Process

In order to successfully implement my design, there were a few challenges.  The biggest challenge was in sound detection.  Using the SparkFun Sound Detector was my first choice, since it is able to detect the full sound wave.  While this may have allowed for more functionality in my product, it was a little bit too advanced for my application.  Really, I just needed to detect if sound was present.  This led me to use and Electret Sound Detector, which is an On/Off detector, switching on when the sound elevates past a threshold.

I also decided to use a DIY moisture analyzer.  This type of device was easy to construct:  2 metal screws, a wire attached to each via a heat-shrink wrap, and a spacer to keep the "leads" at a constant distance.  The wiring for this sensor is then similar to most of the other resistive sensors.  However, the sensitivity of this type of sensor is not very good.  The range of detection between "dry" and "moist" is not very great, creating some problems when fine-tuning the code to work properly.