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!

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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.

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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.

A New, Smarter Universal Remote

May 6, 2025 by Matthew Carlson 21 Comments

The remote for [Dillan Stock]’s TV broke, so he built a remote. Not just as a replacement but as something new. For some of us, there was a glorious time in the early 2000s when a smart remote was needed and there were options you could buy off the shelf. Just one handy button next to the screen had a macro programmed that would turn on the receiver, DVD player, and TV, and then configure it with the right inputs. However, the march of technological convenience has continued and nowadays soundbars turn on just in time and the TV auto switches the input. Many devices are (for better or worse) connected to WiFi, allowing all sorts of automation.

[Dillan] was lucky enough that his devices were connected to his home assistant setup. So this remote is an ESP32 running ESPHome. These automations could be triggered by your phone or via voice assistant. What is more interesting is watching [Dillan] go through the design process. Deciding what buttons there should be, where they should be placed, and how the case would snap together takes real effort. The design uses all through-hole components except for the ESP32 which is a module.

This isn’t the first thing [Dillan] has made with an ESP32, as he previously revamped a non-standard smart lamp with the versatile dev board. The 3d printable files for the remote are free available. Video after the break.

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3D Printed Downspout Makes Life Just A Little Nicer

May 5, 2025 by Tyler August 13 Comments

Sometimes, a hack solves a big problem. Sometimes, it’s just to deal with something that kind of bugs you. This hack from [Dillan Stock] is in the latter category, replacing an ugly, redundant downspout with an elegant 3D printed pipe.

As [Dillan] so introspectively notes, this was not something that absolutely required a 3D print, but “when all you have a hammer, everything is a nail, and 3D printing is [his] hammer.” We can respect that, especially when he hammers out such a lovely print.

By modeling this section of his house in Fusion 360, he could produce an elegantly swooping loft to combine the outflow into one downspout. Of course the assembly was too big to print at once, but any plumber will tell you that ABS welds are waterproof. Paint and primer gets it to match the house and hopefully hold up to the punishing Australian sun.

The video, embedded below, is a good watch and a reminder than not every project has to be some grand accomplishment. Sometimes, it can be as simple as keeping you from getting annoyed when you step into your backyard.

We’ve seen rainwater collection hacks before; some of them a lot less orthodox. Of course when printing with ABS like this, one should always keep in mind the ever-escalating safety concerns with the material.

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