It does it's job, allowing everything to play nice together. Also gives the ability to code in button control for station selection, maybe add an RTC and have a radio alarm. Project + (Arduino + Imagination) = Endless possibilities.
If it were my project I would use 2 or more piezos. At least one for soft taps and one for hard taps. Each with its own conditioning circuit for it's range. Taking the example from Taiko Trainer (LM358) link I posted above, I would go from there. I have quite a few different piezos hanging around and have been able to get a nice pulse on a few that I tried using variants of those circuits. Also, I would test the conditioning circuit while someone is dancing and make adjustments according to those readings. Are you using a breadboard for the conditioning circuit? Cleaner readings from PCB board. Are you using a plain flat disk piezo? If so what size?
Samples of what? How are you determining the moisture content prior to drying? Example: A saturated sponge weighs 10 oz. . Say it's weight is a combination of 8oz water and 2oz sponge material. So when it has 50% of it's moisture content removed it will weigh 6 oz. .
/* # Example code for the moisture sensor # Editor : Lauren # Date : 13.01.2012 # Version : 1.0 # Connect the sensor analog out to the A0(Analog 0) pin on the Arduino board # Connect the sensor VCC pin to 5v pin on Arduino the board # Connect the sensor GND pin to GND pin on the Arduino board. # the sensor value description # 0 ~300 dry soil # 300~700 humid soil # 700~950 in water */