home automation

290 Articles

Cheap Sensor Changes Personality

November 10, 2024 by 27 Comments

If you want to add humidity and temperature sensors to your home automation sensor, you can — like [Maker’s Fun Duck] did — buy some generic ones for about a buck. For a dollar, you get a little square LCD with sensors and a button. You even get the battery. Can you reprogram the firmware to bend it to your will? As [Duck] shows in the video below, you can.

The device advertises some custom BLE services, but [Duck] didn’t want to use the vendor’s phone app, so he cracked the case open. Inside was a microcontroller with Bluetooth, an LCD driver, a sensor IC, and very little else.

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Adding Human Detection To Home Automation

August 29, 2024 by 39 Comments

Radar made a huge impact when it was first invented, allowing objects to be detected using radio waves which would normally be difficult or impossible to observe through other means. Radio waves of all frequencies can be used for radar as well, whether that’s detecting ships beyond the horizon, tracking aircraft near an airport, penetrating the ground, or imaging objects with a high resolution. At the millimeter wavelength it’s fairly easy to detect humans with the right hardware, and using some inexpensive radar modules [Tech Dregs] shows us how to add this capability a home automation system.

Since these modules aren’t trying to image humans with fine detail or detect them at long range, the hardware can be fairly inexpensive. [Tech Dregs] is using the LD2410B modules which have not only an on-board microcontroller but also have the radio antennas used for radar built right onto the PCB. They have a simple binary output which can communicate whether or not a human is detected, but there’s also UART for communicating more details about what the module senses in the room. [Tech Dregs] is using this mode to connect the modules to Home Assistant, where they will be used to help automate his home’s lighting.

The only significant problem he had setting these modules up was getting them built into an enclosure. The short wavelengths used in this type of radar module don’t penetrate solid objects very well at all, so after trying to hide one behind an e-ink screen he eventually settled on hollowing out a space in a bezel with very thin plastic between the module and the room. If you need more out of your radar modules than object detection, though, you can always try building a pulse compression radar which can provide much more accurate ranging of objects.

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Roll Your Own Presence Sensor

August 16, 2024 by 7 Comments

[Mellow_Labs] wanted an Everything Presence Lite but found it was always out of stock. Therefore, he decided to create his own. The kit uses a millimeter wave sensor as a super-sensitive motion tracker for up to three people. It can even read your heart rate remotely. You can see a video of the project below.

There are a few differences from the original kit. Both use the C4001 24 GHz human presence detection sensor. However, the homebrew version also includes a BME680 environmental sensor.

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Read Utility Meters Via SDR To Fill Out Smart Home Stats

July 30, 2024 by 21 Comments

[Jeff Sandberg] has put a fair bit of effort into adding solar and battery storage with associated smarts to his home, but his energy usage statistics were incomplete. His solution was to read data from the utility meter using RTL-SDR to fill in the blanks. The results are good so far, and there’s no reason similar readings for gas and water can’t also be done.

[Jeff] uses the open source home automation software Home Assistant which integrates nicely with his solar and battery backup system, but due to the way his house is wired, it’s only aware of about half of the energy usage in the house. For example, [Jeff]’s heavy appliances get their power directly from the power company and are not part of the solar and battery systems. This means that Home Assistant’s energy statistics are incomplete.

Fortunately, in the USA most smart meters broadcast their data in a manner that an economical software-defined radio like RTL-SDR can access. That provided [Jeff] with the data he needed to get a much more complete picture of his energy usage.

While getting data from utility meters is conceptually straightforward, actually implementing things in a way that integrated with his system took a bit more work. If you’re finding yourself in the same boat, be sure to look at [Jeff]’s documentation to get some ideas.

Automatic Garbage Can Keeps Cooking Cleaner

July 23, 2024 by 30 Comments

Over the last decade or so, we’ve been inundated with appliances with wireless or “smart” technology that is often of dubious utility. No one really needs a tablet in their refrigerator or Wi-Fi on their coffee maker. A less glamorous kitchen appliance that actually might benefit from some automation and connectivity is the garbage can, or “bin” for those speaking the Queen’s English, and [Mellow_Labs] is here to show off just how to get that done with this automatic garbage can lid.

As he explains, the real impetus behind this build is to not have to touch a dirty lid while cooking to avoid having to take time to wash one’s hands again afterwards. There are a few other design criteria as well; it has to be roommate-approved so nothing permanently attached to the lid, overly complicated, or with an unnecessary amount of wires or other fixtures. A servo with an extension sits on the lid itself, and when activated forces the lid open. A distance sensor provides basic gesture recognition and a microcontroller with wireless connectivity controls both and provides home automation integration as well. With a 3D printed case that includes a quick disconnect function for easy cleaning of the lid, the build was ready to be put into service.

The first iteration used an infrared distance sensor, but placing it by an open window caused it to continuously open and close since sunlight has the same wavelengths of light the sensor is tuned for. A quick swap with an ultrasonic sensor solved the problem, and the garbage can is working flawlessly in the kitchen now. Another appliance that is generally not targeted by off-the-shelf automation solutions is the range fume hood, but another build tackled that problem a while back.

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Home Automation Panel Looks Industrial

July 12, 2024 by 14 Comments

Modern tech is great, but we have to admit that we sometimes miss when electronic things looked complicated. A modern computer looks dull compared to, say, an IBM 360. Control rooms now look no different than a stock trading room, instead of being full of indicators, knobs, and buzzers. [BorisDigital] must have some of those same feelings. He built a very cool control panel for his Home Assistant setup. He based it somewhat on a jet cockpit and a little on a nuclear plant control room, and the result, as you can see in the video below, is great.

This is less of a how-to video and more of an inspirational one. After all, you won’t have the same setup, but there are many details about how it was constructed with a Raspberry Pi, 3D printing, and control of the Home Assistant via web services.

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Home Assistant Display Uses E-Ink

May 20, 2024 by 2 Comments

[Markus] grabbed an ESP32 and created a good-looking e-ink dashboard that can act as a status display for Home Automation. However, the hardware is generic enough that it could work as a weather station or even a task scheduler.

The project makes good use of modules, so there isn’t much to build. A Waveshare 2.9-inch e-ink panel and an ESP32, along with a power supply, are all you need. The real work is in the software. Of course, you also need a box to put it in, but with 3D printing, that’s hardly a problem.

Well, it isn’t a problem unless — like [Markus] — you don’t have a 3D printer. Instead, he built a wooden case that also holds notepaper.

The software uses ESPHome to interface with Home Assistant. There is a fair amount of configuration, but nothing too difficult. Of course, you can customize the display to your heart’s content. Overall, this is a great example of how a few modular components and some open-source software can combine to make a very simple yet useful project.

There are many ways to use an ESP32 in your home automation setup. Maybe you can salvage the e-ink displays. Just try not to get carried away.