Michael Ciuffo built this neat soil moisture sensor for his girlfriend, since she’s had some bad luck with plants. He writes:
In the June 2012 issue of Nuts & Volts, they did a spread about making a soil moisture sensor with an iPhone interface:
And when I heard my girlfriend say that she has trouble remembering to water her plants, I put two and two together.
Most of the N&V article discussed the code required to interface with the iPhone, but the important part for me was that their soil moisture sensor was nothing more than a simple conductivity sensor. The more water in the soil, the lower its resistance.
Such a sensor doesn’t measure soil moisture in any kind of universal unit, but for a single sensor in a particular soil sample, the measured conductivity is repeatable and proportional to the moisture level. I call these conductivity units “AMU”s or “Arbitrary Moisture Units”.
Neat project and nice build!
Have an amazing project to share? Join the SHOW-AND-TELL every Wednesday night at 7:30pm ET on Google+ Hangouts.
Join us every Wednesday night at 8pm ET for Ask an Engineer!
Learn resistor values with Mho’s Resistance or get the best electronics calculator for engineers “Circuit Playground” – Adafruit’s Apps!
Maker Business — “Finally — some data on whether crowdfunding is a good investment or not”
Wearables — Sample code is your new best friend
Electronics — Meaningful gains
No comments yet.
Sorry, the comment form is closed at this time.