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.
What do you think of when you hear the word pond? If you’re like most people, it conjures up images of a simple water-filled hole in the ground, maybe with a few fish added in for good measure. But not [Anders Johansson] — his pond is a technical marvel, utilizing more unique pieces of hardware and software than many of the more traditional projects that have graced these projects over the years.
In fact, this is one of those projects that is so grand in scope that any summary we publish here simply can’t do it justice. The aptly-named Poseidon project is built up of several modular components, ranging from an automated fish feeder to an array of sensors to monitor the condition of the water itself. How many other ponds can publish their current water level, pH, and oxygen saturation over MQTT?
The ESP8266 fish feeder is just one element of Poseidon
[Anders] has provided schematics, 3D models, and source code for all the various systems built into the pond, but the documentation is where this project really shines. Each module has it’s own detailed write-up, which should provide you with more than enough guidance should you want to recreate or remix what he’s put together. Even if you use only one or two of the modules he’s put together, you’ll still be ahead of the game compared to the chumps who have to maintain their pond the old fashioned way.
In the past we’ve seen projects that tackled some of the individual elements [Anders] has developed, such as 3D printed fish feeders, but after searching through the archives we can’t find anything that’s even half as ambitious as Poseidon. At least, not for ponds. It reminds us more of a highly advanced aquaponics setup, and we wonder if that might not be a possible spin-off of the core project in the future.
With summer in full swing in the Northern Hemisphere, millions of people are out on vacation leaving millions of homes empty. Thanks to modern technology it’s easier than ever to keep an eye on those empty homes: internet-connected cameras report suspicious activity, and smart-home devices like curtains and light bulbs can be operated from your holiday home. If you’ve got an aquarium and want to keep your fish well-fed during your vacation, then [FoxIS]’s internet-connected automated fish feeder might come in handy too.
The heart of the system is a 3D-printed mechanism that holds a bottle of fish food in a funnel and dispenses a set amount through a servo-operated shutter. The servo is driven by an ESP32 sitting inside an M5StickC IoT development kit. [FoxIS] wanted to use TinyGo for this project, which unfortunately meant that he couldn’t use the ESP32’s built-in WiFi system due to software limitations. He therefore connected the M5StickC to a Raspberry Pi, which he can log into from anywhere in the world to operate the feeding mechanism or to watch his aquatic pets through a USB camera.
Apart from automating the feeding process, the FishFeeder system also keeps track of the aquarium’s temperature through an IR thermometer and shows reminders for other maintenance tasks, such as changing the water or cleaning the filter. A minor inconvenience is the requirement to have that Raspberry Pi present for internet connectivity, but perhaps a future version of TinyGo will support WiFi on the ESP32 and make the FishFeeder a fully self-contained system.
For this tutorial, he took a regular book shelf and mounted it onto a wooden door, with the door itself functioning as the shelf’s back panel, and using the door hinges as primary moving mechanism. Knowing how heavy it would become once it’s filled with books, he added some caster wheels hidden in the bottom as support. As for the (un)locking mechanism, [Alastair] did consider a mechanical lock attached on the door’s back side, pulled by a wire attached to a book. But with safety as one of his main concerns, he wanted to keep the risk of anyone getting locked in without an emergency exit at a minimum. A fail-safe magnetic lock hooked up to an Arduino, along with a kill switch served as solution instead.
