Solar-powered pendant chirps like a bird.

BEAM Bird Pendant Really Chirps

December 9, 2021 by Kristina Panos 16 Comments

[NanoRobotGeek] had a single glorious weekend between the end of the term and the start of exams. Did they buy a keg and party it up? No, in fact, quite the opposite — they probably gained a few brain cells by free-form soldering this beautiful chirping bird pendant at 0603 instead.

The circuit is a standard BEAM project built around a 74HC14, but [NanoRobotGeek] made a few changes to achieve the ideal chirp sound. As you can see in the video after the break, it chirps for around 30 seconds and then shuts off for 1-2 minutes before starting up again.

What is better than a BEAM project? A portable one, we say. Although the chirping would probably get old pretty quickly, there’s just no substitute for working so small that you can carry it around your neck and show it off.

This one is kind of a long time coming, because [NanoRobotGeek] started by breadboarding the circuit and then made a PCB version way back in 2019, which they were attempting to miniaturize with this project. We think they did a fantastic job of it, and the documentation is stellar if you are crazy enough to attempt this one. You will need a lot of blu tack and patience, and pre-tinning is your friend. Be sure to check out the demo after the break.

The name checks out, and this isn’t [NanoRobotGeek]’s first foray into tiny circuit sculpture — just take a look at all we’ve covered.

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BFree Brings Intermittent Computing To Python

September 29, 2021 by Tom Nardi 16 Comments

Generally speaking, we like our computing devices to remain on and active the whole time we’re using them. But there are situations, such as off-grid devices that run on small solar cells, where constant power is by no means a guarantee. That’s where the concept of intermittent computing comes into play, and now thanks to the BFree project, you can develop Python software that persists even when the hardware goes black.

Implemented as a shield that attaches to a Adafruit Metro M0 Express running a modified CircuitPython interpreter, BFree automatically makes “checkpoints” as the user’s code is running so that if the power is unexpectedly cut, it can return the environment to a known-good state instantaneously. The snapshot of the system, including everything from the variables stored in memory to the state of each individual peripheral, is stored on the non-volatile FRAM of the MSP430 microcontroller on the BFree board; meaning even if the power doesn’t come back on for weeks or months, the software will be ready to leap back into action.

In addition to the storage for system checkpoints, the BFree board also includes energy harvesting circuity and connections for a solar panel and large capacitor. Notably, the system has no provision for a traditional battery. You can keep the Metro M0 Express plugged in while developing your code, but once you’re ready to test in the field, the shield is in charge of powering up the system whenever it’s built up enough of a charge.

The product of a collaboration between teams at Northwestern University and Delft University of Technology, BFree is actually an evolution of the battery-free handheld game they developed around this time last year. While that project was used to raise awareness of how intermittent computing works, BFree is clearly a more flexible platform, and is better suited for wider experimentation.

We’ve seen a fair number of devices that store up small amounts of energy over the long term for quick bouts of activity, so we’re very interested to see what the community can come up with when that sort of hardware is combined with software that can be paused until its needed.

Green Roofs Could Help Improve Solar Panel Efficiency

September 20, 2021 by Lewin Day 83 Comments

There’s been a movement in architecture over the past couple of decades to help tie together large urban developments with plant life and greenery. We’ve seen a few buildings, and hundreds more renders, of tall skyscrapers and large buildings covered in vegetation.

The aesthetic is often a beautiful one, but the idea is done as much for its tangible benefits as for the sheer visual glory. Naturally, there’s the obvious boost from plants converting carbon dioxide into delicious, life-giving oxygen. However, greenery on the roofs of buildings could also help improve the output of solar installations, according to a recent study from Sydney, Australia.

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Solar Display Case Is A Portable Triple Monitor Setup

August 15, 2021 by Lewin Day 10 Comments

They say once you start using twin monitors on the desktop, you’ll never want to go back. It’s even worse when you upgrade to three or more. However, it can be difficult to take such a set up on the road. Desiring better productivity on the go is what spurred [Brian Whitsett] to develop the Solar Display Case to solve this problem.

The Solar Display Case aims to pack three 17″ full-size monitors into a portable waterproof case. Brian has already built a prototype, which puts the monitors on folding arms so that they can be quickly stowed or deployed when needed.

The build also relies on solar power to charge batteries, in order to make the solution as portable as any laptop or other hardware you may be using with it. It’s no good having three mains-powered monitors sitting in the field with no AC power, after all. [Brian] aims to use a flexible solar panel to make the most of the surface area of the deployed assembly, for maximum power generation.

It’s a great project, and one we’d love to see fleshed out to the fullest. Imagining a briefcase that folds out into a triple-monitor workstation is exciting, and it looks like [Brian] is well on the way to making it a reality.

