EIM Lab-OnThe-Go Manual page 34

LOTG Lab-On-The-Go Manual
Schematic
Working Principle
A soil moisture detector circuit utilizes the phenomenon that the soil
moisture is inversely related to resistance. Placing two wires into the soil
is electrically equivalent to a variable resistor, which we may use it to
control the base voltage of an N-type transistor configured into an emitter
follower configuration.
Circuiting Setup
32