Ultrasonic Water Level Sensor

I'm looking into creating a solid state (for the sake of longevity, and to avoid the need for maintenance) device that would detect when a water level has dropped below a certain level, and send a simple shutoff signal to external equipment when this happens. Ultrasonic was chosen because it is solid state, and because unlike a laser, there's no optics to get dirty over time.

Going off of my limited understanding of electronics, it would likely involve an ultrasonic sensor, and something that would A) control the sensor, B) interpret the data from it (so that short-term changes in water level don't trigger the shutoff signal), and C) send the shutoff signal to the external equipment.

Is Arduino the best tool for this? Or could it be done with some readily available (and cheap) IC chip, with little to no tinkering otherwise? Is there something that would require no programming, or is Arduino or something like it the only solution without specially creating a new chip for this specific purpose?

Thanks for the help.

How deep is your tank, adafruit have these devices you could position in the wall of the tank to the desired level you want to detect.
They use light refracting internally around a conical pism, when the media, ie water, on the outside changes to air the refrective index changes and the light refected changes, thus producing a change in output.

I don't know if you could submerge the entire device on a rod so you wouldn't have to put a hole in the tank.

You might need to ask adafruit.

Tom.. :slight_smile:

We were concerned about using any kind of optics, and especially submerging them, as the water in question would have foreign matter, etc, that would eventually the coat any lens, or otherwise make it difficult to accurately detect changes to the water due to the inconsistencies of its color.

However, regardless of the sensor that is eventually decided upon, would an arduino even be the right choice for this? Is there a microcontroller that would do the trick, or even a preprogrammed chip of some sort that we could simply connect to the sensor and call it a day?

Yes, this could be done with an Arduino. An Arduino is a microcontroller. With one input and one output, it sounds like too small a job for anything more powerful like a raspberry pi.

As for pre-programmed chips, I don't know, is not something I have researched. You should definitely do some research.

PS ultrasonic sensors are not solid state. They have moving parts. But you can get waterproof ones.

If you want to produce a product to be sold in quantity, and you really don't want much more than an "on/off" switch, consider an ATtiny (about $3) as the final platform. But you can develop using an ordinary Arduino, for convenience. Or use an ordinary Arduino if you only need a few instances of the device. (A BASIC Arduino, with the USB circuitry for programming it in a "use over and over" cable, is easy enough to buy for... $10? Certainly no more than $20.

"What you need"... What you need to "play" with Arduino- aht0YouNeed.htm

"Getting started with ATtiny"... ATtiny Introduction

If your tank is not conductive, and accessible from the outside, there are level detectors that are solid state (works capacitive). Those have a built-in LED, and a simple on/off output that you can connect to something else. This would be the simplest solution to your problem.
Like these. You should also be able to find them on aliexpress, amazon, e-bay, element14, and others. Just easy to find for me as I bought these before.

or, you could just use a float switch 99 cents on e-bay