an image of the mechanism used to move the curtains

Clever Mechanism Easily Automates Pulling The Blinds

August 29, 2021 by Jim Heaney 15 Comments

There are few things that we all can agree we hate, and the shrill of your alarm clock waking you from a wonderful slumber is definitely high on that list. To wake up more naturally, [nutstobutts] created an automated curtain opener.

The curtain opener is very simple; a stepper motor in the control box pulls a string, which is run to an idler on the far side of the curtain rod and through two clips, attached to the back of each curtain. This design makes it so that both curtains will open smoothly at the same time, and will always come closed again directly in the center. This design is especially favorable for students in dorms or those that live in an apartment, as the installation requires no screws in the wall or permanent modification to the curtains.

The curtains can be opened and closed either by pressing a button on the control box or by sending HTTP requests to the ESP32 that controls everything. This allows for integration with many different IoT systems, for instance [nutstobutts] has been having Home Assistant open the curtains every morning at 6:30 a.m. in lieu of an alarm clock, and then closing them automatically at 9:00 a.m. to help save on cooling costs.

Automated curtains are a great first IoT project if you are looking to just get your feet wet, check out a different style we covered a few months back for more inspiration!

[via r/functionalprint]

100% display from filter screen and the responsible mod chip

Clearing The Air About Proprietary Consumables With A Xiaomi Filter DRM Resetter

August 28, 2021 by Brian McEvoy 16 Comments

The “razor and blades model” probably set a lot of young hackers on their current trajectory. If we buy a widget, we want to pick our widget refills instead of going back to the manufacturer for their name-brand option. [Flamingo-Tech] was having none of it when they needed a new filter for their Xiaomi air purifier so they set out to fool it into thinking there was a genuine replacement fresh from the box. Unlike a razor handle, the air purifier can refuse to work if it is not happy, so the best option was to make a “mod-chip.”

The manufacturer’s filters have a Near-Field Communication (NFC) chip and antenna which talk to the base station. The controller receives the filter data via I₂C, but the mod-chip replaces that transmitter and reassures the controller that everything is peachy in filter town. On top of the obvious hack here, [Flamingo-Tech] shows us how to extend filter life with inexpensive wraps, so that’s a twofer. You can create your own mod-chip from the open-source files or grab one from [Flamingo-Tech’s] Tindie store.

We usually hear about mod-chips in relation to games, but we are happy to extend that honor to 3D printers. Have you ever fooled a “razor?”

Continue reading “Clearing The Air About Proprietary Consumables With A Xiaomi Filter DRM Resetter” →

ESP8266 weather widget with touchscreen display

Nothing Should Cloud The Build Of This Wieldy Weather Widget

August 23, 2021 by Kristina Panos 9 Comments

Weather is one of those things that seems to be endlessly interesting to hackers. We may decry the notion that weather can be accurately predicted two days out, much less seven, but if there’s an extended forecast available, by gosh we’re gonna take a gander at it.

So why pick up your phone or open a browser tab every time you want to check the temperature? If you’re so into it, you should build a desktop weather widget. [opengreenenergy] has written a great guide to a tidy build of this classic and oh-so-useful project that covers everything from the soldering to obtaining an API key. Inside is an ESP8266 and a 2.8″ touch screen display that shows localized conditions via Open Weather Map. The main screen shows the time, date, current weather, 7-day forecast, and the moon phase for each day, and subsequent screens go into further detail. It’s informative without being busy.

We love the streamlined look of the snap-fit enclosure. This may be a fairly simple project, but the build as designed is challenging due to the space constraints inside. Check out the video after the break, which features the venerable Stickvise.

What? You’ve never heard of the Stickvise? You must be new around here. Allow me to introduce you two.

Continue reading “Nothing Should Cloud The Build Of This Wieldy Weather Widget” →

Electromagnetic Interference For Fun And Profit

August 22, 2021 by Jenny List 24 Comments

There was an urban legend back in the days of mechanical electricity meters, that there were “lucky” appliances that once plugged in would make the meter go backwards. It probably has its origin in the interaction between a strongly capacitive load and the inductance of the coils in the meter but remains largely apocryphal for the average home user. That’s not to say that a meter can’t be fooled into doing strange things though, as a team at the University of Twente have demonstrated by sending some more modern meters running backwards. How have they performed this miracle? Electromagnetic interference from a dimmer switch.

Reading the paper (PDF link) it becomes apparent that this behavior is the result of the dimmer switch having the ability to move the phase of the current pulse with respect to the voltage cycle. AC dimmers are old hat in 2021, but for those unfamiliar with their operation they work by switching themselves on only for a portion of the mains cycle. The cycle time is varied by the dimming control. Thus the time between the mains zero-crossing point and their turn-on point is equivalent to a phase shift of the current waveform. Since electricity meters depend heavily upon this phase relationship, their performance can be tuned. Perhaps European stores will now brace themselves for a run on dimmer switches.

