Hackaday Prize Entry: Water Level Station

All over the world, in particular in underdeveloped countries, people die every year by the thousands because of floods. The sudden rise of water levels often come unannounced and people have no time to react before they are caught in a bad spot. Modern countries commonly have measure equipment deployed around problematic areas but they are usually expensive for third world countries to afford.

[Benne] project devises a low-cost, cloud-connected, water level measuring station to allow remote and central water level monitoring for local authorities. He hopes that by being able to monitor water levels in a more precise and timely fashion, authorities can act sooner to warn potentially affected areas and increase the chance of saving lives in case of a natural disaster.

At the moment, the project is still in an early stage as they are testing with different sensors to figure out which would work best in different scenarios. Latest version consists essentially in an Arduino UNO, an ultrasonic distance sensor, and a DHT temperature/humidity sensor to provide calibration since these characteristics affect the speed of sound. Some years ago, we covered a simple water level monitoring using a Parallax Ping sensor, but back then the IoT and the ‘cloud’ weren’t nearly as fashionable. They also tested with infrared sensors and a rotary encoder.

They made a video of the rotary encoder, which we can see below:

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Electronic float valve keeps the horse’s feet dry

[Bob] built this simple device that can best be described as an electronic float valve. He was wasting a lot of water from overflowing water troughs and buckets around his farm. He would usually put the hose in the container, turn on the water valve and carry on with his work. By the time he remembered to come back, the area would be flooded. It’s obvious that there’s many different ways to solve a problem. For example, a simple mechanical float valve might have worked, but it’s not horse friendly and liable to get damaged soon.

The electronics is unabashedly minimal. An ATtiny85 controls a relay via a common variety NPN transistor. The relay in turn switches the solenoid valve. A push-button tells the microcontroller to start the water flowing, and when the water level gets high enough that it touches two hose clamps, the micro shuts it off again.

There’s some ghetto engineering going on here. The electronics is driven by a 9V battery, although the relay and the solenoid valve that [Bob] used are both rated for 12V. He’s not even using any sort of voltage regulation for the ATtiny, but instead dropping the voltage with a resistor divider. (We wonder about battery life in the long run.)

He built all of it on perf board and stuffed it inside a small enclosure, with two wires coming out for the level sensor and another two for the solenoid, and it seems to work. Check the video below where [Bob] walks through his build.

While some may point out the many short comings in this build, [Bob] found the one solution that works for him. Sometimes the right solution is what you’ve got on hand, and we’re glad he’s hacking away and sharing his work. And check out this wireless water level sensor that he built some time back.

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Sensor Net Makes Life Easier for Rice Farmers

Rice is cultivated all over the world in fields known as rice paddies and it is one of the most maintenance intensive crops to grow. The rice paddy itself requires a large part of that maintenance. It is flooded with water that must be kept at a constant level, just below the height that would keep rice seedlings from growing but high enough to drown any weeds that would compete with the rice stalks for nutrients. This technique is called continuous flooding and a big part of the job of a rice farmer is to inspect the rice paddy every day to make sure the water levels are normal and there are no cracks or holes that could lead to water leakage.

This process is labor intensive, and the technology in use hasn’t changed much over the centuries. Most of the rice farmers in my area are elders with the approximate age of 65-70 years. For these hard working people a little bit of technology can make a big difference in their lives. This is the idea behind TechRice.

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Low water indicator for coffee maker couldn’t be simpler


The coffee maker which [Donald Papp] uses every morning has a water reservoir on the back that can last for several days. This means he forgets to check it and from time to time will return to find that nothing has brewed. He decided to add a low-water indicator to the machine. His approach is about as simple as it gets and we admire that accomplishment.

If it were our project we’d probably try to complicate it in one way or another. The use of a microcontroller and ultrasonic rangefinder (like this tank level indicator from a February links post) would be overkill. No, [Donald] boiled down the electronics to a homemade switch, a blinking LED, and a battery. The switch is a flexible piece of metal attached to a plastic cap using some monofilament. The cap goes in the reservoir and floats until the water gets too low, it then pulls on that metal, completing a circuit between the battery and the LED. That’s it, problem solved.

Now he just needs to plumb the coffee maker into a water line and he’ll really be set.