LoRa Helps With Remote Water Tank Level Sensing

July 7, 2022 by 9 Comments

[Renzo Mischianti]’s friend has to keep a water tank topped up. Problem is, the tank itself is 1.5 km away, so its water level isn’t typically known. There’s no electricity available there either — whichever monitoring solution is to be used, it has to be low-power and self-sufficient. To help with that, [Renzo] is working on a self-contained automation project, with a solar-powered sensor that communicates over LoRa, and a controller that receives the water level readings and powers the water pump when needed.

[Renzo] makes sure to prototype every part using shields and modules before committing to a design, and has already wrote and tested code for both the sensor and the controller, as well as created the PCBs. He’s also making sure to document everything as he goes – in fact, there’s whole seven blog posts on this project, covering the already completed software, PCB and 3D design stages of this project.

These worklogs have plenty of explanations and pictures, and [Renzo] shows a variety of different manufacturing techniques and tricks for beginners along the way. The last blog post on 3D designing and printing the sensor enclosure was recently released, and that likely means we’ll soon see a post about this system being installed and tested!

[Renzo] has been in the “intricately documented worklogs” business for a while. We’ve covered his 3D printed PCB mill and DIY soldermask process before, and recently he was seen adding a web interface to a 3D printer missing one. As for LoRa, there’s plenty of sensors you can build – be it mailbox sensors, burglar alarms, or handheld messengers; and now you have one more project to draw inspiration and knowledge from. [Renzo] has previously done a LoRa tutorial to get you started, and we’ve made one about LoRaWAN!

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Water Your Plants Just Four Times Per Year

May 19, 2022 by 20 Comments

While it’s true that some plants thrive on neglect, many of them do just fine with a few ounces of water once a week, as long as the light level is right. But even that is plenty to remember and actually do in our unprecedented times, so why bother trying? [Martin] has solved this problem for us, having given every aspect of automatic plant care a lot of thought. The result of his efforts is Flaura, a self-watering open-source plant pot, and a YouTube channel to go with it.

The 3D-printed pot can easily be scaled up or down to suit the size of the plant, and contains a water reservoir that holds about 0.7 L of water at the default size. Just pour it in through the little spout, and you’re good for about three months, depending on the plant, the light it’s in, and how much current water it draws. You can track the dryness level in the companion app.

Whenever the capacitive soil moisture sensor hidden in the bottom of the dirt detects drought conditions, it sends a signal through the Wemos LOLIN32 and a MOSFET to a small pump, which sends up water from the reservoir.

The soil is watered uniformly by a small hose riddled with dozens of tiny holes that create little low-pressure water jets. This is definitely our favorite part of the project — not just because it’s cool looking, but also because a lot of these types of builds tend to release the water in the same spot all the time, which is. . . not how we water our plants. Be sure to check out the project overview video after the break.

No printer? No problem — you could always use an old Keurig machine to water a single plant, as long as the pump is still good.

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Sea Level: How Do We Measure Global Ocean Levels And Do Rising Oceans Change That Benchmark?

March 8, 2021 by 34 Comments

Every summer you go down the shore, but lately you’ve begun to notice that the beach seems narrower each time you visit. Is that the sea level rising, or is the sand just being swept away? Speaking of sea levels, you keep hearing that they rise higher every year — but how exactly is that measured? After all, you can’t exactly use a ruler. As it turns out, there are a number of clever systems in place that can accurately measure the global sea level down to less than an inch and a half.

Not only are waves always rippling across the ocean’s surface, but tides periodically roll in and out, making any single instantaneous measurement of sea level hopelessly inaccurate. Even if you plan to take hundreds or thousands of measurements over the course of weeks or months, taking the individual measurements is still difficult. Pick a nice, stable rock in the surf, mark a line on it, and return every hour for two weeks to hold a tape measure up to it. At best you’ll get within six inches on each reading, no matter what you’ll get wet, and at worst the rock will move and you’ll get a damp notebook full of useless numbers. So let’s take a look at how the pros do it.

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The Internet Of Christmas Tree Watering

January 1, 2021 by 5 Comments

There’s nothing quite like a real Christmas tree, but as anyone who’s had one will know there’s also nothing like the quantity of needles that a real tree can shed when it runs short of water. It’s a problem [RK] has tackled, with a Christmas tree water level monitor that has integration with Adafruit’s cloud service to give a handy phone notification when more watering is required.

