unique ID and uses a unique password for communications, but how this password was generated (and therefore how to generate new ones) was not known. This meant that compatible tags recognized by the purifier could not be created. Until now, that is. [Flamingo-tech] has shared the discovery of how Xiaomi generates the password for communication between filter and purifier.
A small NFC sticker is now all it takes to have the purifier recognize a filter as new.
[Flamingo-tech] has long been a proponent of fooling Xiaomi purifiers into acting differently. In the past, this meant installing a modchip to hijack the DRM process. That’s a classic method of getting around nonsense DRM on things like label printers and dishwashers, but in this case, reverse-engineering efforts paid off.
It’s now possible to create simple NFC stickers that play by all the right rules. Is a filter’s time up according to the NFC sticker, but it’s clearly still good? Just peel that NFC sticker off and slap on a new one, and as far as the purifier is concerned, it’s a new filter!
If you’re interested in the reverse-engineering journey, there’s a GitHub repository with all the data. And for those interested in purchasing compatible NFC stickers, [Flamingo-tech] has some available for sale.
Anyone who’s ever slept through a morning’s alarm can tell you that sounds, even loud piercing ones, don’t always wake a person out of a deep sleep. Similarly, hearing a baby cry on the other side of the monitor might not always wake a parent up in the middle of the night. So what’s the solution? This haptic baby monitor created by [Guy Dupont] certainly looks like it has some promise.
[Guy] picked up a fairly standard baby monitor from VTech and popped it open to see how he could tie a vibration motor into the original circuitry. He originally thought he’d have to do some signal processing magic to figure out the amplitude of the audio, but then he realized that the five LEDs on the front of the unit that light up to indicate the audio level were already doing the hard work for him.
Detecting audio level by reading the status of the LEDs.
So he wired each of the LEDs up to the pins of a Seeed Studio XIAO nRF52840 microcontroller, and wrote some code that would poll their status a few hundred times per second. Dividing the total number of LEDs by the count of how many are currently illuminated gives him a nice average that he can use to set the intensity of the vibration motor that he’s built into a stretchy armband.
For extra points, [Guy] is also using the Bluetooth capability of the XIAO to provide a rudimentary configuration service — just connect up to the MCU with a Bluetooth serial application on your computer or phone, and fire off a value between 0 and 10 to augment the motor’s intensity. There’s also a BLE characteristic which can be read from a client device to determine the currently detected audio amplitude, which could be used to chart how well the baby is sleeping over time. Alternately, as demonstrated at the end of the video, you could use it to play Flappy Bird.
It’s an elegant modification that could potentially hold promise for parent’s who need a bit of extra help keeping tabs on their miniature humans. This isn’t the first time we’ve seen hackers try to improve upon the classic baby monitor, but this is arguably the most approachable attempt we’ve seen to date.
