Toy Bulldozer Becomes Epic Terrifying Lawnmower

September 16, 2023 by Lewin Day 14 Comments

Regular lawnmowers are a perfectly fine way to mow your lawn, but they can be a bit boring. They’re also not always the best at tackling thick brush and bushes. [rctestflight] has a solution to both of those problems, in the form of a plant-munching bulldozer.

The concept is simple — it starts with a hefty miniature RC bulldozer. Weighing in at 27 kilograms (60 pounds), the beast has actual functioning hydraulics to control the blade and plow. It struggles somewhat with traction, particularly in muddier conditions, and can’t really dig much, but it nonetheless looks the business.

As cool as it was, [rctestflight] decided to employ it for some real yard work by outfitting it with a mowing rig. The ‘dozer was outfitted with a pair of sawblades, run by twin brushless motors for plenty of grunt. That gave the bulldozer the ability to mow through not just lawn, but even thick blackberry bushes and two-foot high weeds.

It’s not great at steering, but it’s able to destroy thick brush with reckless abandon. Fundamentally, it looks like a very fun way to mow an overgrown yard.

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Grannophone Helps You Stay In Touch

September 10, 2023 by Kristina Panos 20 Comments

Whether it’s distance, pandemics, or both that separate you from your elderly loved ones, what’s the best idea for communicating with them so they don’t suffer from loneliness on top of issues like dementia? We’d say it’s probably something like [Stefan Baur]’s Grannophone.

Back in late 2020, a Twitter user named [Nitek] asked the Internet what could be done in the way of a grandma-friendly video-conferencing solution, provided Grandma has a TV and a broadband internet connection. At first, [Stefan] was like, just get her an old iPad and FaceTime with her. But the question got him thinking. And prototyping.

Grannophones are essentially Linux machines with a video-capable SIP client connected over a VPN for privacy reasons. In simple mode, picking up the handset of one Grannophone will call the other, but more complicated configurations are possible. We particularly like that replacing the handset automatically obscures the camera. That’s a nice touch.

At this point, the Grannophone is a work in progress. The idea is that they be extremely easy to build at the kitchen table, like on the order of disposable Swedish furniture. If you can contribute to the project, please do. Be sure to check out the demonstration video after the break.

On the other hand, if Granny is 1337, you could always video-conference in terminal.

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An automatic laser turret playing with a cat.

Entertain Your Cats Automatically With LazerPaw

September 5, 2023 by Julian Scheffers 22 Comments

Most of us would agree that kittens are very cute, but require lots of attention in return. What would you do if you adopted three abandoned cats but didn’t have all day to play with them? [Hoani Bryson] solved his problem by building LazerPaw — an autonomous, safe way to let your cats chase lasers.

Having recently tinkered with computer vision in the form of OpenCV, [Hoani] decided he would make a laser turret for his cats to play with. An infrared camera, used so that the LazerPaw works in the dark, is mounted to the laser and the Raspberry Pi. These electronics are then mounted on a servo-based pan/tilt module, which is in turn mounted with two smartphone clamps to the ceiling. That way, when the cats chase the laser, they will be looking away from the beam source. Additionally, if the device is aiming directly at a cat, the laser is turned off. Finally, [Hoani] added some NeoPixels with an Arduino-based controller for extra hacker vibes.

The LazerPaw’s software takes in a 30 FPS stream from a webcam, scales it down for performance, and applies a threshold filter to it. When a black pixel, which is assumed to be a cat, is detected, it “pushes” the camera away from it depending on how close to the laser it is. The effect of this is that every time a cat catches up to the laser, it moves away again. The processed images are also sent to an interactive website for remote cat playtime. Finally, there is also a physical start button so you don’t need WiFi to use it.

Is your cat more of a sunbather than a deadly murder beast? Maybe it’ll like this cat chair that follows the sun.

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Heat Pump Control That Works

September 4, 2023 by Bryan Cockfield 33 Comments

Heat pumps are taking the world by storm, and for good reason. Not only are they many times more efficient than electric heaters, but they can also be used to provide cooling in the summer. Efficiency aside, though, they’re not perfectly designed devices, largely with respect to their climate control abilities especially for split-unit setups. Many of them don’t have remotely located thermostats to monitor temperature in an area, and rely on crude infrared remote controls as the only user interface. Looking to make some improvements to this setup, [Danilo] built a setup more reminiscent of a central HVAC system to control his.

