SparkFun Forums 

Where electronics enthusiasts find answers.

Have questions about a SparkFun product or board? This is the place to be.
By rbwilcoxon11
#200480
I have a project where I am trying to get audio from an Android headset accessory into a teensy audio board line in using the LMV358 op Amp breakout board.

I am not able to get any signal from the LMV358, only a floating voltage at around 2.5v.

I am using this information for the arduino spec to wire it: https://source.android.com/devices/acce ... adset-spec

Essentially, I am wiring the mic out to the input of the LMV358, and plugging the output of the LMV358 straight to the line in of the teensy audio board.

My question is: do I need additional circuit components? Are my assumptions correct that this setup should work?
By Markmilleru2
#200671
rbwilcoxon11 wrote: Wed Sep 26, 2018 11:41 am I have a project where I am trying to get audio from an Android headset accessory into a teensy audio board line in using the LMV358 op Amp breakout board.

I am not able to get any signal from the LMV358, only a floating voltage at around 2.5v.

I am using this information for the arduino spec to wire it:best cordless drill best miter saw best gaming laptop under 500 best reel mowerEssentially, I am wiring the mic out to the input of the LMV358, and plugging the output of the LMV358 straight to the line in of the teensy audio board.

My question is: do I need additional circuit components? Are my assumptions correct that this setup should work?
I am also facing same problem
By UhClem
#200687
It is difficult to tell from what I have found but it is possible that the mic requires a DC bias voltage to operate. The documents mention a resistor (2.2K) in series with a small voltage (2.2V) but it isn't clear if that is needed by the mic or just to detect switch closures.