2025 Pet Hacks Contest: Keep Your Hound Toasty Warm With This Heated Dog Bed

May 23, 2025 by Jenny List 2 Comments

It’s been a universal trait among the different faithful Hackaday Hounds who have loped around these parts over the decades, that there is no place warm enough for their tastes. Fire up the stove and the dog is there stretched out in front of it, leaving one to wonder whether our house temperature is being cruel to the mutt, or simply that they are heat sponges with infinite capacity. There’s got to be some joy in doggy circles then at the prospect of [John.r.sheahan]’s heated dog bed, designed in particular with the comfort of an older dog in mind.

In electronics terms it’s a relatively low-tech project, using as it does a 12 volt electric lap blanket aimed at motorists. It’s none the less a hack though, because it has a frame made of PVC pipe to hold it, and a blanked clipped in place. This forms a box-like structure above the sleeping position keeping the dog very comfortable indeed over chilly nights. We’ve cared for more than one geriatric dog over the years, and can see that something like this is vital for their comfort and well-being.

This project is part of the 2025 Pet Hacks contest, so look out for more like it. Alternatively if your faithful friend uses something you made, why not enter yourself!

A high level pictorial schematic of the basement monitor.

Making Sure The Basement Stays Dry With An ESP8266

May 17, 2025 by John Elliot V 38 Comments

The hack we have for you today is among our most favorite types of hack: a good, honest, simple, and well documented implementation that meets a real need. Our hacker [Solo Pilot] has sent in a link to their basement monitor.

The documentation is quite good. It’s terse but comprehensive with links to related information. It covers the background, requirements, hardware design, sensors, email and SMS alerts, software details, and even has some credits at the end.

Implementing this project would be a good activity for someone who has already made an LED flash and wants to take their skills to the next level by sourcing and assembling the hardware and then configuring, compiling, deploying, and testing the software for this real-world project.

To make this project work you will need to know your way around the Arduino IDE in order to build the software from the src.zip file included with the documentation (hint: extract the files from src.zip into a directory called AHT20_BMP280 before opening AHT20_BMP280.ino and make sure you add necessary boards and libraries).

One feature of the basement monitor that we would like to see is a periodic “everything’s okay” signal from the device, just so we can confirm that the reason we’re not getting an alarm about flooding in the basement is because there is no flood, and not because the battery ran dead or the WiFi went offline.

If you’ve recently started on your journey into where electronics meets software a project such as this one is a really great place to go next. And of course once you are proficient with the ESP8266 there are a thousand such projects here at Hackaday that you can cut your teeth on. Such as this clock and this fault injection device.

The Screamer Is Just Like The Clapper But Even More Annoying

May 16, 2025 by Lewin Day 11 Comments

Remember The Clapper? It was a home automation tool (of sorts) that let you turn appliances on and off by clapping. [Kevin O’Connor] has built something rather similar, if more terrifying. It’s called The Screamer.

The build is based around a Sonoff S31 smart switch. [Kevin] selected an off-the-shelf device because he wanted something that was safe to use with mains power out of the box. But specifically, he selected the S31 because it has an ESP8266 inside that’s easy to reprogram with the aid of ESPHome. He ended up hooking up a whole extra ESP32 with an INMP441 microphone over I2S to do the scream detection. This was achieved with a simple algorithm that looked for high amplitude noises with lots of energy in the 1000 – 4000 Hz frequency range. When a scream is detected, it flips a GPIO pin which is detected by the S31, which then toggles the state of the smart switch in turn. Job done.

It’s a simple project that does exactly what it says on the tin. It’s The Screamer! If you’d like to learn more about the original Clapper that inspired this build, we’ve looked at that before, too. Meanwhile, if you’re cooking up your own excuses to scream at the lights and walls in your home, please only notify the tipsline if it has something vaguely to do with electronics or hackery.

Wireless Doorbell Extension Features Home-Wound Coil

May 16, 2025 by John Elliot V 12 Comments

Today in the it’s-surprising-that-it-works department we have a ding dong doorbell extension from [Ajoy Raman].

What [Ajoy] wanted to do was to extend the range of his existing doorbell so that he could hear it in his workshop. His plan of attack was to buy a new wireless doorbell and then interface its transmitter with his existing doorbell. But his approach is something others might not have considered if they had have been tasked with this job, and it’s surprising to learn that it works!

What he’s done is wrap a new coil around the ding dong doorbell’s solenoid. When the solenoid activates, a small voltage is induced into the coil. This then gets run into the wireless doorbell transmitter power supply (instead of its battery) via a rectifier diode and a filter capacitor. The wireless doorbell transmitter — having also had its push-button shorted out — operates for long enough from this induced electrical pulse to transmit the signal to the receiver. To be clear: the wireless transmitter is fully powered by the pulse from the coil around the solenoid. Brilliant! Nice hack!

We weren’t sure how reliable the transmitter would be when taken out of the lab and installed in the house so we checked in with [Ajoy] to find out. It’s in production now and operating well at a distance of around 50 feet!

