A 3D printed cat treat dispenser on a table with a laptop in the background and with a treat in it's tray and a cat on the left about to eat the treat.

Local IOT Cat Treat Dispenser

[MostElectronics], like many of us, loves cats, and so wanted to make an internet connected treat dispenser for their most beloved. The result is an ingenious 3D printed mechanism connected to a Raspberry Pi that’s able to serve treats through a locally run web application.

The inside of a 3d printed cat treat dispenser, showing the different compartments, shaft and wires running out the back.

From the software side, the Raspberry Pi uses a RESTful API that one can connect to through a static IP. The API is implemented as a Python Flask application running under a stand alone web server Python script. The web application itself keeps track of the number of treats left and provides a simple interface to dispense treats at the operators leisure. The RpiMotorLib Python library is used to control a 28BYJ-48 stepper motor through its ULN2003 controller module, which is used to rotate the inside shaft of the treat dispenser.

The mechanism to dispense treats is a stacked, compartmentalized drum, with two drum layers for food compartments that turn to drop treats. The bottom drum dispenses treats through a chute connected to the tray for the cat, leaving an empty compartment that the top drum can replenish by dropping its treats into through a staggered opening. Each compartmentalized treat drum layer provides 11 treats, allowing for a total of 22 treats with two layers stacked on top of each other. One could imagine extending the treat dispenser to include more drum layers by adding even more layers.

Source code is available on GitHub and the STL files for the dispenser are available on Thingiverse. We’ve seen cat electronic feeders before, sometimes with escalating consequences that shake us to our core and leave us questioning our superiority.

Video after the break!

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A smartphone-sized PCB is in a person's hand. A large blue chip package houses a 486 and the board has a SoundBlaster card and a 40 PIN Raspberry Pi Connector along one edge for attaching a Raspberry Pi Zero.

TinyLlama Is A 486 In Your Pocket

We love retrocomputing and tiny computers here at Hackaday, so it’s always nice to see projects that combine the two. [Eivind]’s TinyLlama lets you play DOS games on a board that fits in your hand.

Using the 486 SOM from the 86Duino, the TinyLlama adds an integrated Crystal Semiconductor audio chip for AdLib and SoundBlaster support. If you populate the 40 PIN Raspberry Pi connector, you can also use a Pi Zero 2 to give the system MIDI capabilities when coupled with a GY-PCM5102 I²S DAC module.

Audio has been one of the trickier things to get running on these small 486s, so its nice to see a simple, integrated solution available. [Eivind] shows the machine running DOOM (in the video below the break) and starts up Monkey Island at the end. There is a breakout board for serial and PS/2 mouse/keyboard, but he says that USB peripherals work well if you don’t want to drag your Model M out of the closet.

Looking for more projects using the 86Duino? Checkout ISA Sound Cards on 86Duino or Using an 86Duino with a Graphics Card.

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Hackaday Links: November 13, 2022

Talk about playing on hard mode! The news this week was rife with stories about Palmer Luckey’s murder-modified VR headset, which ostensibly kills the wearer if their character dies in-game. The headset appears to have three shaped charges in the visor pointing right at the wearer’s frontal lobe, and would certainly do a dandy job of executing someone. In a blog post that we suspect was written with tongue planted firmly in cheek, Luckey, the co-founder of Oculus, describes that the interface from the helmet to the game is via optical sensors that watch the proceeding on the screen, and fire when a certain frequency of flashing red light is detected. He’s also talking about ways to prevent the removal of the headset once donned, in case someone wants to tickle the dragon’s tail and try to quickly rip off the headset as in-game death approaches. We’re pretty sure this isn’t serious, as Luckey himself suggested that it was more of an office art thing, but you never know what extremes a “three commas” net worth can push someone to.

There’s light at the end of the Raspberry Pi supply chain tunnel, as CEO Eben Upton announced that he foresees the Pi problems resolving completely by this time next year. Upton explains his position in the video embedded in the linked article, which is basically that the lingering effects of the pandemic should resolve themselves over the next few months, leading to normalization of inventory across all Pi models. That obviously has to be viewed with some skepticism; after all, nobody saw the supply chain issues coming in the first place, and there certainly could be another black swan event waiting for us that might cause a repeat performance. But it’s good to hear his optimism, as well as his vision for the future now that we’re at the ten-year anniversary of the first Pi’s release.

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Keeping An Eye On Heating Oil

Energy costs around the world are going up, whether it’s electricity, natural gas, or gasoline. This is leading to a lot of people looking for ways to decrease their energy use, especially heading into winter in the Northern Hemisphere. As the saying goes, you can’t manage what you can’t measure, so [Steve] has built this system around monitoring the fuel oil level for his home’s furnace.

