Lamp Sheds Light On Air Quality

It can be difficult to appreciate when the air quality is decent and when it’s poor, unless conditions are so bad that you can literally see the smog hanging in the air. Rather than try to digest a bunch of air quality numbers, [guillaume_slizewicz] built Canari — a lovely lamp that sheds light on the air pollution problem by taking local air quality data and turning it into light patterns.

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.

More of a numbers person? All you really need is a microcontroller, an air quality sensor, and a display.

Continue reading “Lamp Sheds Light On Air Quality”

A Raspberry Pi-Packing Cassette Powers This ZX Spectrum Emulator

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.

Few projects can demonstrate the advancement and miniaturization of computing technology like putting an entire functional computer inside a storage medium that once only held mere kilobytes of data. And that’s exactly what [JamHamster] has done by stuffing a Raspberry Pi Zero W inside a cassette tape to run his ZX Spectrum emulator. It’s an impressive and clean build, and it pairs so well with a downright gorgeous, retro inspired, CRT-lookalike LCD monitor, which is another creation of his.

A Raspberry Pi Zero with several areas lightly trimmed away inside an open cassette tape.

The Pi did have to undergo a bit of light surgery; though he managed to lose only four GPIO pins in the operation. He also put a ton of love into a literally-highly-polished aluminum heatsink, which is entirely hidden within the case but does keep the computer cool in its claustrophobic quarters. Of course, [JamHamster] isn’t new to these cassette builds. You may recognize his work from the TZXDuino, a virtual tape loader for the ZX Spectrum.

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.

Robotic Fish Swarm Together Using Cameras And LEDs

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.

Continue reading “Robotic Fish Swarm Together Using Cameras And LEDs”

Building The Ultimate Raspberry Pi Automation Controller

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.

Continue reading “Building The Ultimate Raspberry Pi Automation Controller”

Portable Video Looper Is Easy As Pi

We all have handfuls of thumb drives lying around with only a vague idea of what’s on most of them, right? So why not dust one off, back it up somewhere, and give it a new purpose? That’s exactly what [Cher_Guevara] did to make this portable Raspberry Pi video looper. The hardest part of recreating this one might be coming up with such a good candidate mini CRT TV.

Once powered on, the Pi Zero W stuffed inside this baby Magnavox waits for a thumb drive to be inserted and says as much in nice green text on the screen. Then it displays the number of video files found on the drive and gives a little countdown before looping them all endlessly.

We love how flawlessly [Cher] was able to integrate the USB port and a flush-mounted shutdown button for the Pi into the TV’s control panel on the top. It’s like a portable from another timeline.

[Cher] got lucky because this TV happens to have a video-in jack for connecting up the Pi. If yours doesn’t have one, you might be able to use an RCA to RF converter if the antenna is removable. We’ve got the demo video waiting for you after these messages.

Okay, that’s one thumb drive repurposed. Now find another and experiment with adding USB OtG to it.

Continue reading “Portable Video Looper Is Easy As Pi”

Raspberry Pi Plays A MIDI Tune Wherever You May Roam

MIDI controller keyboards are great because they let you control any synthesizer you plug them into. The only downside: you need a synthesizer to turn MIDI notes into actual sounds, slightly complicating some summer night campfire serenading. Not for [Geordie] though, who decided to build the nanoPi, a portable, MIDI instrument housing a Raspberry Pi.

Using a Korg nanoKEY2 USB MIDI controller as base for the device, [Geordie] took it apart and added a Raspberry Pi Zero W, a power bank to, well, power it, and a USB hub to connect a likewise added USB audio interface, as well as the controller itself. As the nanoKEY2 has a naturally slim shape, none of this would ever fit in it, so he designed and 3D printed a frame to extend its height. Rather than wiring everything up internally, he decided to route the power and data cable to the outside and connect them back to the device itself, allowing him to use both the power bank and the controller itself separately if needed.

On the software side, the Pi is running your common open source software synthesizer, Fluidsynth. To control Fluidsynth itself — for example to change the instrument — [Geordie] actually uses the Termius SSH client on his phone, allowing him also to shut down the Pi that way. While Fluidsynth’s built-in MIDI router could alternatively remap the nanoKEY2’s additional buttons, it appears the functionality is limited to messages of the same type, so the buttons’ Control Change messages couldn’t be remapped to the required Program Change messages. Well, there’s always the option to fit some extra buttons if needed. Or maybe you could do something clever in software.

As you may have noticed, the nanoPi doesn’t include any speaker — and considering its size, that’s probably for the best. So while it’s not a fully standalone instrument, it’s a nice, compact device to use with your headphones anywhere you go. And thanks to its flexible wiring, you could also attach any other USB MIDI controller to it, such as this little woodwind one, or the one that plays every pop song ever.

Continue reading “Raspberry Pi Plays A MIDI Tune Wherever You May Roam”

Easy Internet For Retro Computers With The PiModem

Retro computers are great, but what really makes a computer special is how many other computers it can talk to. It’s all about the network! Often, getting these vintage rigs online requires a significant investment in dusty old network cards from eBay and hunting down long-corrupted driver discs to lace everything together. A more modern alternative is to use something like PiModem to do the job instead.

PiModem consists of using a Raspberry Pi Zero W to emulate a serial modem, providing older systems with a link to the outside world. This involves setting up the Pi to use its hardware serial port to communicate with the computer in question. A level shifter is usually required, as well as a small hack to enable hardware flow control where necessary. It’s then a simple matter of using tcpser and pppd so you can talk to telnet BBSs and the wider Internet at large.

It’s a tidy hack that makes getting an old machine online much cheaper and easier than using hardware of the era. We’ve seen similar work before, too!