I am looking for helps here.
Any feedbacks or suggestions would be so helpful and great since I am not really familiar with using Arduino and sensing system.
I am working on a prototype for a sound installation.
I've got 6 of 4' by 4' wooden platforms that underneath of each platform has 4 piezo transducer sensors and one contact mic.
the contact mic is for MOTU inputs, and other 4 piezo sensors (https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1956776_-1
) that wired to Mux shield (http://www.sparkfun.com/products/9832
) as 24 analog inputs. I refer to the Arduino circuit diagram called "Knock "(http://www.arduino.cc/en/Tutorial/Knock
) basically 1M ohm for each inputs. Also, I am using Mux Shield Anlog Input sketch for reading sensors. (http://mayhewlabs.com/code/Mux_Shield_AnalogIn_Example.pde
So on my breadboard, there are 24 piezos x 1M ohms and connect to analog inputs(mux 0 and mux 1) and all shared the same ground.
Then, I have faced two problems.
1) When I only worked with Arduino(only 6 analog inputs) without Mux shield, i get some values when i knock the platform; however, when i use Mux shields (more piezos are hooked up), the values are very small range to use. For example, Mux0 the first 4 inputs worked, but nothing else, everything else says 0.
2) I have heard that piezo wire voltages could drop out if the wire is 16ft long, so I try to use Operational Amplifier,
but it doesn't seem to work at all with Mux Shield.
So I don't know where to start debugging this.
I am happy to think about Arudino Mega, If this could be the best solutions. But again, not sure whether that will be the best solutions,
and I have to reduce inputs.
Thank you for reading this long concerns. I looked through the forums on Piezo pre Amplifier circuit, but not sure how I can even start.
Partially, I think i don't understand the mechanism enough.
I really appreciate your inputs. Once again, thank you so much.