eBay booty, standard lack of documentation

I bought this "sensor board" off of eBay, and like most components from eBay it came in an anti-static bag, inside a padded envelope, from China. No documentation, no links to documentation, nothing. http://www.ebay.com/itm/260874068947?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

It has the following pins, and their assumed meanings: AO - analog out? GND - ground VCC - voltage(5v?) DO - digital out?

It has an electret mic, and I guess this is an envelope follower IC(?), has anyone worked with this? Does anyone have a link to documentation for this thing, or should I just setup a digital pin as input, analog pin as input, and fire up the serial terminal?

Based on the limited information in the Ebay listing, and your description of the board (and the pic in the listing), I'd say this is how it works (WAG):

  1. A0 outputs an analog signal value representing the signal intensity
  2. D0 outputs HIGH or LOW, depending on signal intensity
  3. The potentiometer on-board the sensor probably sets a "trigger" level for D0 (but it might somehow affect A0, too)

So - I'd say you'd do well to hook it up, and fire up the terminal, like you posted...