Raspberry Pi Home Automation for the Holidays

When you want to play around with a new technology, do you jump straight to production machinery? Nope. Nothing beats a simplified model as proof of concept. And the only thing better than a good proof of concept is an amusing proof of concept. In that spirit [Eric Tsai], alias [electronichamsters], built the world’s most complicated electronic gingerbread house this Christmas, because a home-automated gingerbread house is still simpler than a home-automated home.

fya59blixaq00y3-largeYeah, there are blinky lights and it’s all controlled by his smartphone. That’s just the basics. The crux of the demo, however, is the Bluetooth-to-MQTT gateway that he built along the way. A Raspberry Pi with a BTLE radio receives local data from BTLE sensors and pushes them off to an MQTT server, where they can in principle be read from anywhere in the world. If you’ve tried to network battery-powered ESP8266 nodes, you know that battery life is the Achilles heel. Swapping over to BTLE for the radio layer makes a lot of sense.

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IoT-ify All Things: LG Has Gone Overboard

If you been following Hackaday lately, you’ve surely noticed an increased number of articles about IoT-ifying stuff. It’s a cool project to take something old (or new) and improve its connectivity, usually via WiFi, making it part of the Internet of Things. Several easy to use modules, in particular the ESP8266, are making a huge contribution to this trend. It’s satisfactory to see our homes with an ESP8266 in every light switch and outlet or to control our old stereo with our iPhone. It gives us a warm fuzzy feeling. And that’s completely fine for one’s personal projects.

But what happens when this becomes mainstream? When literally all our appliances are ‘connected’ in the near future? The implications might be a lot harder to predict than expected. The near future, it seems, starts now.

This year, at CES, LG Electronics (LG) has introduced Smart InstaView™, a refrigerator that’s powered by webOS smart platform and integrated with Amazon’s Alexa Voice Service.

… with webOS, consumers can also explore a host of WiFi-enabled features directly on the refrigerator, creating a streamlined and powerful food management system all housed directly on the front of the fridge door. Amazon’s Alexa Voice Service gives users access to an intelligent personal assistant that, in addition to searching recipes, can play music, place Prime-eligible orders from Amazon.com…

This is ‘just’ a fridge. There are other WiFi-enabled appliances by now, so what?  Apparently, during the LG press conference last Wednesday, the company marketing VP David VanderWaal said that from 2017 on, all of LG’s home appliances will feature “advanced Wi-Fi connectivity”.

Notice the word advanced, we wonder what that means? Will ‘advanced’ mean complicated? Mesh? Secure? Intelligent? Will our toaster finally break the Internet and ruin it for everyone by the end of the year? Will the other big players in the home appliances market jump in the WiFi wagon? We bet the answer is yes.

Here be dragons.

[via Ars Technica]

Light Dimmer Shows How to Steal Power from AC Line

We see a lot of traffic on the tips line with projects that cover old ground but do so in an instructive way, giving us insight into the basics of electronics. Sure, commercial versions of this IR-controlled light dimmer have been available for decades. But seeing how one works might just help you design your Next Big Thing.

Like many electronic controls, the previous version of this hack required a connection to a neutral in addition to the hot. This version of the circuit relies on passing a small current through the light bulb the dimmer controls to avoid that extra connection. This design limits application to resistive loads like incandescent bulbs. But it’s still a cool circuit, and [Muris] goes into great detail explaining how it works.

We think the neatest bit is the power supply that actually shorts itself out to turn on the load. A PIC controls a triac connected across the supply by monitoring power line zero-crossing. The PIC controls dimming by delaying the time the triac fires, which trims the peaks off of the AC waveform. The PIC is powered by a large capacitor while the triac is conducting, preventing it from resetting until the circuit can start stealing power again. Pretty clever stuff, and a nice PCB design to boot.

Given the pace of technological and cultural change, it might be that [Muris]’ dimmer is already largely obsolete since it won’t work with CFLs or LEDs. But we can see other applications for non-switched mode transformerless power supplies. And then again, we reported on [Muris]’s original dimmer back in 2009, so the basic design has staying power.

“Alexa, Order Everyone In San Diego A Doll House”

Every day it seems there is a new Alexa story in the news, as for the moment the Amazon voice assistant is in the ascendant over its rivals from Google, Apple, and Microsoft. Today’s slice of Alexa weirdness comes courtesy of a newsreader in San Diego, who inadvertently triggered Alexa-enabled devices within hearing distance of a television to buy doll houses when he reported on a Dallas child’s accidental purchase.