If you’re curious about these old-style dimmers, take a look at some of their basic functionality.

Thanks [Dorus] for the tip.

Voice-Controlled Smart Home From The Foundation Up

August 16, 2021 by Bryan Cockfield 20 Comments

Smart homes are becoming an increasingly popular way to automate one’s home, whether it’s turning on lights, closing blinds, or even feeding pets. But the commercial offerings often rely on an internet connection to reach servers in order to work, which invites a lot of privacy concerns for a large percentage of us as well as being inconvenient when the internet is down. Essentially the only way to have a privacy-respecting, self-sufficient smart home is to build one on your own from the ground up, which is exactly what [Xasin] has done with this project.

This build is based on ESP32 modules with a Raspberry Pi as a hub, but it’s not as simple as a MQTT implementation. Not only does the self-contained home automation setup not rely on any outside services, but a failure of the central Pi server will not impact the nodes either as they are configured to continue operating independently even without central control. This allows for a robust home automation implementation without a single point of failure, and also includes some other features that are helpful as well including voice control, all while retaining a core design philosophy that makes it relatively easy to build.

Not only is the build technologically impressive for its standalone capabilities and its elimination of privacy concerns, but [Xasin] also did an excellent job with the physical design as well, adding plenty of RGB and a hexagonal enclosure that gives it a unique look wherever its is placed. If you’re renting right now or otherwise unable to interface any automation with your current home, be sure to take a look at some projects that do home automation without making any permanent changes.

Continue reading “Voice-Controlled Smart Home From The Foundation Up” →

ESP8266 Adds WiFi Logging To IKEA’s Air Quality Sensor

July 24, 2021 by Tom Nardi 38 Comments

Introduced back in June, the IKEA VINDRIKTNING is a $12 USD sensor that uses colored LEDs to indicate the relative air quality in your home depending on how many particles it sucks up. Looking to improve on this simplistic interface, [Sören Beye] tacked an ESP8266 to the board so it can broadcast sensor readings out over MQTT.

Just three wires link the ESP8266 to the PCB.

While some of us would have been tempted to gut the VINDRIKTNING and attach its particle sensor directly to the ESP8266, the approach [Sören] has used is actually quite elegant. Rather than replacing IKEA’s electronics, the microcontroller is simply listening in on the UART communications between the sensor and the original controller. This not only preserves the stock functionality of the VINDRIKTNING, but simplifies the code as the ESP doesn’t need to do nearly as much.

All you need to do if you want to perform this modification is solder a couple wires to convenient test pads on the VINDRIKTNING board, then flash the firmware (or write your own version), and you’re good to go. There’s plenty of room inside the case for the ESP8266, though you may want to tape it down so it doesn’t impact air flow.

While not required, [Sören] also recommends making a small modification to the VINDRIKTNING which makes it a bit quieter. Apparently the 5 V fan inside the sensor is occasionally revved up by the original controller, rather than kept at a continuous level that you can mentally tune out. But by attaching the sensor’s fan to the ESP8266’s 3.3 V pin, it will run continuously at a lower speed.

We’ve seen custom firmware for IKEA products before, but this approach, which keeps the device’s functionality intact regardless of what’s been flashed to the secondary microcontroller, is particularly appealing for those of us who can’t seem to keep the gremlins out of our code.

[Thanks to nexgensri for the tip.]

Live Energy Monitor Helps Plan Power-Hungry Appliance Use

July 20, 2021 by Donald Papp 8 Comments

There are a lot of good reasons to have a better understanding of one’s household power use, and that is especially true for those that do their own solar power collection. For example, [Frederick] determined that it would be more efficient to use large appliances (like a dishwasher or washing machine) when there was excess solar power available, but the challenge was in accessing the right data in a convenient way. His Raspberry Pi-based live energy monitor was the solution, because it uses an LED matrix to display live energy data that can be consulted at a glance.

Interestingly, this project isn’t about hacking the power meter. What this project is really about is conveniently accessing that data when and where it is best needed. [Frederick] has a digital power and gas meter with the ability to accept a small wireless dongle. That dongle allows a mobile phone app to monitor power usage, including whether power is being taken from or exported to the grid.

Since [Frederick] didn’t want to have to constantly consult his mobile phone, a Raspberry Pi using a Pimoroni Unicorn HAT HD acts as a glanceable display. His Python script polls the power meter directly over WiFi, then creates a live display of power usage: one LED for every 250 W of power, with the top half of the display being power used, and the bottom half representing power exported to the grid. Now the decision of when to turn on which appliances for maximum efficiency is much easier, not by automating the appliances themselves, but simply by displaying data where it needs to be seen. (This kind of thing, incidentally, is exactly the idea behind the Rethink Displays challenge of the 2021 Hackaday Prize.)

As for those of us without a digital power meter that makes it easy for residents to access power data? It turns out there is no reason a power meter’s wireless service interface can’t be sniffed with RTL-SDR.