Irrigation Controller Uses Google Calendar To Make Things Easy

February 20, 2020 by Lewin Day 18 Comments

Irrigation controllers have been around for a long time, often using similar hardware inside that would be familiar to the average maker. However, many of the products on the shelf at your local hardware store can be quite expensive for what amounts to a microcontroller, display, and relay board. [oscillatory] had such a rig, but wanted to bring it into the 21st century, IOT style.

The existing Holman irrigation system consisted of a control box, hooked up to four solenoid valves controlled by relays. [oscillatory] decided that replacing this with something fancier would thus be straightforward. A relay board packing an ESP8266 was sourced, and flashed with the Tasmota firmware. This was then hooked up to run off the Holman’s 24 VAC supply via a CCTV power supply, allowing the new controller to be run in parallel with the existing hardware, just in case. Scheduling is then controlled by Google Calendar, in concert with Home Assistant.

[oscillatory] now has a watering system that can be controlled over the web, and without the need to install any custom apps. Simply creating a calendar entry is enough for the system to spring into action. We’ve seen others use a similar approach, too. It’s a great example of using off-the-shelf parts to whip up a useful custom home automation setup!

Detecting Water Before It’s Too Late

November 14, 2019 by Gerrit Coetzee 25 Comments

[mcu_nerd] is like any engineer, which is why his problem of an occasionally leaky water heater sure looks like a research project with no end in sight. Sure there’s probably a commercial product out there that can be had for half the cost and a few clicks of the mouse, but what’s the point in actually solving the problem?

His log starts with research into detecting low battery voltages. Then it was a quick exploration in designing low-power circuits. When the Flexible PCB contest came along, he realized that there was a chance to design a better electrode, and he ended up winning one of the vouchers; which is where he’s at now.

It’s definitely a work in progress, and if anything it’s just a quick five minute read and an opportunity to commiserate with another wayward soul. We do like his clever use of a tealite candle tin as both the second electrode and case for his water detection circuit. There are also some KiCad files and code.

Clean Water Technologies Hack Chat

September 3, 2019 by Dan Maloney 2 Comments

Join us on Wednesday, September 4th at noon Pacific for the Clean Water Technologies Hack Chat with Ryan Beltrán!

Access to clean water is something that’s all too easy to take for granted. When the tap is turned, delivering water that won’t sicken or kill you when you drink it, we generally stop worrying. But for millions around the world, getting clean water is a daily struggle, with disease and death often being the penalty for drinking from a compromised source. Thankfully, a wide range of water technologies is available to help secure access to clean water. Most are expensive, though, especially at the scale needed to supply even a small village.

Seeing a need to think smaller, Ryan started MakeWater.org, a non-profit program that seeks to give anyone the power to make clean water through electrocoagulation, or the use of electric charge to precipitate contaminants from water. There’s more to MakeWater than electrocoagulation kits, though. By partnering with STEM students and their teachers, MakeWater seeks to crowdsource improvements to the technology, incorporating student design changes into the next version of the kit. They also hope to inspire students to develop the skills they need to tackle real-world problems and make a difference in the lives of millions.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, September 4 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Graphene Desalinates Sea Water

March 8, 2019 by Al Williams 36 Comments

Even though the majority of the Earth is covered in water, a surprising number of people around the world don’t have easy access to clean drinking water. The oceans of course are full of salt, and it is difficult to filter that salt out. Researchers at the University of Manchester have found a way to improve a graphene-based filter mechanism that could help convert sea water to potable water.

Pure graphene can do the job, but it is difficult to manufacture in commercial quantities. In addition, the membrane requires the creation of tiny holes, further complicating the production. The new method uses graphene oxide, which is very simple to make and deploy.

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Create An Aurora Of Your Own

February 2, 2019 by Bryan Cockfield 14 Comments

Throughout our day-to-day experiences, we come across or make use of many scientific principles which we might not be aware of, even if we immediately recognize them when they’re described. One such curiosity is that of caustics, which refers not only to corrosive substances, but can also refer to a behavior of light that can be observed when it passes through transparent objects. Holding up a glass to a light source will produce the effect, for example, and while this is certainly interesting, there are also ways of manipulating these patterns using lasers, which makes an aurora-like effect.

The first part of this project is finding a light source. LEDs proved to be too broad for good resolution, so [Neuromodulator] pulled the lasers out of some DVD drives for point sources. From there, the surface of the water he was using to generate the caustic patterns needed to be agitated, as the patterns don’t form when passing through a smooth surface. For this he used a small speaker and driver circuit which allows precise control of the ripples on the water.

The final part of the project was fixing the lasers to a special lens scavenged from a projector, and hooking everything up to the driver circuit for the lasers. From there, the caustic patterns can be produced and controlled, although [Neuromodulator] notes that the effects that this device has on film are quite different from the way the human eye and brain perceive them in real life. If you’re fascinated by the effect, even through the lens of the camera, there are other light-based art installations that might catch your eye as well.

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Artistic Images Made With Water Lens

December 7, 2018 by Bryan Cockfield 15 Comments

It’s said that beauty and art can be found anywhere, as long as you look for it. The latest art project from [dmitry] both looks in unassuming places for that beauty, and projects what it sees for everyone to view. Like most of his projects, it’s able to produce its artwork in a very unconventional way. This particular project uses water as a lens, and by heating and cooling the water it produces a changing image.

The art installation uses a Peltier cooler to periodically freeze the water that’s being used as a lens. When light is projected through the frozen water onto a screen, the heat from the light melts the water and changes the projected image. The machine uses an Arduino and a Raspberry Pi in order to control the Peliter cooler and move the lens on top of the cooler to be frozen. Once frozen, it’s moved again into the path of the light in order to show an image through the lens.

[dmitry] intended the project to be a take on the cyclical nature of a substance from one state to another, and this is a very creative and interesting way of going about it. Of course, [dmitry]’s work always exhibits the same high build quality and interesting perspective, like his recent project which created music from the core samples of the deepest hole ever drilled.

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inside shot of a refrigerator with water bulk tank and seltzer pump

Continuous Seltzer Deployment System Solves Our Bubbly-Water Sourcing Problems

October 1, 2018 by Brian Boucheron 19 Comments

Seltzer water – that bubbly, carbonated water that disappoints sugar-craving children everywhere – has experienced a steady rise in popularity over the past few years. This is perhaps partly fueled by the availability of countertop carbonators such as the SodaStream.

Not satisfied with the tedious and pedestrian process of manually carbonating individual bottles of water, [piyoman] has instead built a tidy little tap of unlimited cold, filtered seltzer. It’s no easy gag. The build uses a commercial carbonator pump, reverse osmosis water filter, bulk tank, and a standard CO2 cylinder to create a constant source of carbonated water. Most of this setup is stuffed into a dorm-sized fridge (tetris-style) and topped with a fancy beer faucet to dispense the resulting bubblewater.

At roughly $800 for the documented system, you need to have a great reason to build your own. But [piyoman] provides detailed instructions, a parts list, and suggestions for cost savings and future improvements if you do take on a system like this for your seltzer needs.

Cheaper Carbonation Options

While looking at how DIY carbonation has been done in the past we found [Richard Kinch’s] Carbonating at Home with Improvised Equipment and Soda Fountains page which dives into many other options. His site – a wonderful, dense demonstration of the beauty of “web 1.0” – walks through the basics of carbonated water, discusses CO2 tanks and gauges, and shows how to build a simple carbonation cap for making seltzer in standard PET soda bottles.