Tidy LED Matrix Displays GIFs On Demand

When it comes to LED matrixes, building one is just the first step. Then you have to decide what to display on it. [panjanek] came up with a relatively flexible answer to this question, building an RGB LED matrix that can display the GIFs of your choice.

The web interface accepts GIFs for display.

[panjanek] grabbed WS2812B addressable LEDs for this project, assembling them into a 32 x 32 matrix that fits perfectly inside an off-the-shelf Ikea picture frame. The matrix is hooked up to an ESP8266 microcontroller, which acts as the brains of the operation. The WiFi-enabled microcontroller hosts its own web interface, with which the project can be controlled. Upon opening the page, it’s possible to upload a GIF file that will be displayed as an animation on the matrix itself. It’s also possible to stream UDP packets of bitmap data to the device to send real-time animations over a network.

It’s a neat build, and one that answers any questions of what you might display on your LED matrix when you’re finished assembling it. Code is on Github if you fancy implementing the GIF features in your own work. We’ve featured some unexpected LED matrix builds of late, like this innovative device for the M.2 slot. Meanwhile, if you’re cooking up your own creative LED builds, don’t hesitate to let us know on the tipsline!

2025 Pet Hacks Challenge : Poopopticon Is All Up In Kitty’s Business

After seeing this project, we can say that [James] must be a top-tier roommate. He has two flatmates– one human, one feline, and the feline flatmate’s litterbox was located in a bathroom close to the other human’s room. The odors were bothersome. A bad roommate might simply say that wasn’t their problem, but not [James].

Instead, he proclaimed “I shall build a poopopticon to alert me so I may clean the litterbox immediately, before smells can even begin to occur, thus preserving domestic harmony!”* We should all aspire to be more like [James].

It was, admittedly, a fairly simple project. Rather than dive into feline facial recognition, since it only has to detect a single cat, [James] used a simple IR sensor out of his parts bin, the sort you see on line-following robots. The microcontroller, an ESP8266, also came from his parts bin, making this project eligible for the ‘lowest budget’ award, if the contest had one.

The ESP8266 is set to send a message to a waiting webhook. In this case it is linked to a previous project, a smart ‘ring light’ [James] uses to monitor his Twitch chats. He’s also considered hooking it up to his lazy-esp32-banner for a big scrolling ‘change the litterbox!’ message. Since it’s just a webhook, the sky is the limit. Either way, the signal gets to its recipient and the litter gets changed before it smells, ensuring domestic bliss at [James]’ flat. If only all our roommates had been more like [James], we’d be much less misanthropic today.


  • He did not, in fact, say that.
Aquassist fish feeder

2025 Pet Hacks Contest: Aquassist Fish Feeder

This project submitted to the 2025 Pet Hacks Contest brings a bit of IoT to your finned friends. Aquassist is a fish feeder that is primarily 3D printed only requiring a servo and a microcontroller to give you remote control of feeding your fish.

The Aquassist consists of just six 3D-printed parts. At its core is an Archimedes screw, a mechanism that ensures consistent portions of fish food are dispensed into the fish tank. A small hopper on top holds the food, and to minimize the part count, all 3D-printed components are designed to be glued together.

The brains of the operation take place in a Wemos D1 mini, a compact ESP8266 board programed using the Arduino IDE. The feeding mechanism relies on an SG90 continuous rotation servo, which rotates the Archimedes screw to dispense food. Unlike standard servos, this model offers ample torque in a small package and can rotate continuously without hitting an angular limit.

The Aquassist is controlled via a web-based application accessible from any device. The D1 Mini connects to Firebase to check the feeding schedule or detect if the “Feed Now” button has been pressed. Users can set feeding times or trigger an immediate feeding through the app’s intuitive interface. Check out a video below to see the Aquassist in action, and check our our other entries into the 2025 Pet Hacks Contest.

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Trashed Sound System Lives To Rock Another Day

Plenty of consumer goods, from passenger vehicles to toys to electronics, get tossed out prematurely for all kinds of reasons. Repairable damage, market trends, planned obsolescence, and bad design can all lead to an early sunset on something that might still have some useful life in it. This was certainly the case for a sound system that [Bill] found — despite a set of good speakers, the poor design of the hardware combined with some damage was enough for the owner to toss it. But [Bill] took up the challenge to get it back in working order again.

Inside the DIY control unit.

The main problem with this unit is that of design. It relies on a remote control to turn it on and operate everything, and if that breaks or is lost, the entire unit won’t even power on. Tracing the remote back to the control board reveals a 15-pin connector, and some other audio sleuths online have a few ways of using this port to control the system without the remote.

[Bill] found a few mistakes that needed to be corrected, and was eventually able to get an ESP8266 (and eventually an ESP32) to control the unit thanks largely to the fact that it communicates using a slightly modified I2C protocol.

There were a few pieces of physical damage to correct, too. First, the AC power cable had been cut off which was simple enough to replace, but [Bill] also found that a power connector inside the unit was loose as well. With that taken care of he has a perfectly functional and remarkably inexpensive sound system ready for movies or music. There are some other options available for getting a set of speakers blasting tunes again as well, like building the amplifier for them from scratch from the get-go.

A high level pictorial schematic of the basement monitor.

Making Sure The Basement Stays Dry With An ESP8266

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

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.

Atomic Clock Trades Receiver For An ESP8266

The advantage of a radio-controlled clock that receives the time signal from WWVB is that you never have to set it again. Whether it’s a little digital job on your desk, or some big analog wall clock that’s hard to access, they’ll all adjust themselves as necessary to keep perfect time. But what if the receiver conks out on you?

Well, you’d still have a clock. But you’d have to set it manually like some kind of Neanderthal. That wasn’t acceptable to [jim11662418], so after he yanked the misbehaving WWVB receiver from his clock, he decided to replace it with an ESP8266 that could connect to the Internet and get the current time via Network Time Protocol (NTP).

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