The real interest in this project lies in the sensor development path. There are multiple ways of water level sensing from floats and switches through resistive and light scattering techniques, but he’s taken the brave step of using a capacitive approach. Water can be used as a dielectric between two parallel metal plates, and the level of the water varies the capacitance. Sadly the water from your tap is also a pretty good conductor, so the first attempt at a capacitive sensor was not effective. This was remedied with a polythene “sock” for each electrode constructed with the help of a heat sealer. The measurement circuit was simply a capacitive divider fed with a square wave, from which an Adafruit Huzzah board could easily derive an amplitude reading that was proportional to the water level. The board then sends its readings to Adafruit.io, from which a message can be sent to a Slack channel with the notification enabled. All in all a very handy solution.

Plant care is a long-running theme in Hackaday projects, but not all of them need a microcontroller.

The Challenges Of Monitoring Water Streams And Surviving Mother Nature

June 30, 2020 by 23 Comments

Small waterways give life in the form of drinking and irrigation water, but can also be very destructive when flooding occurs. In the US, monitoring of these waterways is done by mainly by the USGS, with accurate but expensive monitoring stations. This means that there is a limit to how many monitoring stations can be deployed. In an effort to come up with a more cost-efficient monitoring solution, [Rohan Menon] and [Ian Vernooy] created Aquametric, a simple water level, temperature and conductivity measuring station.

The device is built around a Particle Electron that features a STM32 microcontroller and a 3G modem. An automotive ultrasonic sensors measures water level, a thermistor measures temperature and a pair of parallel aluminum plates are used to measure conductivity. All the data from the prototype is output to a live dashboard. The biggest challenges for the system came with field deployment.

The great outdoors can be rather merciless with our ideas and electronic devices. [Rohan] and [Ian] did some tests with LoRa, but quickly found that the terrain severely limited the effective range. Power was another challenge, first testing with a solar panel and lithium battery. This proved unreliable especially at temperatures near freezing, so they decided to use 18 AA batteries instead and optimized power usage.

The mounting system is still an ongoing challenge. A metal pole driven into the riverbed at a wider part ended up bent (probably from ice sheets) and covered in debris to the point that it affected water level readings. They then moved to a narrower and shallower section in the hopes of avoiding debris, but the rocky bottom prevented them from effectively driving in a pole. So the mounted the pole on a steel plate which was then packet with rock to keep it in place. This too failed when it tipped over from rising water levels, submerging the entire sensor unit. Surprisingly it survived with only a little moisture getting inside.

For the 2020 Hackaday Prize, Field Ready and Conservation X Labs have issued challenges that need require some careful consideration and testing to build things that can survive the real world. So go forth and hack!

The HackadayPrize2020 is Sponsored by:
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Water Flow Meter Knows Tank Level

November 11, 2019 by 27 Comments

There’s almost always more than one way to get any particular job done. Suppose for instance you have a tank you fill up from a well, and you’d like to know when the time is right to refill the tank. The obvious answer is to measure the level of the tank, and there are plenty of ways to do that. However, [Liam Hanninen] has a different approach. Using a flow meter, he measures how much water leaves the tank. Assuming that you know it was once full, you can deduce how much water is left.

Using a YF-S201 flowmeter on a Raspberry Pi, the code uses Python to populate a database. The meter will need to be calibrated to get an exact volume measurement.

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Steampunk Water Thief Clock Steals Attention, Too

November 8, 2019 by 7 Comments

The funny thing about clocks is that the more intriguing they are to look at, the more precious time is wasted. This steampunk clepsydra is no exception. A clepsydra, or water thief clock is an ancient design that takes many forms. Any clock that uses the inflow or outflow of water to measure time could be considered a clepsydra, even if it uses electronics like this steampunk version.

[DickB1]’s sticky-fingered timepiece works by siphoning water from the lower chamber into the upper chamber on a one-minute cycle. An MSP430 and a MOSFET control the 12 V diaphragm pump. As the water level rises in the upper chamber, a float in the siphon pushes a lever that moves a ratchet and pawl that’s connected to the minute hand. The hour hand is driven by gears. A hidden magnet and Hall effect sensor help keep the clock clicking at one-minute intervals.

Although [DickB1] doesn’t tell you exactly how to replicate this clock, he offers enough information to get started in designing your own. Take a second to check it out after the break.

Most of the thieving around here is done for the joules, so here’s a joule thief running a clock.

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