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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.

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    $\begingroup$ What sort of source levels are you aiming at ? i.e. given the transducer you are planning to use, how many volts will you need from the ADC to generate the required signal ? $\endgroup$ Jul 18, 2022 at 20:45
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    $\begingroup$ Very low source levels, definitely not higher than 140 dB re 1 µPa, which means that output in the range of a few V or lower with a suitable hydrophone. Planning on using a B&K 8103, which has a transmitting sensitivity around 130-135 dB re 1 µPa/V in the 100-150 kHz range. $\endgroup$
    – user18
    Jul 19, 2022 at 12:00

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Would this not suit your needs?

https://oceansonics.com/products/ictalk-smart-projector/

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