Based on an ESP32 from Adafruit with an integrated TFT display, the device is placed away from the heat pump to more accurately measure room temperature. A humidity sensor is also included, as well as an ambient light sensor to automatically reduce the brightness of the display at night. A large wheel makes it quick and easy to adjust the temperature settings up or down. Armed with an infrared emitter, the device is capable of sending commands to the heat pump to more accurately control the climate of the room than the built-in controls are able to do. It’s also capable of logging data and integrating with various home automation systems.

While the device is optimized for the Mitsubishi heat pumps that [Danilo] has, only a few lines of code need to be changed to get this to work with other brands. This is a welcome improvement for those frustrated with the inaccurate climate controls of their heat pumps, and since it integrates seamlessly into home automation systems could also function in tandem with other backup heat sources, used in cold climates when it’s too cold outside to efficiently run the heat pump. And, if you don’t have a heat pump yet, you can always try and build your own.

Why Are We Only Just Now Hearing About LED Beaded Curtains

August 31, 2023 by Lewin Day 20 Comments

Beaded curtains are a pretty banal piece of home decor, unlikely to excite most interior design enthusiasts. Throw on some addressable LEDs, though, and you’ve got something eye-catching at the very least, as [Becky] demonstrates.

Joining the LED strands at the bottom made running the wiring easy but made walking through the blinds hard.

The project started with an existing beaded curtain as a base. A series of addressable LED strands were then carefully sewn to the beads using knots tied in plain sewing thread. The strands were configured as a single strand as far as the data lines were concerned, to make animation easy. Power was supplied to both ends of the strand to ensure nice and even brightness across the strands.

The brains of the system is a PixelBlaze controller, which makes it easy to wirelessly control the behavior of the strings. It’s the perfect tool for quickly whipping up fancy animations and pretty effects without hand-assembling a bunch of code yourself.

There was only a few problems with the project. [Becky] found a pretty passable LED beaded curtain from China midway through the project, which reduced her enthusiasm to finish the build. There were also issues walking through the curtain due to the wiring scheme she chose, where the bottom of one strand was connected to its neighbor.

Regardless, it’s a fun blinky build that brings some color to an otherwise drab doorway. It’s hard to complain about that! Video after the break.

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the PCB without the case on, showing the screen, battery, and removable sensor

2023 Hackaday Prize: A Reusable Plant Monitor

August 20, 2023 by Matthew Carlson 6 Comments

[Ovidiu] cares for their house plants, trying to dial in the perfect soil humidity and light levels. However, many cheap monitors tend to rust after a few weeks of sitting in a damp, slightly acidic environment. By creating a custom plant monitor with a removable probe, not only can [Ovidiu] integrate better with their Home Assistant setup, but it will also be less wasteful.

The build starts with an ESP32-S3, a TP4056 charging circuit, a small e-ink display, and an AHT20 IC for air humidity and temperature. The ESP32 reads the probe using the capacitance measuring devices for touchpads built into the chip. Or course, a 450mAh battery provides a battery life of about 11 days. The probe is just a bare PCB with a connector at the top, making them cheap and easy to swap. They included pads on the probe for a thermistor for reading soil temperature, but this is optional. A handsome 3D-printed case wraps it all up nicely.

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Smart Doorbell Focuses On Privacy

August 18, 2023 by Bryan Cockfield 11 Comments

As handy as having a smart doorbell is, with its ability to remotely see who’s at the front door from anywhere with an Internet connection, the off-the-shelf units are not typically known for keeping user privacy as a top priority. Even if their cloud storage systems were perfectly secure (which is not a wise assumption to make) they have been known to give governmental agencies and police free reign to view the videos whenever they like. Unfortunately if you take privacy seriously, you might need to implement your own smart doorbell yourself.

The project uses an ESP32-CAM board as the doorbell’s core, paired with a momentary push button and all housed inside a 3D-printed enclosure. [Tristam] provides a step-by-step guide, including printing the enclosure, configuring the ESP32-CAM to work with the popular open-source home automation system ESPHome, handling doorbell notifications automatically, and wiring the components. There are plenty of other optional components that can be added to this system as well, including things like LED lighting for better nighttime imaging.

[Tristam] isn’t much of a fan of having his home automation connected to the Internet, so the device eschews wireless connections and batteries in favor of a ten-meter USB cable connected to it from a remote machine. As far as privacy goes, this is probably the best of all worlds as long as your home network isn’t doing anything crazy like exposing ports to the broader Internet. It also doesn’t need to be set up to continuously stream video either; this implementation only takes a snapshot when the doorbell button is actually pressed. Of course, with a few upgrades to the ESP circuitry it is certainly possible to use these chips to capture video if you prefer.

Thanks to [JohnU] for the tip!