Home Assistant Get Fingerprint Scanning

Biometrics — like using your fingerprint as a password — is certainly convenient and are pretty commonplace on phones and laptops these days. While their overall security could be a problem, they certainly fit the bill to keep casual intruders out of your system. [Lewis Barclay] had some sensors gathering dust and decided to interface them to his Home Assistant setup using an ESP chip and MQTT.

You can see the device working in the video below. The code is on GitHub, and the only thing we worried about was the overall security. Of course, the security of fingerprint scanners is debatable since you hear stories about people lifting fingerprints with tape and glue, but even beyond that, if you were on the network, it would seem like you could sniff and fake fingerprint messages via MQTT. Depending on your security goals, that might not be a big deal and, of course, that assumes someone could compromise your network to start with.

Continue reading “Home Assistant Get Fingerprint Scanning”

An ESP32 Home Automation Swiss Army Knife

Thanks to the ESP8266 and the ESP32, we’ve seen an explosion in DIY home automation projects recently. When it only takes $3 and a few lines of code to bring your gadgets onto the network, that’s hardly a surprise. But hacking bare ESP modules onto devices will only get you so far. Eventually you’ll probably want to put together a slightly more mature home automation system, and that’s where things can get a little tricky.

Which is why [Alfredo] created the Maisken Homelay. This device is a one-stop-shop for your home automation needs that leverages the power of the ESP32. With the microcontroller slotted into this compact PCB, you’ll be able to trigger four relays for your high current or AC loads, and still have 8 GPIOs and the I2C bus for expansion. All while retaining compatibility with existing open source projects like Home Assistant and ESPHome.

What really sets this project apart is the attention to detail. [Alfredo] has included a HLK-PM01 power supply on the board which takes mains voltage and brings it down to 5 VDC for the ESP32, so won’t need a separate power cable. He’s also taken the time to add isolation slots to separate the potential high-voltage connected to the relays from the rest of the board, added current and thermal fuses for protection, and peppered the board with screw terminals so you can easily connect everything up.

Sure you could get a simple relay board shipped to your door for a few bucks from the usual suspects. But it’s not going to offer the kind of quality of life and safety features that the Maisken Homelay has. There’s even a 3D printed enclosure available to help tidy things up.

With some of the blatantly anti-consumer decisions big-name home automation companies have been making recently, there’s more reason than ever to roll your own smart home using open source hardware and software. It still takes more effort than buying a bunch of modules from the Big Box retailer, but projects like this one are certainly starting to blur the line between consumer and DIY.

Reverse Engineering A Ceiling Fan Remote

In the quest to automate everything in your home, you no doubt have things that aren’t made with home automation in mind. Perhaps your window AC unit, or the dimmer in your dining room. [Seb] has several ceiling fans that are controlled by remotes and wanted to connect them to his home automation system. In doing so, [Seb] gives a good overview of how to tackle this problem and how to design a PCB so he doesn’t have a breadboard lying around connected to the guts of his remote control.

There are several things [Seb] needs to figure out in order to connect his fans to Home Assistant, the home automation system he uses: He needs to determine if the circuit in the remote can be powered by 5 or 3.3 V, he needs to connect the circuit to an ESP32 board, and he needs to figure out if he can create a custom PCB that combines the circuit and the ESP32 into one. The video goes through each of these steps and shows the development of each along the way.

There’s a lot of info in the video, so it might need to be slowed down a bit to see all the details. There are some other reverse engineering of home automation gear on the site, here, or, you might want to build your own remote to control your automated devices.

Continue reading “Reverse Engineering A Ceiling Fan Remote”

Handheld MQTT Remote For Home Automation

If you’re working on a home automation project, you’re probably knee-deep into MQTT by now. If not, you should be. The lightweight messaging protocol is an ideal choice for getting your “Things” on the Internet, and controlling them all can be done easily through a simple web interface or an application on your mobile device. Or if you’re [serverframework], you make yourself a handsome little all-in-one MQTT remote.

The hardware here is pretty simple; inside there’s just a NodeMCU ESP8266 development board, some buttons, an RGB LED to give feedback, and a 3.7v 1200mAh LiPo battery with associated charging module. Everything is held inside a nice little wooden box that looks like it would fit right in with the living room decor. We’d like to see some kind of a cover over the exposed perfboard the circuit is assembled on, but that’s arguably a personal preference kind of thing.

Most of the magic in this project is actually happening on the software side. Not only does the provided source code handle all the MQTT communications with Home Assistant, but it provides a clever user interface that allows [serverframework] to perform 25 functions with just five buttons. No, you aren’t seeing things. There are actually six buttons on the device, but one of them is a dedicated “power” button that wakes the remote out of deep sleep.

If you’d like to learn more about getting this protocol working for you, our resident MQTT guru [Elliot Williams] has plenty of thoughts on the subject. From his talk at the 2017 Hackaday Supercon to his home automation tutorial series, there’s plenty of information to get you started.

Continue reading “Handheld MQTT Remote For Home Automation”

Does Your Home Assistant Know When You Are Sleeping?