Of course we’ve published heaps of doorbell hacks here on Hackaday before, such as this Bluetooth Low Energy (BLE) doorbell and this light-flashing doorbell. Have you hacked your own doorbell? Let us know on the tips line!

Continue reading “Wireless Doorbell Extension Features Home-Wound Coil” →

Smart Terrarium Run By ESP32

May 15, 2025 by Lewin Day 8 Comments

A terrarium is a little piece of the living world captured in a small enclosure you can pop on your desk or coffee table at home. If you want to keep it as alive as possible, though, you might like to implement some controls. That’s precisely what [yotitote] did with their smart terrarium build.

At the heart of the build is an ESP32 microcontroller. It’s armed with temperature and humidity sensors to detect the state of the atmosphere within the terrarium itself. However, it’s not just a mere monitor. It’s able to influence conditions by activating an ultrasonic fogger to increase humidity (which slightly impacts temperature in turn). There are also LED strips, which the ESP32 controls in order to try and aid the growth of plants within, and a small OLED screen to keep an eye on the vital signs.

It’s a simple project, but one that serves as a basic starting point that could be readily expanded as needed. It wouldn’t take much to adapt this further, such as by adding heating elements for precise temperature control, or more advanced lighting systems. These could be particularly useful if you intend your terrarium to support, perhaps, reptiles, in addition to tropical plant life.

Indeed, we’ve seen similar work before, using a Raspberry Pi to create a positive environment to keep geckos alive! Meanwhile, if you’re cooking up your own advanced terrarium at home, don’t hesitate to let us know.

2025 Pet Hacks Contest: Automatic Treat Dispenser Makes Kitty Work For It

May 14, 2025 by Tyler August 10 Comments

Treat dispensers are old hat around here, but what if kitty doesn’t need the extra calories — and actually needs to drop some pounds? [MethodicalMaker] decided to link the treat dispenser to a cat wheel, and reward kitty for healthy behaviors. The dispenser can be programmed to make the cat run long enough to burn the calories of its treat. Over time, kitty can be trained to run longer between treats to really melt off the pounds.

The wheel itself is an off the shelf model called “One Fast Cat”; apparently these are quite cheap second hand as most cats don’t really see the point in exercise. [MethodicalMaker] glued evenly-spaced magnets along the rim in order to track the rotation with a hall effect sensor. A microcontroller is watching said sensor, and is programmed to release the treats after counting off a set number of revolutions. Control over the running distance and manual treat extrusion is via web portal, but the networking code had difficulty on the Arduino R4 [MethodicalMaker] started with, so he switched to an ESP32 to get it working.

The real interesting part of this project is the physical design of the treat dispenser: it uses a double-auger setup to precisely control treat release. The first auger lives inside a hopper that holds a great many treats, but it tended to over-dispense so [MethodicalMaker] methodically made a second auger that sits beneath the hopper. The handful of treats extruded by the first auger are dispensed individually by the second auger, aided by a photosensor inside the exit chute to count treats. This also lets the machine signal when it needs refilling. For precise control, continuous servos are used to drive the augers. Aside from the electronics, everything is 3D printed; the STLs are on Printables, and the code is on GitHub.

If you don’t have a cat wheel, DIY is an option. If you don’t have a cat, we’ve also highlighted dog treat dispensers. If you don’t have either, check with your local animal shelter; we bet good money there are oodles ready to adopt in your town, and then you’ll have an excuse to enter one of your projects into our ongoing Pet Hacks Contest.

Continue reading “2025 Pet Hacks Contest: Automatic Treat Dispenser Makes Kitty Work For It” →

A Brain Transplant For A Philips Smart Lamp

May 14, 2025 by Tyler August 25 Comments

As the saying goes, modern problems require modern solutions. When the modern problem is that your smart light is being hijacked by the neighbors, [Wejn]’s modern solution is to reverse engineer and replace the mainboard.

The light in question is a Phillips Hue Ambiance, and [Wejn]’s excellently-documented six part series takes us through the process of creating a replacement light driver. It’s a good read, including reverse-engineering the PWM functions to get the lights to dim exactly like stock, and a dive into the Zigbee protocol so his rebuild light could still talk to the Philips Hue hub. The firmware [Wejn] wrote for the ESP32C6 he chose to use for this project is on GitHub, with the PCB in a second repo.

We want to applaud [Wejn] for his excellent documentation and open-sourcing (the firmware and PCB are under GPL v3). Not only do we get enough information to replicate this project perfectly if we so choose, but by writing out his design process, [Wejn] gives everyone reading a good head start in doing something similar with other hardware. Even if you’re scratching your head wondering why a light switch isn’t good enough anjymore, you have to appreciate what [Wejn] is offering the community.

We’ve covered domestic brain transplants in the past — which is easier in this sort of light than the close confines of a smart bulb. If you’re still wondering why not just use a light switch, perhaps you’d rather hack the light to run doom instead.

Before you go, can we just take a moment to appreciate how bizarre the world has become that we have a DOOM-capable computer to run fancy light fixture? If you’re using what might have been a decent workstation in days of yore to perform a painfully mundane task, let us know on the tips line.