ESP32 Adds New Features To 1990s Home Alarm System

November 2, 2020 by Tom Nardi 16 Comments

Given how fast technology is progressing, some consumer gadgets lend themselves to being replaced every few years. Mobile phones are a particularly good example of a device that you probably won’t want to hold onto for more than 4 years or so, with TVs not far behind them. On the other hand, something like a home alarm system can stay in the fight for decades. As long as it still goes off when somebody tries to pop a window, what more do you need?

Well if you’re like [Brett Laniosh], you might want the ability to arm the system and check its current status from your phone. But instead of getting a whole new system, he decided to upgrade his circa 1993 Gardiner Gardtec 800 alarm with an ESP32. As it so happens, the original panel has an expansion connector which he was able to tap into without making any modifications to the alarm itself. If you’ve got a similar panel, you might even be able to use his source code and circuit schematics to perform your own modification.

Optocouplers link the ESP and alarm panel.

Now we know what you’re thinking. Surely there’s a risk involved when trusting an ESP32 connected to the Internet with the ability to disarm your home alarm system. [Brett] has considered this, and made sure that the web server running on the microcontroller can only be accessed from the local network. If he does want to connect from beyond WiFi range, he does so through a VPN. In other words, his code is never directly exposed to the wilds of the Internet and is always hiding behind some kind of encryption.

The WiFi connection allows [Brett] to arm and disarm the alarm system remotely, check if it’s been triggered, and reset it if necessary, all from his smartphone. But he’s also added in a 433 MHz receiver so he can use simple handheld fobs to arm the system if he doesn’t want to go through the phone. Even if you dropped out the Internet connectivity, this alone is a pretty nice upgrade.

For those not afraid to take the more invasive route, you could potentially reverse engineer and reprogram your old alarm panel. Or you could even so the full DIY route and create your own low-cost alarm system using the ESP32 and off-the-shelf modules.

The Ground Beneath Your Feet: SuperAdobe Construction

October 27, 2020 by Bryan Cockfield 25 Comments

Homes in different parts of the world used to look different from each other out of necessity, built to optimize for the challenges and benefits of local climate. When residential climate control systems became commonplace that changed. Where a home in tropical south Florida once required very different building methods (and materials) compared to a home in the cold mountains of New England, essentially identical construction methods are now used for single-family homes in any climate. The result is inefficient and virtually indistinguishable housing from coast to coast, regardless of climate. As regions throughout the world are facing increasingly dire housing shortages, the race is on to find solutions that are economical and available to us right now.

The mission of CalEarth, one of the non-profits that Hackaday has teamed up with for this year’s Hackaday Prize, is to address that housing shortage by building energy-efficient homes out of materials already available in the areas that they will be built. CalEarth specializes in building adobe, or earth, homes that have a large thermal mass and an inexpensive bill of materials. Not only does this save on heating and cooling costs, but transportation costs for materials can be reduced as well. Some downside to this method of construction are increased labor costs and the necessity of geometric precision of the construction method, both of which are tackled in this two-month design challenge.

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How An Engineer Designs A DIY Energy Recovery Ventilator

October 21, 2020 by Dan Maloney 80 Comments

We have no idea whether [Nick Goodey] is a trained engineer or not. But given the detailed design of this DIY energy recovery ventilator for his home HVAC system, we’re going to go out on a limb and say he probably knows what he’s doing.

For those not in the know, an energy recovery ventilator (ERV) is an increasingly common piece of equipment in modern residential and commercial construction. As buildings have become progressively “tighter” to decrease heating and cooling energy losses to the environment, the air inside them has gotten increasingly stale. ERVs solve the problem by bringing fresh, unconditioned air in from the outside while venting stale but conditioned air to the outside. The two streams pass each other in a heat exchanger so that much of the energy put into the conditioned air is transferred to the incoming unconditioned air.

While ERV systems are readily available commercially, [Nick] decided to roll his own after a few experiments with Coroplast and some extensive calculations convinced him it would be a viable idea. One may scoff at the idea of corrugated plastic for the heat exchanger, but the smooth channels through the material make it a great choice. He built up a block of Coroplast squares with the channels in alternate layers oriented orthogonally, letting stale inside air pass very close to fresh outside air to exchange heat without ever mixing directly. The entire system, including fans, an Arduino for control, sensors galore, and the Hubitat home automation hub, is powered by DC, so no electrician was needed. [Nick] has a ton of detail in his build log, including all the tools and calculators he used to design the system.

Given the expense of ERV systems, we’re surprised we haven’t seen more stories about DIY versions. We have talked about HVAC systems a lot, though — after all, HVAC techs are hackers who make housecalls.

Saving Floor Space With A Scratch Built Bike Hoist

October 16, 2020 by Tom Nardi 14 Comments

Vertical storage is often underused in the garage or workshop as it can be tricky to get bulky objects off the floor safely. So we stick a few shelves on the wall, put boxes of screws and components on them, and call it a day. Meanwhile, you end up playing a game of horizontal Tetris with all the big stuff on the ground.

