I have been playing around with this microphone. Mostly all I have done is power it with 3.3v and look at the outputs with an oscilloscope.
I read that the potentiometer that adjusts the sensitivity is only supposed to set the level at which the digital output goes high. However, I noticed that this adjustment also changes the offset of the analog output. If I set it so that the "sound detected" LED goes out, the analog output is sitting at around 1.7v even in a relatively quiet room.
I guess this is normal?
Yup, that's the one.
Yes.
The pot adjusts the pull up current of the electret microphone, and therefore the bias voltage of the analogue output and threshold voltage of the comparator.
Don't expect a lot from this device.
It has no pre-amp, so it only works with relatively loud sounds.
Leo..
1 Like
Oh, interesting.
I just managed to find a schematic that claims to be of the module. I think I found this before but wasn't sure it was accurate. Based on what you said the pot is doing, it seems like it is accurate.
Can you suggest a better microphone module?
I'm trying to build a sensor that detects when my home alarm is going off. So, finesse is not required. It'll be either a baseline noise level or freaking loud, because the alarm is shockingly loud lol.
Having said this, I wouldn't mind having a microphone module that I can use to detect noise or conversation in a room. I'd like to experiment with turning on things when someone enters a room.
Adafruit and Sparkfun have much better quality, amplified microphone modules.
Nice. Wanna suggest a few of your favorites? 
So, googling that will get me @jremington 's favorite microphone modules? Who would've thunk it 
1 Like