I'm using teensy 3.2 with the audio adaptor.
The audio signal come into the mic port of audio adaptor, which has the voltage around 0 volt (positive or negative).
But the input range of ADC on teensy is 0 to 3.3V which means we can't get the signal when it is negative.
Is there some way to get the raw data from the microphone?
Maybe to use an external circuit to improve the DC level of signal is a choice. But is there some other ways?
I need to do some signal processing with the data from microphone, and I need to do the signal processing immediately after it comes into the audio board.