'POT' issues with long cable

[Archangel]

Hi ardhuru,
All that stuff you mentioned in Post 1 sounds pretty expensive, and Al's SS Rods do too. So using Al's Idea a little differently, suspend 4 copper stiff wires or rods vertically at different lengths, which you can adjust easily to fit your needs. You can Solder the resistors or Potentiometers to those wires, and install a PIC circuit there, powered by a couple of solar cells easily removed from 2 cheapie Yard Lights, and yes use the nicads that come in those too, then send some form of slow serial data using relatively inexpensive wire, TV lead in, sprinkler wire, twisted doorbell wire . . . to another PIC . Compared to shielded wire and fancy Stainless steel rods this should be cheap. You could put the wire array in a piece of plastic pipe and insert it vertically into the Well, sump, or whatever it is you are checking.

[ardhuru]

Hi ardhuru,
All that stuff you mentioned in Post 1 sounds pretty expensive, and Al's SS Rods do too.

Actually, its not. I just use 10 0.1 uf capacitors strung (stringed?) together in series. A bit of labour involved, but the material cost is nothing.

Hi ardhuru,
and install a PIC circuit there, powered by a couple of solar cells easily removed from 2 cheapie Yard Lights, and yes use the nicads that come in those too, then send some form of slow serial data using relatively inexpensive wire, TV lead in, sprinkler wire, twisted doorbell wire . . .

I was also toying with the separate-pic-for-the sensor idea. In fact, I thought I would use Melanie's trick of data-over-power from an earlier thread to be able to do this over just 2 wires. Wasnt sure how reliable the serial comms would be with my already laid twisted, non-shielded cable.

Will give this a try.