Has anyone had any experience in building soil moisture sensors (for plant pots)? Been checking around on the 'net and found some pro models, but the price is way too steep. Is there any budget DIY solution instead?
hi
the cheap way is to just build a "voltage divider".. five cent solution. Put two probes in the soil.. the probes form one of the resistors in the divider. Do a little googling and you will see how it's done.
For something more accurate, try one of the many schematics around. I found this moisture sensor in ten seconds... do a google image search for moisture & schematic. Here's another. A decent moisture sensor will use an op-amp to conditon the input, and to provide a high-impedance input.
D
Hm, I totally fail at Googling 101.
Thanks for the help!
You might also want to check out Parallax's Stamps in Education site (www.parallax.com) and look for their Earth Measurements text (available online as a pdf). It provides some examples and detail on how they work--pretty easy to convert code examples to the arduino.