Building A Solar Powered Game Boy Pocket

August 8, 2021 by Matthew Carlson 5 Comments

Light has always been a key part of the classic Game Boy experience. Some of us have fond memories of riding along in the back seat of a car at night, pausing and unpausing the game as the street lights overhead briefly give enough light to see the unlit display. The availability of third party IPS displays for these classic handhelds has largely eradicated this problem today, but as you might expect, the increased power requirements of the more modern screen reduces the system’s runtime.

As part of their examination into energy production, the [Houston Museum of Natural Science] set out to see if they could improve things by adding a solar panel to the back of a Game Boy Pocket that had already been modified with an IPS display. The Pocket version of the Game Boy was selected as it has a nice flat back that made it easy to attach a solar panel, and in fact the panel sourced for this mod is so well dimensioned, it almost looks like the device came that way.

In the video below, you can see the modification starts by cutting away a large section of the Game Boy’s rear panel to fit the 1000 mAh LiPo battery. The solar panel is then affixed over the back with super glue. A diode is soldered onto the solar cell, and then wired into a charge controller that came with USB-C input. The placement of the charge controller ended up being trickier than expected, but with a little hot glue, it works just fine. Overall this is a simple mod but a brilliant idea.

This isn’t the first solar-powered handheld game system we’ve seen, but it’s nice to see the idea revisited and expanded on, particularly regarding ergonomics. In addition, we love the incredible detail of narration that’s given as this hack slowly takes shape. Video after the break.

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Revolving Plant Tower Is Solar-Powered

July 12, 2021 by Kristina Panos 16 Comments

Do you live in a small or yard-less space, but want to grow things anyway? You’re not totally out of luck — you’ll just have to get creative and probably vertical with your planting scheme. And since apartments and other smallish dwellings often have a limited amount of exposure, it would really help a lot if you could somehow rotate the plants so that they receive even sunlight.

[JT_Makes_It]’s rotating strawberry tower ticks all these boxes and more. The 12 V solar cell powers a small DC motor that spins at the gentle speed of 0.6 RPM. The tube is hanging from a swiveling carabiner that acts like a clutch — if a strong wind comes along or something bumps into it, the motor will continue to spin the carabiner.

[JT_Makes_It] already had a tube with holes, though they did cut several more into it. As built, this is not exactly apartment dweller-friendly, unless you have off-site access to things like plasma cutters and welding equipment. But as they point out, you could theoretically use PVC and a hole saw and make it shorter and therefore lighter. We think this looks great, although we’re a bit concerned about the weight. Not so much on the mechanism itself; that looks strong. We’re just wondering how long that carport frame will support it. Judge the build quality for yourself from the video after the break.

Did you know that strawberries can do tricks? Fasciation makes fanned-out berries, and vivipary makes them hairy.

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Electric RC Plane Flies For Almost 11 Hours

June 27, 2021 by Danie Conradie 45 Comments

Electric RC aircraft are not known for long flight times, with multirotors usually doing 20-45 minutes, while most fixed wings will struggle to get past two hours. [Matthew Heiskell] blew these numbers out of the water with a 10 hour 45 minute flight with an RC plane on battery power. Condensed video after the break.

Flight stats right before touchdown. Flight time in minutes on the left, and miles travelled second from the top on the right.

The secret? An efficient aircraft, a well tuned autopilot and a massive battery. [Matthew] built a custom 4S 50 Ah li-ion battery pack from LG 21700 cells, with a weight of 2.85 kg (6.3 lbs). The airframe is a Phoenix 2400 motor glider, with a 2.4 m wingspan, powered by a 600 Kv brushless motor turning a 12 x 12 propeller. The 30 A ESC’s low voltage cutoff was disabled to ensure every bit of juice from the battery was available.

To improve efficiency and eliminate the need to maintain manual control for the marathon flight, a GPS and Matek 405 Wing flight controller running ArduPilot was added. ArduPilot is far from plug and play, so [Matthew] would have had to spend a lot of timing tuning and testing parameters for maximum flight efficiency. We are really curious to see if it’s possible to push the flight time even further by improving aerodynamics around the protruding battery, adding a pitot tube sensor to hold the perfect airspeed speed on the lift-drag curve, and possibly making use of thermals with ArduPilot’s new soaring feature.

A few of you are probably thinking, “Solar panels!”, and so did Matthew. He has another set of wings covered in them that he used to do a seven-hour flight. While it should theoretically increase flight time, he found that there were a number of significant disadvantages. Besides the added weight, electrical complexity and weather dependence, the solar cells are difficult to integrate into the wings without reducing aerodynamic efficiency. Taking into account what we’ve already seen of [rcflightest]’s various experiments/struggles with solar planes, we are starting to wonder if it’s really worth the trouble. Continue reading “Electric RC Plane Flies For Almost 11 Hours” →