I would like to construct a simple system for automatic playback of ultrasound signals at low levels for calibration purposes on an underwater recording rig. Can anyone point to a suitable DAC (digital to Analogue Converter) shield for Arduino or similar that could be used for this?
Some more details of the requirements: I want to send out a series of porpoise-like clicks, each 100 µs long, in series with different amplitudes and inter-click intervals. I can see two simple approaches that could work:
A) Store a few seconds long sequence of clicks in suitable memory and play entire file through DAC with regular intervals. Requires a few Mb of memory to play back a signal a few seconds long at 500 kHz sampling rate.
B) Store a single click in Arduino onboard memory (1 kB for a 100 µs signal at 500 kHz sample rate) and adjust playback amplitude and inter-click interval on a click-by click basis by the Arduino program.
Suggestions to hardware suited for this and possible alternative ways of implementation highly welcomed.