ESP8266 Community Forum

- Sun Aug 09, 2015 12:01 pm #25457 Thank you everyone for the replies! I've recently purchased an NTE928M OP-AMP and am experimenting with that for now. Still haven't gotten to where I want to be yet. I've also been trying to take a crash "Google" course on an OP-AMP as this is the first time I've used them.

For the sensor, the link is: http://www.adafruit.com/products/1063

Thank You all once again! I really appreciate it.

- Sun Aug 09, 2015 12:23 pm #25463 Oh !
But since it is a microphone and that your want to mesure audio level, a AC signal, not a DC signal, removing the VDD/2 offset is much more easier : add a capacitor at the output then a diode to clamp the negative voltage.
Just google a bit, you will find plenty of "audio level" indicator circuit.

- Sun Aug 09, 2015 5:33 pm #25480

For the sensor, the link is: http://www.adafruit.com/products/1063

Please tell us more about your requirement: do you want to use the ESP8266 to actually send sound over wifi? Or do you want a loud sound to trigger something?

If you want to do the latter (detect a loud sound) then it's more efficient to have some sort of external converter/detector that processes the sound into a varying DC voltage, or sends a logical signal when the sound exceeds a preset level.

This paper has a circuit that does that. Your mic board already has an adjustable preamp, so it would replace everything from the mic to the level trimmer RV1.

- Sun Aug 09, 2015 7:37 pm #25484

Please tell us more about your requirement: do you want to use the ESP8266 to actually send sound over wifi? Or do you want a loud sound to trigger something?

Hi Kenn, I'm thinking of a wireless intercom system, so eventually I'd love to be able to relay PCM audio back and forth.