Hi,
I searched both with google and here in the forum but haven’t found a solution yet. Hopefully you can help?
My arduino is installed in a garden hut and shall activate a pump when water level in a tank that is approx 20m away reaches a certain level. I got hardware and software working fine in a test setup with short wires but when I connect the long cable (twin wires, copper ends hanging in the tank to short the circuit when both ends are in water) I assume there is too much resistance in the wires to make Arduino recognise when water shorts the circuit.
Any ideas how I can get this to work is very, very appreciated!
Are you using digitalRead() to detect the short circuit between the wires ? If so, then consider using analogRead() instead and set the threshold appropriately
However, the bare wires are likely to corrode quite quickly whatever method you use
A float would be the simplest way. Since you already have conductive probes, take a look at the liquid level sensor project at the bottom of this page: Thermometer simulator | theselittlemachines
Sorry, I don't have page anchors set up or I'd provide a link straight to the right point.
It's tuned to detect syrup. You can adjust the settings in the code for water conductivity, it's a simple change.
If I measure common tap water with two standard VOM probes with probes about an inch apart I get about 500 Meg Ohms. Sixty meters is about 200 feet. AWG 18 copper wire has a resistance of about 6.5 Ohms per 1,000 feet or 60.9 meters. I do not see where the added resistance of the wire should matter much. What gauge wire are you using? You are sure your connections are clean and tight? I just doubt your wire length is a problem. Can you please post a schematic of your circuit.