It’s unclear whether any doll houses were dispatched or whether the Echos and Dots merely started the process and asked their owners for confirmation, but we hope it serves to draw attention to the risks associated with an always-on and always-listening device. We’ve looked at how the technology has seemingly circumvented the normal privacy concerns of our own community, so it’s hardly surprising that this kind of incident catches the greater public completely unprepared. It’s one thing for the denizens of a hackspace to troll the owner of a Dot by adding embarrassing products to their wish list, but against a less-informed user who hasn’t worked out how to lock down the device’s purchasing abilities, it’s not too far-fetched to imagine a criminal attack.

Voice assistants are clearly going to become a ubiquitous feature of our lives, and it is inevitable that there will be more such unfortunate incidents which will serve to educate the public about their privacy before the technology reaches maturity. This particular story is definitely Not A Hack, though as our “Alexa” tag shows the devices have huge potential to bring a new dimension to our work. It’s up to all of us in our community to ensure that the voice assistant owners in our lives are adequately educated about them, and maybe resist the urge to say “Alexa, add all the Hackaday merchandise to my wish list!”.

Air Conditioner Speaks Serial, Just Like Everything Else

Like so many other home appliances, it’s likely that even your air conditioner has a serial interface buried inside it. If you’re wondering why, it’s because virtually every microcontroller on the planet has a UART built in, and it’s highly useful for debugging during the development process, so it makes sense to use it. Thus, it was only a matter of time before we saw a hacked airconditioner controlled by a Raspberry Pi.

[Hadley] was growing frustrated with the IR remote for his Mitsubishi air conditioner; it can issue commands, but it’s a one way interface – there’s no feedback on current status or whether commands are received, other then the occasional beep or two. Deciding there had to be a better way, [Hadley] grabbed a Saleae Logic Analyser and started probing around, determining that the unit spoke 5 V TTL at 2400 bps with even parity. The next step was to start talking back.

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Modified Baby Monitor Interrupts Your Groove in Case of Emergency

You try to be good, but the temptation to drown out the noise of parenthood with some great tunes is just too much to resist. The music washes over you, bringing you back to simpler times. But alas, once you plug in the kids started running amok, and now the house is on fire and there’s the cleaning up to do and all that paperwork. Maybe you should have tried modifying a baby monitor to interrupt your music in case of emergency?

Starting with an off-the-shelf baby monitor, [Ben Heck] takes us through the design goals and does a quick teardown of the circuit. A simple audio switching circuit is breadboarded using an ADG436 dual SPDT chip to allow either the baby monitor audio or music fed from your favorite source through to the output. [Ben] wisely chose the path of least resistance to detecting baby noise by using the volume indicating LEDs on the monitor. A 555 one-shot trips for a few seconds when there’s enough noise, which switches the music off and lets you listen in on [Junior]. The nice touch is that all the added components fit nicely in the roomy case and are powered off the monitor’s supply.

Maybe you’d prefer listening to the nippers less than watching them? In that case, this impromptu eye-in-the-sky baby camera might be a better choice.

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Humidity Sensor Shootout

If you want to measure humidity (and temperature, and maybe even barometric pressure) in a device that you’re building, have a look at this comprehensive test of seven different options. We’re going to summarize the results here, but you’ll really want to read up on the testing methodology — it’s great science hacking. Did you know about using saturated salt solutions to produce constant humidity levels for calibration? We didn’t.

The eBay hacker favorite, the so-called DHT22 module, doesn’t fare all that well, with one of six that [Robert] tested being basically horrible, and three of them breaking within two years of use. The one that works well, however, is pretty good. Feeling lucky?

The Bosch BME280 looks great. It costs a bit more as a bare part, and a few times more than that when it is mounted on a friendly module, but it seems to be very reliable. And you get a barometer thrown in for the extra work. Indeed, it performed so well that Hackaday contributor [Nava Whiteford] put the part under a scanning electron microscope to figure out what’s going on.

The other sensors were fine, with the HTU21D and SHT71 being standouts for their ultra-fast response. For the full details, go click on that link at the top. Having just installed a sextet of DHT22s in our house last year, we’re left with that sinking feeling that we may have gotten what we paid for, which wasn’t much. At least they’re all still running.

Thanks to [Dodutils] and [mac012345] via comments in another thread.