Teardown: Impassa SCW9057G-433 Alarm System

September 9, 2021 by Tom Nardi 15 Comments

This series of monthly teardowns was started in early 2018 as an experiment, and since you fine folks keep reading them, I keep making them. But in truth, finding a new and interesting gadget every month can sometimes be a chore. Which is why I’m always so thankful when a reader actually sends something in that they’d like to see taken apart, as it absolves me from having to make the decision myself. Of course it also means I can’t be blamed if you don’t like it, so keep that in mind as well.

Coming our way from the tropical paradise of Eastern Pennsylvania, this month’s subject is an ADT branded Impassa SCW9057G-433 alarm system that was apparently pulled off the wall when our kind patron was moving house. As you might have guessed from the model number, this unit uses 433 MHz to communicate with various sensors and devices throughout the home, and also includes a 3G cellular connection that allows it to contact the alarm monitoring service even if the phone line has been cut.

Diagram of Impassa home security setup — The alarm can connect to a wide array of 433 MHz devices.

From how many of these are on eBay, and the research I’ve done on some home alarm system forums, it appears that you can actually pick one of these up on the second-hand market and spin your own whole-house alarm system without going through a monitoring company like ADT. The extensive documentation from Impassa covers how to wire and configure the device, and as long as the system isn’t locked when you get it, it seems like wiping the configuration and starting from scratch isn’t a problem.

If it’s possible to put together your own homebrew alarm system with one of these units at the core, then it seems the least we can do is take it apart and see what kind of potentially modifiable goodies are waiting under that shiny plastic exterior.

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An electronics workbench with tools and drawers

IKEA Wardrobe Holds Entire Hardware Workspace

September 7, 2021 by Robin Kearey 18 Comments

If you’re like us, you probably don’t finish a typical hardware project in one sitting. This doesn’t have to be a problem if you’re fortunate enough to have a dedicated workbench for your hacking activities; you simply leave your current project there, ready to continue when you have time again. But this is not always a workable option if you, or a housemate, needs to use the same desk for other tasks as well.

[!BATTA!] over at IKEAhackers ran into this problem, and solved it by building a complete electronics workstation inside a wardrobe. The base of this project is a storage unit called PAX, which is designed to store clothes and shoes but which also works just fine with project boxes. [!BATTA!] installed a variety of shelves and drawers to organize their collection of boxes and tools.

Not content with simple storage, [!BATTA!] decided to add a workbench, using a sturdy sliding tray that carries a working surface and a reinforced back panel to hold parts bins. Metal braces were added to prevent wobbliness, and the whole structure was bolted to a wall to prevent it from tipping over. When the workbench is not in use, the tray simply slides inside so the doors can be closed for a nice, clean look.

We really like the many clever storage solutions spread around the work area, such as a magnetic rail to hold hand tools and a “honeycomb” of PVC tubes for storing cables. Compact LED strips provide suitable lighting while a power strip with both mains and USB sockets brings juice to the tools and projects.

Modifying pieces of IKEA furniture is nothing new; we’ve seen them turned into arcade cabinets and MP3 players. We’ve also covered several well-organized workspaces, but none as compact as this one. Thanks to [IrregularShed] for the tip.

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?”

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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.

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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.

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