Battery-Powered Watering Timer Converted to Solar on the Cheap

Watering the garden or the lawn is one of those springtime chores that is way more appealing early in the season than later. As the growing season grinds along, a chore that seemed life-giving and satisfying becomes, well, just another chore, and plants often suffer for it.

Automating the watering task can be as simple as buying a little electronic timer valve that turns on the flow at the appointed times. [A1ronzo] converted his water hose timer to solar power. Most such timers are very similar, with a solenoid-operated pilot valve in line with the water supply and an electronic timer of some sort. The whole thing is quite capable of running on a pair of AA batteries, but rather than wasting money on new batteries several times a season, he slipped a LiPo pack and a charge controller into the battery case slot and connected a small solar panel to the top of the controller.

The LiPo is a nominal 3.7-volt pack, so he did a little testing to make sure the timer would be OK with the higher voltage. The solar panel sits on top of the case, and the whole thing should last for years. And bonus points for never having to replace a timer that you put away at the end of the season with batteries still in it, only to have them leak. Ask us how we know.

Like the best of hacks, this one is quick, easy and cheap — $15 in parts, aside from the timer. There are more complicated irrigation solutions, of course, one of which even won the Hackaday Prize once upon a time. But this one has us ordering parts to build our own right now.

Get Your Name on the Hottest List in the Solar System

How often does NASA name a spacecraft after a living person? How often do you get to launch your name into a star? How often does NASA send probes to explore the sun? If your answer to all these questions is NEVER, then you win the honor of adding your name to an SD card bound for the center of our solar system. We’re already on the list with [William Shatner] so we’ll see you there. Submissions for the hot list aboard the Parker Solar Probe close on April 27th, 2018 and it launches in May.

The Parker Solar probe honors living astrophysicist [Eugene Parker] who theorized a great deal about how the sun, and other stars, emit energy. His work has rightly earned him the honor of seeing his name on a sun-bound probe. We even owe the term, “solar wind” to [Parker].

To draw more attention, you can have a few bits aboard this probe dedicated to you or someone you care about by adding your name to their list. Or you can send the name of your greatest enemy into the hottest furnace for millions of miles. Your call.

Even though our sun is the most prominent heavenly body, NASA hasn’t sent a probe to explore it before. They are good about sharing their models and they really know how to write standards for workmanship.

Continue reading “Get Your Name on the Hottest List in the Solar System”

Rechargeable Robot Mows Lawns

Perhaps one day our robot overlords will look back on all of the trivial things that humans made them do and take retribution on us. Until then, though, there’s no problem having them perform all of our chores. [v.loschiavo] is also exploiting our future rulers and built a robot that mows his lawn automatically as his entry into the 2018 Hackaday Prize.

The robot uses a rechargeable battery system to drive a nylon blade for grass cutting. It also has an obstacle detection and avoidance system that allows it to find the borders of your yard and keep from getting stuck against shrubs and flower beds. And don’t worry about safety, either. There’s a built-in system of sensors that prevents any injuries from occurring. The robot also has a 10 Watt solar panel on the top that helps recharge the battery, but it can also recharge at a base station similar to a Roomba.

The whole robot was 3D printed with the exception of some parts like the cutting motor, solar panel, and gear motors. While nothing except for the pictures and a general overview of the robot has been posted to the project page yet, we hope [v.loschiavo] updates the project with the G-code files, code, and schematics so we can build our own.

Is That A Mars Habitat? A Submarine? A Spaceship? Nope: It’s Home.

[Jan Körbes], an architect living with his daughter in Berlin, specializes in recycling materials. Inspired by discarded grain silos he saw across the Netherlands, he converted one into a micro-home that you would almost expect to see on the surface of mars. The guided tour in the video below give a pretty good feel for the space station feel of the abode.

A lot of the silo house’s design was inspired by [Körbes’] childhood of growing up on boats. It’s exceptionally functional and nearly every nook and cranny of the home can be altered, repurposed, and changed back. For instance: the two pantries on the main floor used to the toilet and shower, but since the silo home is currently set up at ZK/U — Center for Arts and Urbanistics in Berlin — they make use of the facilities there instead.

True to his specialization of creative recycling , a lot of the materials for the house were either donated, or bought at a steep discount due to various reasons. For instance, the windows were a small, unpopular size for most houses but work well here. This led to an evolving design of the house as it was being built, but everything [Körbes] and his daughter need is present inside of fourteen square metres on three floors.

