I am trying to get the Adafruit Electret Microphone Amplifier to work with an ATTiny85 but am having some trouble with the reference voltage. I am using a 5V circuit because I am also powering a strip of LEDs and I am trying to avoid making the circuit too complicated with a bunch of extra regulators. Since the chip should use the supply voltage as reference by default I figured I would be fine in using 5V across the board. But I get basically no response out of the mic when doing this. However, if I hook up 5V to AREF and then call analogReference(EXTERNAL), everything works fine.
Any thoughts as to why this would be the case? This completely goes against my understanding (and experience) of the default AREF on the ATMega chips.
It would be nice to be able to use that AREF pin for something else :)
Side Note: I am going to be powering this with batteries so maybe I just need it anyways? But again, I thought the default mode was to use VCC as the reference...