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soil moisture sensor

davenn

Moderator
ohhh gosh a damp detector was my first serious electronic project some 40 years ago (showing my age) it was for detecting dampness on walls of buildings.

in practice it would work for your need as well so long ago I cant remember much about it.
for your use you need a couple of ... preferably stainless steel spikes ( so they wont rust) say 8 - 12 cm long and mounted ~ 3cm apart. That will do for the probes

have you googled soil moisture sensor circuits ?? probably a good place to start :)

Dave
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Another option is to have a spike that is insulated to almost the end and a sleeve over that so that only a single probe is required.

An alternative is a plastic tube with a number of conductive bands around it, however that really only works well in liquids (and thus obviously not for detecting moisture).
 
It's a simple circuit.
Start looking for circuits using a 4011 CMOS IC. I saw somebody make one using 4011's also.
 
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