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

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”

Announcing The Hackaday Pet Hacks Contest

A dog may be man’s best friend, but many of us live with cats, fish, iguanas, or even wilder animals. And naturally, we like to share our hacks with our pets. Whether it’s a robot ball-thrower, a hamster wheel that’s integrated into your smart home system, or even just an automatic feeder for when you’re not home, we want to see what kind of projects that your animal friends have inspired you to pull off.

The three top choices will take home $150 gift certificates from DigiKey, the contest’s sponsor, so that you can make even more pet-centric projects. You have until May 27th to get your project up on Hackaday.io, and get it entered into Pet Hacks.

Continue reading “Announcing The Hackaday Pet Hacks Contest”

students overlooking their rope-traversing robots

Crawler Challenge: Building Rope-Traversing Robots

Rope-climbing robots are the stuff of engineering dreams. As kids, didn’t we all clutter our family home with constructions of towers and strings – Meccano, or Lego – to have ziplines spanning entire rooms? Good for the youngsters of today, this has been included in school curricula. At the University of Illinois, the ME 370 students have been given the task of building a robot that can hang from a rope and walk across it—without damaging the rope. The final projects show not only how to approach tricky design problems, but also the creative solutions they stumbled upon.

Imagine a tiny, rope-climbing walker in your workshop—what could you create?

The project is full of opportunities for those thinking out of the box. It’s all about the balance between innovation and practicality: the students have to come up with a solution that can move at least 2 meters per minute, fits in a shoebox, and has some creative flair—no wheels allowed! The constraints provide an extra layer of challenge, but that’s where the fun lies. Some students use inverted walkers, others take on a more creature-like approach. The clever use of motors and batteries shows just how far simple tech can go when combined with a bit of engineering magic.

This project is a fantastic reminder that even small, seemingly simple design challenges can lead to fascinating creations. It invites us adults to play, and by that, we learn: a win-win situation. You can find the original article here, or grab some popcorn and watch the video below.

Continue reading “Crawler Challenge: Building Rope-Traversing Robots”

Supercon Add-On Add-Ons in production.

2024 SAO Contest: We’ve Got SAOs For Your SAOs

So, we heard you like SAOs. How about some SAOs for your SAO? That’s exactly what’s going on here with [davedarko]’s SAOAO — introducing the Supercon Add-On Add-On standard, which is inspired by another minibadge standard by [lukejenkins]. At most, an SAOAO is 19×19 mm and features a 1.27 mm 3-pin header. As [davedarko] says, no pressure to do I²C, just bring the vibes.

All SAOAOs use the Yo Dawg SAO baseplate, which has room for three SAOAOs. Because six pins is often too many to make a few LEDs light up, the SAOAO standard uses a mere three pins. Not only are SAOAOs easier to route, the pins can’t even be mirrored accidentally because VCC is in the middle, and both outside pins are grounds.

Want to get your hands on some of these bad boys? [davedarko] is bringing 100 Yo Dawg SAO baseplates and 200 SAOAOs to Supercon. But if you want to make your own, you are more than welcome to do so.

A render of an SAO that resembles a Speak 'n Spell.

2024 SAO Contest: Speak, SAO

For some of us, the Speak ‘n Spell evokes pleasant memories of childhood as our first computer, along with one of those Merlin things. For others, it’s the ultimate circuit bending victim. For [Jeremy Geppert], they’re all-around good fun and he wanted to immortalize the device in a Simple Add-On (SAO).

This is [Jeremy]’s first board and SAO rolled into one, motivated by both Supercon and the SAO Contest. To start things off, [Jeremy] scaled down the design we all know and love to fit a 128×32 OLED display, and it looks great. The plan is to have the display, an amplified speaker, and a single button for input.

Before committing the board order, [Jeremy] had a brief freak-out about the pin distance as it relates to the window for the OLED display. Luckily, his brother suggested checking things first by printing a 1:1 scale image of the board outline, and laying that over the display.

This is the week it all comes together, as the tiny switches and (regular-size) connectors have arrived, and the boards are due quite soon. Go, [Jeremy], go!

A golden Jolly Wrencher SAO that works as an NFC tag for sharing contact info.

2024 SAO Contest: The Jolly Tagger Is A Golden Way To Share Info

For this contest, we’re asking you to come up with the best SAO you can think of that does something cool. What could be cooler than sharing your contact information all over Supercon and beyond with a tap of a Jolly Wrencher? It’s way better than just some sticker, and with the extra solder pad on the back, you can turn it into a pin once the con is over. Contact data can be uploaded over I²C.

An antenna coil PCB trace as generated by a KiCad plugin.
The KiCad-generated coil.

Here, [Phil Weasel] seeks to answer the question of whether one can make a working NFC tag with the M24LR04E IC, using a PCB trace as a coil. If there is an issue, it’s probably going to be that copper plane inside the antenna.

Designing the antenna itself proved fairly easy after checking the datasheet for the internal tuning capacitance (~27.5 pF), verifying the frequency of NFC (~13.56 MHz), and doing the math to find the inductance needed. After confirming everything in LTSpice, [Phil] used a PCB coil calculator and let the KiCad coil generator draw it out.

Did we mention the Jolly Wrencher is backlit by four side-mounted LEDs? Because what’s an SAO without a few blinkenlights?

Meet The Winners Of The 2024 Tiny Games Contest

Over the years, we’ve figured out some pretty sure-fire ways to get hackers and makers motivated for contests. One of the best ways is to put arbitrary limits on different aspects of the project, such as how large it can be or how much power it can consume. Don’t believe us? Then just take a look at the entries of this year’s Tiny Games Contest.

Nearly 80 projects made it across the finish line this time, and our panel of judges have spent the last week or so going over each one to try and narrow it down to a handful of winners. We’ll start things off with the top three projects, each of which will be awarded a $150 gift certificate from our friends at DigiKey.

First: Sub-Surface Simon

While this contest saw a lot of excellent entries, we don’t think anyone is going to be surprised to see this one take the top spot. Earning an exceptionally rare perfect ten score from each of our judges, Sub-Surface Simon from [alnwlsn] grabbed onto the theme of this contest and ran like hell with it. Continue reading “Meet The Winners Of The 2024 Tiny Games Contest”