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.