Looking to free up some floor space in his garage, [Chris Chimienti] recently decided to design and build his own hoist to lift his bicycles off the floor. While his design is obviously purpose built for bikes, the core concept could potentially be adapted to lift whatever it is you’ve been kicking across the garage floor as of late; assuming it doesn’t have any strong feelings on suddenly being tipped over on its side, anyway.

A simple modification allows for operation with a drill.

Before he started the actual build, [Chris] knocked together a rough facsimile of his garage in SolidWorks and started experimenting with the layout and mechanism that the hoist would ultimately use. While we’ve all felt the desire to run into a project full-speed, this more methodical approach can definitely save you time and money when working on a complex project. Redesigning a component in CAD to try it a different way will always be faster and easier than having to do it for real.

We’ve become accustomed to seeing projects include sensors, microcontrollers, and 3D printed components as a matter of course, but [Chris] kept this build relatively low-tech. Not that we blame him when heavy overhead loads are involved. Even still, he did have to make a few tweaks in the name of safety: his original ratcheting winch could freewheel under load, so he swapped it out for a worm gear version that he operates with an electric drill.

If you like the idea of having an overhead storage area but don’t necessarily want to look at it, you could always cover it up with a rock climbing wall.

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Gas Powered Blender Packs Real Grunt

October 16, 2020 by Lewin Day 17 Comments

Whether you’re into fruit smoothies or icy blended cocktails, a blender comes in handy when preparing these beverages in the kitchen. But, if a small electric motor can do the job well, a noisy combustion engine can certainly do it louder. This is demonstrated ably by this project from [JT Makes It].

The build is a steel-framed contraption, mounting a small gas engine of the type you’d typically find in a weed trimmer or other garden tool. It’s attached to a shaft allowing it to spin a blender blade at up to 41,000 rpm when unloaded. A stout metal container is mounted on top, along with a plexiglass lid to ensure the contents of the bowl don’t escape when the blender is in action.

It’s a fun build, and one that has no trouble turning a bucket of apples into mush in under 60 seconds. More realistically, [JT] is able to whip up several litres of blended cocktail without major effort, which would be great for parties. Though, we do imagine the burning oil and gas fumes does somewhat spoil the taste sensation. We’ve seen similar hacks before, like this nitro-fuelled pencil sharpener. Video after the break.

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A Smart Speaker That Reminds You It’s Listening

October 15, 2020 by Matthew Carlson 20 Comments

[markw2k9] has an Alexa device that sits in his kitchen and decided it was time to spruce it up with some rather uncanny eyes. With some inspiration from the Adafruit Uncanny Eyes project, which displays similar animated eyes, [markw2k9] designed a 3d printed shell that goes on top of a 2nd generation Amazon Echo. A teensy 3.2 powers two OLED displays and monitors the light ring to know when to turn the lights on and show that your smart speaker is listening. The eyes look around in a shifty sort of manner. Light from the echo’s LED ring is diffused through a piece of plexiglass that was lightly sanded on the outside ring and the eye lenses are 30mm cabochons (a glass lens often used for jewelry).

One hiccup is that the ring on the Echo will glow in a steady pattern when there’s a notification. As this would cause the OLEDs to be on almost continuously and concerned for the lifetime of the OLED panels, the decision was made to detect this condition in the state machine and go into a timeout state. With that issue solved, the whole thing came together nicely. Where this project really shines is the design and execution. The case is sleek PLA and the whole thing looks professional.

We’ve seen a few other projects inspired by the animated eyes project such as this Halloween themed robot that is honestly quite terrifying. The software and STL files for the smart speaker’s eyes are on Github and Thingiverse.

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An Open Source IR Gateway Based On The ESP8266

October 14, 2020 by Tom Nardi 26 Comments

The market is absolutely inundated with smart gadgets, with everything from coffee makers to TVs advertising that they support the latest and greatest in home automation platforms. Don’t worry about how many of those platforms and services will still up up and running in the next few years, the thing will probably stop working before then anyway. No sense worrying about the details in a disposable world.

Of course, not all of us are so quick to dump working hardware in the name of the latest consumer trend. Which is why [Viktor] has developed an open source infrared gateway that can connect your “dumb” devices to the latest flash in the pan backend service with nothing more than a software update. Though even modern smart TVs still include IR remotes, so there’s nothing stopping you from using it with newer gear if you don’t ~~trust~~ like the built-in implementation.

The hardware here is really quite simple, essentially boiling down to a few IR LEDs and an IR receiver hanging off the GPIO ports of an ESP8266. While the receiver isn’t strictly necessary, it does allow [Viktor] to rapidly implement new IR codes. He just points the existing remote at the board, hits a button, and the decoded command gets sent out over MQTT where he can easily snap it up.

[Viktor] has done the hard work of creating the PCB design and testing out different IR LEDs to find the ones with the best performance. But if you wanted to just throw something together in a weekend, you should be able to get his firmware running with little more than a bare ESP and a random IR LED salvaged from an old remote. But don’t be surprised if you get hooked on the concept and end up rolling your own home automation system.