This variable resistor is connected in a voltage divider configuration, and Arduino collects a voltage proportional to resistance between the 2 wires. Insert the 2 probes (wires, pcb) in the dry soil ...

The soil moisture sensor module , built around the LM393 comparator, gives an active-low (L) level output when the soil is dry (determined by a pre-setted threshold value). This digital output (wet ...

My soil-moisture reading was in the low 700s in soil that had around 30 percent moisture (according to a comparison with a commercial soil-moisture sensor), and 661 in a drier pot.

13 thoughts on “ Garden Sensors Measure Soil Moisture And Greenhouse Temperature ” John says: May 14, 2012 at 5:01 pm I would ... Arduino says: August 22, 2014 at 2:44 am ...

As a preview of his latest book, Arduino Project Handbook: 25 Practical Projects to Get You Started, Mark Geddes takes us through the project to create a simple plant monitor. In this project I’ll ...