This moisture meter was based on a circuit from Forrest Mim’s excellent “Getting Started in Electronics” book. It uses an Ampere meter (not pictured) via a amplifying transistor to display the conductivity of the soil in a planter. And it works! This setup may be the basis for our primary plant sensors for ITPlant.
please show the circuit diagram of moisture meter and the main device used on it. Thank you
The circuit is shown in this posting.