Low-cost low-power underwater acoustic data acquisition and processing system

There is a need for low-cost acoustic recording and processing instruments. Cheaply available and highly capable off-the-shelf microcontrollers and analog-to-digital converters (ADC's) allow rapid prototyping of novel systems to achieve minimum performance requirements without overhead. Combined with low-cost manufacturing capabilities for pre-assembled printed circuit boards (PCBs), acoustic recording hardware and processing have become more accessible. Prototypes can be designed and delivered for less than $100 USD per iteration. Using this methodology, we developed the Self Contained Acoustic Recording Instrument (SCARI). While consuming less than ∼40 mW, two channels of 48 ksps acoustic data can be recorded to .wav files on a microSD card with a SAMD51 microcontroller, an SGTL5000 ADC, and differential pre-amplifier on a compact PCB. Data can be saved to a microSD card or streamed via USB to be saved/processed by an embedded computer, with resources left over for simple real-time processing.