first of all, Im from Cuba, that means I may have some problems to find parts...
I have a little system to measure the water level in my house water tank. The system is pretty rough: a proximity sensor HC-SR04 well fixed in the top of the tank, some long wires to an ArduinoNano, and a LCD screen where I display information as: water level in liters and in %.
The problem is the proximity sensor HC-SR04 seems to be broken now, not work at all and I was thinking in replace it by raw cables
So... My questions are:
-Is this posible? I just test it with a glass of water and two short wires and it work, but sometimes it throw me some falses-positives... It may be my code: just light on a led if digitalpin X is high when I put two wires in the water (1 wire to arduino 5V pin and the other to the digitalpin I wanna check if is high), and it do it, but when I pull out the wires the led stay on for more than a few seconds.
-If it is posible, how long can be the wire? Is 10m ok?