Announcing The 2025 Hackaday One Hertz Challenge

June 26, 2025 by Elliot Williams 19 Comments

It’s about time! Or maybe it’s about time’s reciprocal: frequency. Whichever way you see it, Hackaday is pleased to announce, just this very second, the 2025 One Hertz Challenge over on Hackaday.io. If you’ve got a device that does something once per second, we’ve got the contest for you. And don’t delay, because the top three winners will each receive a $150 gift certificate from this contest’s sponsor: DigiKey.

What will you do once per second? And how will you do it? Therein lies the contest! We brainstormed up a few honorable mention categories to get your creative juices flowing.

Timelords: How precisely can you get that heartbeat? This category is for those who prefer to see a lot of zeroes after the decimal point.
Ridiculous: This category is for the least likely thing to do once per second. Accuracy is great, but absurdity is king here. Have Rube Goldberg dreams? Now you get to live them out.
Clockwork: It’s hard to mention time without thinking of timepieces. This category is for the clockmakers among you. If your clock ticks at a rate of one hertz, and you’re willing to show us the mechanism, you’re in.
Could Have Used a 555: We knew you were going to say it anyway, so we made it an honorable mention category. If your One Hertz project gets its timing from the venerable triple-five, it belongs here.

We love contests with silly constraints, because you all tend to rise to the challenge. At the same time, the door is wide open to your creativity. To enter, all you have to do is document your project over on Hackaday.io and pull down the “Contests” tab to One Hertz to enter. New projects are awesome, but if you’ve got an oldie-but-goodie, you can enter it as well. (Heck, maybe use this contest as your inspiration to spruce it up a bit?)

Time waits for no one, and you have until August 19th at 9:00 AM Pacific time to get your entry in. We can’t wait to see what you come up with.

Announcing The 2025 Pet Hacks Winners

June 24, 2025 by Elliot Williams 9 Comments

When you really love your pawed, feathered, or scaled friends, you build projects for them. (Well, anyway, that’s what’s happened to us.) For the 2025 Pet Hacks Challenge, we asked you to share your favorite pet-related hacks, and you all delivered. So without further ado, here are our favorites, as well as the picks-of-the-litter that qualified for three $150 DigiKey gift certificates. Spoiler alert: it was a clean sweep for team cat.

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2025 Pet Hacks Contest: Cat At The Door

June 12, 2025 by Matt Varian 14 Comments

This Pet Hacks Contest entry from [Andrea] opens the door to a great collaboration of sensors to solve a problem. The Cat At The Door project’s name is a bit of a giveaway to its purpose, but this project has something for everyone, from radar to e-ink, LoRa to 3D printing. He wanted a sensor to watch the door his cats frequent and when one of his cats were detected have an alert sent to where he is in the house

There are several ways you can detect a cat, in this project [Andrea] went with mmWave radar, and this is ideal for sensing a cat as it allows the sensor to sit protected inside, it works day or night, and it doesn’t stop working should the cat stand still. In his project log he has a chapter going into what he did to dial in the settings on the LD2410C radar board.

How do you know if you’re detecting your cat, some other cat, a large squirrel, or a small child? It helps if you first give your cats a MAC address, in the form of a BLE tag. Once the radar detects presence of a suspected cat, the ESP32-S3 starts looking over Bluetooth, and if a known tag is found it will identify which cat or cats are outside waiting.

Once the known cat has been identified, it’s time to notify [Andrea] that his cat is waiting for his door opening abilities. To do this he selected an ESP32 board that includes a SX1262 LoRa module for communicating with the portable notification device. This battery powered device has a low power e-paper display showing you which cat, as well as an audio buzzer to help alert you.

To read more details about this project head over to the GitHub page to check out all the details. Including a very impressive 80 page step-by-step guide showing you step by step how to make your own. Also, be sure to check out the other entries into the 2025 Pet Hacks Contest.

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2025 Pet Hacks Contest: Fort Bawks Is Guarded By Object Detection

June 9, 2025 by Tyler August 5 Comments

One of the difficult things about raising chickens is that you aren’t the only thing that finds them tasty. Foxes, raccoons, hawks — if it can eat meat, it probably wants a bite of your flock. [donutsorelse] wanted to protect his flock and to be able to know when predators were about without staying up all night next to the hen-house. What to do but outsource the role of Chicken Guardian to a Raspberry pi?

Object detection is done using a YOLOv8 model trained on images of the various predators local to [donutorelse]. The model is running on a Raspberry Pi and getting images from a standard webcam. Since the webcam has no low-light capability, the system also has a motion-activated light that’s arguably goes a long way towards spooking predators away itself. To help with the spooking, a speaker module plays specific sound files for each detected predator — presumably different sounds might work better at scaring off different predators.

If that doesn’t work, the system phones home to activate a siren inside [donutorelse]’s house, using a Blues Wireless Notecarrier F as a cellular USB modem. The siren is just a dumb unit; activation is handled via a TP-Link smart plug that’s hooked into [donutorelse]’s custom smart home setup. Presumably the siren cues [donutorelse] to take action against the predator assault on the chickens.

Weirdly enough, this isn’t the first time we’ve seen an AI-enabled chicken coop, but it is the first one to make into our ongoing challenge, which incidentally wraps up today.

2025 Pet Hacks Contest: Weigh Your Dog The Easy Way

June 1, 2025 by Jenny List 4 Comments

If you need to weigh your pet, you’ll soon find that getting an animal to stand on a weighing machine to order is very difficult indeed. If the critter in question is a cat or a small dog you can weigh yourself both holding them and not holding them, and compute the difference. But in the case of a full size Bernese mountain dog, the hound is simply too big for that. Lateral thinking is required, and that’s how [Saren Tasciyan] came up with the idea of making a dog bed that’s also a weighing machine. When the mutt settles down, the weight can be read with ease. The bed itself is a relatively straightforward wooden frame, with load cells placed above rubber feet. The load cells in turn talk to an ESP8266 which has an LCD display to deliver the verdict. Dog weighed, without the drama.

This project is of course part of the Hackaday 2025 Pet Hacks contest, an arena in which any of the cool hacks you’ve made to enhance you and your pet’s life together can have an airing. Meanwhile this isn’t the first time this particular pooch has had a starring role; he’s sported a rather fetching barrel in a previous post.

2025 Pet Hacks Contest: Keep The Prey At Bay With The Cat Valve

May 30, 2025 by Jenny List 11 Comments

Some cats are what you might call indoor cats, happy to stretch out in the lap of indoor luxury and never bother themselves with the inclement outdoors again. Others however are fully in touch with their Inner Cat, and venture forth frequently in search of whatever prey they can find.

[Rkramer] has a cat of this nature,sadly one with a propensity for returning with live prey. To avoid this problem a solution is called for, and it comes in the shape of the Cat Valve, an automated cat door which enforces a buffer zone in their cellar to prevent unwanted gifts.

It’s a simple enough idea, when an IR sensor connected to a Raspberry Pi 4 detects the cat heading out into the world through the exterior cat flap, the computer fires up a motor connected to a lead screw which closes the flap between buffer zone and house. The cat then has the safety of the buffer zone, but can’t bring the prey fully inside.

If you’re a cat lover you’ll forgive them anything, but we have to admit to being on [Rkramer]’s side with this one. A useful way to keep the prey at bay is something we could have used a few times in the past, too. This project is part of the 2025 Pet Hacks contest. Done something similar for your cat? Why not make it an entry!

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

May 29, 2025 by Tyler August 6 Comments

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.