Hacking a Capacitive Soil Moisture Sensor for Frequency Output

A project log for The Cave Pearl Project

Creating a generic underwater data logging platform that is easy to build & modify for many different environmental monitoring projects.

Edward MallonEdward Mallon 10/28/2020 at 17:490 Comments

Ok, right up front I'll admit that combining an $1 ADS1115 board with these cheap soil moisture probes is already a decent soil moisture solution for most projects. So I was just messing around here to see what I'd get:

Pin powering the low-power TLC555 worked well, but at the low-ish output frequencies I was using it's really only good as a water level sensor because the probe polarizes over time in soil. But I'm sure I'll find a problem for this solution sooner or later  :-)