Here is a tested Arduino project that uses 3 sensor probes as water level indicator with 3 leds and one LCD display + a simple controller that turns on a motor when the water has reached the desired ...

And the third, tells it what type of trigger to look for, a logic high, a logic low or a transition between the two. You can find detailed articles/tutorials on Arduino Interrupts (prepared by me) ...

I've just come across a no-name non-contact, high-precision 80 GHz mmWave radar sensor for liquid level detection with a 40m ...