Under the floor on the main level is a bathtub with infrared heating — the cover doubling as the dining table with feet dangling into the tub underneath. The kitchen has a small oven, an old camp stove, and fridge — enough for two people — and the sink uses a foot-activated button so the [Körbes’] use only as much water as they need. A nearby small wood stove with an extendable wood storage basket heats the space.

The house’s electrical (including a solar battery) and water systems are tucked into the basement beside the books, keeping the heavier objects low in such a tall and narrow dwelling. Larger rainwater collection tanks (a hack we’re quite fond of) surrounding the silo house also add ballast in case of storm.

With a two metre ceiling height on the main floor and nearly as much in the bunking quarters upstairs — accessed by a climbing wall, [Körbes] says the space feels much larger than you would expect. Large enough, at least, to host a standing record of a 38-person party. It’s fun to see the ingenuity that goes into tiny living space design. If you missed it, check out these CNC plywood designs for building homes.

Continue reading “Is That A Mars Habitat? A Submarine? A Spaceship? Nope: It’s Home.”

Solar Power In A Can!

When spending time camping, people often bring lanterns, flashlights, and the like — you might even bring along a solar charger. Instructables user [bennelson] is combining all your electrical powered needs by cramming solar power into a can.

Already designed to resist the elements, [bennelson] is using a 50cal. ammo can for a portable enclosure. Inside, he’s siliconed a 15AH, 12V lead-acid battery in the centre to maintain balance and to leave room for the wiring and storage. One cardboard mockup later, he laser-cut the top panel from 1/8″ plywood and secured a 20A solar charge controller, a four-in-one socket panel, and two banana plugs on its top face.

[bennelson] is using 12 AWG wire to match the 20A rating of the solar charge controller — including a fuse for safety — and lever lock-nut connectors to resolve some wiring complications. Industrial velcro keeps the top panel in place and easily removed should the need arise. When he’s out camping, he uses an 18V, 1A solar panel to charge, but can still use a DC power adapter to charge from the grid. Check out the full build video after the break!

Continue reading “Solar Power In A Can!”

Imaging The Neighborhood with Solar Panels

Like many people who have a solar power setup at home, [Jeroen Boeye] was curious to see just how much energy his panels were putting out. But unlike most people, it just so happens that he’s a data scientist with a deep passion for programming and a flair for visualizations. In his latest blog post, [Jeroen] details how his efforts to explain some anomalous data ended with the discovery that his solar array was effectively acting as an extremely low-resolution camera.

It all started when he noticed that in some months, the energy produced by his panels was not following the expected curve. Generally speaking, the energy output of stationary solar panels should follow a clear bell curve: increasing output until the sun is in the ideal position, and then decreasing output as the sun moves away. Naturally cloud cover can impact this, but cloud cover should come and go, not show up repeatedly in the data.

Expected versus actual power output.

[Jeroen] eventually came to realize that the dips in power generation were due to two large trees in his yard. This gave him the idea of seeing if he could turn his solar panels into a rudimentary camera. In theory, if he compared the actual versus expected output of his panels at any given time, the results could be used as “pixels” in an image.

He started by creating a model of the ideal energy output of his panels throughout the year, taking into account not only obvious variables such as the changing elevation of the sun, but also energy losses through atmospheric dispersion. This model was then compared with the actual power output of his solar panels, and periods of low efficiency were plotted as darker dots to represent an obstruction. Finally, the plotted data was placed over a panoramic image taken from the perspective of the solar panels. Sure enough, the periods of low panel efficiency lined up with the trees and buildings that are in view of the panels.

We’ve seen plenty of solar hacks, but this one has to be something of a first. Usually people are more worried about maximizing efficiency or tracking the sun with them.

Making Solar Cells

We will admit that it is unlikely you have enough gear in your basement to make a solar cell using these steps. However, it is interesting to see how a bare silicon wafer becomes a solar cell. If you’ve seen ICs going through fabrication, you’ll see a lot of similarities, but there are some differences.

The process calls for a silicon wafer, some ovens, spin coaters, photolithography equipment, and a dice saw, among other things. Oh, you probably also need a clean room. Maybe you should just buy your solar cells off the shelf, but it is still interesting to see how they are made.

Modern solar cells have some extra structures to improve their efficiency, but the cells in this video are pretty garden-variety. For example, some experimental cells use multiple layers of active devices, each tuned to absorb a different wavelength of light.

If you really want to make your own, there’s another process where you can start with some copper and wind up with a kind of solar cell that uses a copper-based semiconductor material. But don’t be fooled into thinking that making the silicon variety is totally out of reach to hackers, we’ve seen [Sam Zeloof] pull it off.

Continue reading “Making Solar Cells”