Fuel oil is an antiquated way of heating, but it’s fairly common in certain parts of the world and involves a large storage tank typically in a home’s basement. Since the technology is so dated, it’s not straightforward to interact with these systems using anything modern. This fuel tank has a level gauge showing its current percentage full. A Raspberry Pi is set up nearby with a small camera module which monitors the gauge, and it runs OpenCV to determine the current fuel level and report its findings.

Since most fuel tanks are hidden in inconvenient locations, it makes checking in on the fuel level a breeze and helps avoid running out of fuel during cold snaps. [Steve] designed this project to be reproducible even if your fuel tank is different than his. You have other options beyond OpenCV as well; this fuel tank uses ultrasonic sensors to measure the fuel depth directly.

PySpectrometer version 2, showing mini spectroscope, 4 inch display and hand for scale

Pi-based Spectrometer Gets An Upgrade

Here at Hackaday, we love to see projects re-visited and updated after we’ve covered them on the site. It’s always exciting to see what the creators come up with next, and this Pi-Based Spectrometer project is a great example of that.

[LesWright] found himself with a problem when the new version of Raspberry Pi operating system was released (Bullseye), and it broke some functionality on his original software. Rather than just fix the issues, [Les] chose to rewrite the software more dramatically and has ended up with a much more capable spectrometer that is able to match professional devices costing many times more.

Screenshot of Waterfall Display for PySpectrometer 2
Screenshot of Waterfall Display for PySpectrometer 2

By using multi-wavelength calibration and polynomial regression data, the new version is much more accurate and can now resolve wavelengths down to +/- 1nm.

The whole project is now written in OpenCV, and there’s a nifty new waterfall spectrum display, that will show changes in measured spectra over time.

A low-cost benchtop spectroscope is coupled to a RaspberryPi Camera via a CCTV zoom lens and the whole setup is mounted to a small block of aluminium for thermal and mechanical stability. The spectroscope is pointed at a fluorescent lamp and the user is guided through a calibration routine to tune the software to the hardware.

We’re impressed with the precision [Les] has achieved with his builds, and the write-up is sufficiently detailed to allow others to follow in his footsteps. We’d love to see if readers build one themselves, and what they use them for!

If you want to read up on the original build, you can find our article here. We’ve covered several spectrometry projects in the past, including this Gamma-Ray Spectrometer and this one based around an STM32 Nucleo board. Continue reading “Pi-based Spectrometer Gets An Upgrade”

Play DOOM On Seven-Segment Displays

Getting DOOM to run on a computer it was never meant to run on is a fun trope in the world of esoteric retro computers. By now we’ve seen it run on everything from old NES systems to microwaves, treadmills, and basically anything with a computer inside of it. What we don’t often see are the displays themselves being set up specifically to run the classic shooter. This build might run the game itself on ordinary hardware, but the impressive part is that it’s able to be displayed on this seven-segment display.

This build makes extensive use of multiplexers to drive enough seven-segment displays to use as a passable screen. There are 1152 seven segment digits arranged in a 48 by 24 array, powered by a network of daisy-chained MAX7219 chips. A Python script running on a Raspberry Pi correlates actual image data with the digit to be displayed on each of the segments, and the Raspberry Pi sends all of that information out to the screen. The final result is a display that’s fast enough and accurate enough to play DOOM in a truly unique way.

There is much more information available about this project on their project page, and they have made everything open source for those who wish to follow along as well. The project includes more than just the ability to play DOOM, too. There’s a built-in video player and a few arcade programs programmed specifically to make use of this display. Perhaps one day we will also see something like this ported to sixteen-segment displays instead of the more common seven-segment.

2022 Cyberdeck Contest: Prototype Cyberdeck Is Anything But Questionable

We see many projects here at Hackaday, about which their creators are unreasonably modest. We like a good cyberdeck, and we think [betaraybiff] is one of those creators from their project description for a Prototype Cyberdeck of Questionable Practical Use. It may be a prototype, but we think it could be quite a practical computer.

At its heart is the ubiquitous Raspberry Pi 4 paired with a PiSugar power supply and a minimalist mechanical keyboard. The case is the interesting part, because it’s well-designed to be 3D printed in sections with the HDMI display hinging up from above the keyboard. The Pi is open and visible on top of the deck, but this could easily be covered with another printed piece if desired.

So we disagree on the practicality, given a train journey and this cyberdeck we think we could easily crack out a Hackaday article or two. Never undersell your creations, like this one they’re almost certainly better than you think.

If you’d like to see more of the 2022 Cyberdeck Contest, take a look at the best of the best.