Sometimes daily tasks, like feeding pets, can feel like a real chore. To help with alleviate the mundane aspects of daily life, [Erik Berglund] has created an automatic fish feeder, complete with 3D print files, firmware, and an Android app for complete control over scheduling and feeding.
The mechanics of the fish feeder include a screw conveyor system that pushes the food pellets fed from a food store basin. The screw conveyor is driven by a Feetech FS5106R servo which provides enough force to overcome jamming that might occur with pellets getting stuck in the conveyor system. [Erik Berglund] writes that the system can dispense about 0.9 g/s and that it’s designed for granulated food, as flakes have problems because “their low density and large surface area tend to get them stuck in the throat of the hopper” — an issue that we’ve looked into previously.
[Erik Berglund] used [coberdas]’s fish feeder as the base, upgrading it with a better servo, adding a Raspberry Pi Zero W along with software for the Pi and an Android application to control the schedule of feedings. There’s also a DS1307 real time clock module to keep precision time and a push button for “manual” feeding. If you’re looking to follow along at home, you can find the Python scripts that run on the Pi and the source code for the Android application in their respective GitHub repositories.
A few decades ago, palmtop computers were mostly based on MS-DOS, and while many users tried to mimic the UNIX experience, the results were mixed. Fast forward to the present and business-card-sized Linux computers modules abound. Canadian tinkerer [Rune Kyndal] decided to make his own Linux palmtop by sacrificing an old HP-95LX and replacing the guts with a Raspberry Pi Zero and a color LCD screen. We’re impressed with the rich set of features he has crammed into the limited volume of the case:
Raspberry Pi Zero W
Color LCD, 4.3 inch, 800×480 w/Backlight
Capacitive touch screen (not connected yet)
Stereo speakers + microphone
USB 2.0, 2 each
RS-232, DE-9 connector
LiPo Battery w/Charger
One problem that any palmtop faces is how to make a usable keyboard, and HP had one of the better designs. The keys are the same famous style as used in HP calculators. And while no human with normal hands could touch-type on it, the keyboard’s layout and tactile feel was well-suited to “thumb typing”. [Rune] made a good decision by keeping the original keyboard.
While fully functional, this is more of a proof of concept than a polished project. [Rune] primarily used bits and pieces that he had laying around. [Rune] says if he did it again, he would replace all the hot-glued accessory parts with a custom PCB, which is probably good advice. If you want to make your own, check out the project comments for some suggestions.
[production] cites several previous, similar projects that showed how to interface with the click-wheel, a perfectly fitting color display from Waveshare, and open-source software called Rockbox to run on the pi. We all stand on the shoulders of giants.
Some nice innovations to look for are the Pi Zero’s micro-SD card and a micro-USB charging port aligned to the large slot left from the iPod’s original 40 pin connector. Having access for charging and reflashing the card without opening the case seems quite handy. There’s a nice sized battery too, though we wonder if a smaller battery and a Qi charger could fit in the same space. Check the project’s Hackaday.io for the parts list, and GitHub for the software side of things, and all the reference links you’ll need to build your own. It looks like [production] has plans to turn old iPods into Gameboy clones, you may want to check back for progress on that.
Canari is of course named after the brave birds that once alerted miners to dangerous air conditions before they were forced to switch to carbon monoxide sensors. This bird has a Raspberry Pi Zero W that gets air quality data from a public API and controls the lights with a PWM bonnet based on the concentration of particulates in the air. The more particulates, the dimmer the LEDs are, and the faster they fade in and out.
The main piece of data that Canari grabs is the amount of particulate matter, and the display can switch between representing the level of PM2.5 (particulate matter with diameter less than 2.5 micrometers) in the air and PM10. Check out the demo and setup video after the break.
Sometimes we are vaguely aware of the inexorable march of technological progress. Other times it thrums steadily under the surface while we go about our lives. And sometimes, just sometimes, it smacks us right in the face.
Honestly, sometimes we just have to sit back and be amazed at the kind of computer power that can be packed into such tiny packages. The Pi Zero isn’t the smallest or the most powerful of options, but it is far more capable than the computer it is emulating here. So whether they’re hiding inside outdated storage formats or powering a stock-looking sleeper PSP, we just can’t help but be impressed.
Robotics has advanced in leaps and bounds over the past few decades, but in terms of decentralized coordination in robot swarms, they far behind biological swarms. Researchers from Harvard University’s Weiss Institute are working to close the gap, and have developed Blueswarm, a school of robotic fish that can exhibit swarm behavior without external centralized control.
In real fish schools, the movement of an individual fish depends on those around it. To allow each robotic fish to estimate the position of its neighbors, they are equipped with a set of 3 blue LEDs, and a camera on each side of the body. Four oscillating fins, inspired by reef fish, provide 3D control. The actuator for the fins is simply a pivoting magnet inside a coil being fed an alternating current. The onboard computer of each fish is a Raspberry Pi W, and the cameras are Raspberry Pi Camera modules with wide-angle lenses. Using the position information calculated from the cameras, the school can coordinate its movements to spread out, group together, swim in a circle, or find an object and then converge on it. The full academic article is available for free if you are interested in the details.
Communication with light is dependent on the clarity of the medium it’s traveling through, in this case, water — and conditions can quickly become a limiting factor. Submarines have faced the same challenge for a long time. Two current alternative solutions are ELF radio and sound, which are both covered in [Lewin Day]’s excellent article on underwater communications.
At this point, we’ve lost count of how many automation projects we’ve seen with some variant of a Raspberry Pi at the helm. Which is hardly surprising, as the boards are cheap, powerful, and well documented. The list of reasons not to use one has never been very long, but with the PiCon One that [Frank] has been working on, it’s about to get even shorter.
The project takes the form of an IP65 industrial enclosure and support electronics that the Raspberry Pi Zero W plugs into. While expandable in nature, [Frank] has a core set of features he’s aiming for as a baseline such as additional serial ports, integrated uninterruptible power supply, a battery-backed Real Time Clock (RTC), an array of programmable status LEDs, and support for XBee and GPS plug-in modules. Feedback is provided through a pair of four digit seven-segment displays and a color 320×480 TFT screen running a custom user interface.
[Frank] envisions the PiCon One for use as a rugged solar power controller, eventually able to measure array output, energy consumption, and even operate motorized mounts to keep the panels pointed at the sun. To that end, he’s recently been experimenting with running JPL’s Horizon software on the Pi to determine the sun’s position in real-time. But the device is capable of so much more, and would make an ideal controller for many home and potentially even industrial applications.