I want an analog sound sensor so I can approximate the noise level in a room, then have the arduino do things depending on the level. I've seen cheap digital ones, but want the granularity of an analog input. Those digital ones also often have an analog pin, but it's hooked up directly to the mic and will give a sine wave output centered at +/- 0V. The amplitude may be quite low, and would requires rapid sampling and some math to get a good idea of the noise level. Depending how negative the signal is, it could also be harmful for the arduino. There is a wiring diagram of the crappy sensors here. I have soldering tools and will need to use a protoboard or something for the rest of the project anyway, but a pre-fabricated module is probably the easier and cheaper option.
Need a sensor that does the following:
-60-90dB range with 10+ measurable noise levels within that range
-Powered by 3.3V, 5V, or 12V
-Won't exceed 0V-5V output long enough to damage an arduino's input pins
-Output is a measure of sound level, not the actual sound wave (ie take the positive half of the wave)
-Available on ebay
And ideally:
-Output changes slowly and is like an average noise level (instantaneous drops in music don't result in sudden output drops)
-Under $5 USD (or equivalent) before shipping
I don't know enough electrical stuff to know what components need to be on the module to get what I want. I also don't often see the output of a sensor module, so I can't figure out if it's suitable.
What should I get?