Alternative Hardware
As a backup option, and for some initial testing, an Adafruit MEMS microphone breakout-board was aquired. This breakout-board/microphone can be seen in the image below. It performs audio sampling with a MEMS component, sigma-delta ADC and I2S conversion. Following problems with the fabrication and construction of the project's custom PCB, this microphone was to become the hardware for the project. This decision was approved by the project supervisors.
The image above shows the I2S microphone connected up to the corresponding I2S configured pins on the Raspberry Pi. Ideally this would have acted as a comparison device to allow the custom hardware to be evaluated. Below, some test sampling, using the MEMS microphone, can be seen.