It always gives us a sense of wonder when we realize that what would be a simple task for a human child is a big deal for a computer. For example, if you asked someone if you or someone else was in bed, that’s a pretty simple thing to check. For you, that is. For a computer, it requires some sort of sensor. [Lewis] used load cells to tell if someone is in a particular bed or not. He uses Home Assistant and has a great post about how he created and interfaced the sensors. Of course, the sensors really only tell you if something heavy is in the bed. It doesn’t know who it is or even that it isn’t an overstuffed suitcase.

Load cells aren’t exactly high tech. There are several different types that use hydraulic pressure or pneumatics to measure force. However, the most common that we encounter use strain gauges. A strain gauge is a resistor that changes value when it deformed and a load cell usually has several strain gauges wired in a bridge configuration so that small forces create larger output changes.

Continue reading “Does Your Home Assistant Know When You Are Sleeping?”

Sniffed Transformer Puts Wired Doorbell Online

There’s certainly no shortage of “smart” gadgets out there that will provide you with a notification, or even a live audiovisual stream, whenever somebody is at your door. But as we’ve seen countless times before, not everyone is thrilled with the terms that most of these products operate under. Getting a notification on your phone when the pizza guy shows up shouldn’t require an email address, credit card number, or DNA sample.

For [Nick Touran], half the work was already done. There was already a traditional wired doorbell in his home, he just had to come up with a minimally invasive way to link it with Home Assistant. He reasoned that he could tap into the low-voltage side of the doorbell transformer and watch for the telltale fluctuations that would indicate the bell was doing its thing. The ESP8266 has an ADC to measure voltage and WiFi to connect to Home Assistant, so it seemed like the perfect bridge between old and new.

Transformer voltage before and after

Of course, as with any worthwhile project, it ended up being a bit more complicated. Wired doorbells generally operate on 16-24 VAC, and [Nick] knew if he tried to put his Wemos D1 across the line he’d release the critical Magic Smoke. What he needed was a voltage divider circuit that would take low-voltage AC and drop it to an even lower DC voltage that the microcontroller could cope with.

The simple circuit [Nick] comes up with cuts the voltage way down and removes the negative component completely. So what was originally 18.75 VAC turned into a series of 60 Hz blips at 2.4 VDC; perfect for feeding into a microcontroller ADC. With a baseline to work from, he could then write some code that would watch for variations in this signal to determine when the bell was ringing.

Or at least, that was the idea. While the setup worked well enough on the bench, its performance in the real-world left something to be desired. If his house guest had a heavy hand, it worked great. But a quick tap of the doorbell button would tend to go undetected. After investigating the issue, [Nick] found that he needed to use some software trickery to ensure the ESP8266 was able to keep up with the speedy signal. Once he was able to reliably detect short and long button presses, the rest was just a simple matter of sending an MQTT message to his automation system.

Compared to the hoops we’ve seen other hackers have to jump through to smarten up their doorbells, we think [Nick] got off fairly easy. This project is also an excellent example of how learning about circuit design and passive components can still come in handy in the Arduino Era.

Continue reading “Sniffed Transformer Puts Wired Doorbell Online”

New Part Day: Put An Alexa In Everything

The last great hope for electronics manufactures is smart home assistants. The Alexas and Siris and OK Googles are taking over homes across the country. At its best, it’s HAL 9000, only slightly less homicidal. It will entertain your children, and you can order cat litter just by saying you want cat litter. This is the future, whether we like it or not.

In an attempt to capture the market, Amazon has released the Alexa Connect Kit. This is an Amazon-Echo-On-a-Chip — a piece of hardware that adds Alexa to microwaves, blenders, and whatever other bit of home electronics you can imagine.

The Alexa Connect Kit is the hardware behind Amazon’s efforts to allow developers easy integration with Alexa. The options for adding Alexa to a product up until now have been using Zigbee to connect an Echo Show or Echo Plus, or simply giving a device the ability to connect to an Echo through Bluetooth. The Alexa Connect Kit, however, is a pure hardware solution that puts Alexa in anything.

Unfortunately you can’t get one yet. Right now, the Alexa Connect Kit is just a preview, and if you want to get your hands on one — or get any specs on this bit of hardware — you’ll need to apply to the developer program. We’ve signed up and will share and juicy details that come our way as part of the program.

According to the Wall Street Journal (try Google referral link if you hit the pay wall), several companies are already working on integrating the Alexa Connect Kit into their existing product lines. Hamilton Beach and Procter & Gamble are both working on something, although the press doesn’t say what kind of device will now be loaded up with a voice assistant. Amazon, however, has a microwave using the technology that the owner can, “command the microwave to do things like defrost a half-pound of chicken, or set it up to automatically reorder a favorite type of popcorn on Amazon”.

Despite the sparse details, this is relatively game-changing when it comes to the world of homebrew electronics. We’ve seen dozens of projects using hacked Raspberry Pis and other microcontrollers to at Alexa to hacked coffee machines, to shoot Nerf darts, and to control a projector. If you can actually get one of these Alexas-on-a-chip, all those projects could be done with one simple piece of hardware.