Description
This tiny MEMS microphone breakout board from Adafruit is based on the SPW2430 all in one microphone and amplifier chipset. The microphone is ideal for voice recording, audio detection, and audio sampling in the range of 100Hz to 10KHz.
The breakout has a built in 3V regulator and filter caps – and requires no additional components! The output peak-to-peak voltage has a 0.67V DC bias and about 100mVpp (peak-to-peak) when talking near the microphone, which is good for attaching to something that expects ‘line level’ input without clipping. The peak-to-peak can be as high as 1Vpp if there’s a very loud sound.
To use the board, simply connect 3.3V to 5VDC to the “VDC” pin, and the ground from your power supply to “GND”. Best results will be achieved when using a low-noise power source – if powering from an Arduino, this would be the 3.3V supply. The audio waveform will come out of the DC pin. The output will have a DC bias of 0.67V so when its perfectly quiet that’s what you’ll read, there’s a little drift. If the audio equipment you’re using requires AC coupled audio, you can grab the signal out of the AC pin, which has a 10uF capacitor in series.
The output pin is not designed to drive speakers or anything but the smallest in-ear headphones – you’ll need an audio amplifier (such as Adafruit’s 3.7W stereo amp) if you want to connect the amp directly to speakers. If you’re connecting to a microcontroller pin, you don’t need an amplifier or decoupling capacitor – connect the DC pin directly to the microcontroller ADC pin.