SamplingConfig

SamplingConfig represents the sampling frequency of Modulation or STM. The sampling frequency must be the ultrasound frequency (40 kHz) divided by an integer.

Rust

SamplingConfig::new(NonZeroU16::new(10).unwrap());
SamplingConfig::new(4. * kHz);
SamplingConfig::new(Duration::from_micros(250));
SamplingConfig::new(Nearest(4. * kHz));
SamplingConfig::new(Nearest(Duration::from_micros(250)));

Python

SamplingConfig(10)
SamplingConfig(4.0 * kHz)
SamplingConfig(Duration.from_micros(250))
SamplingConfig(Nearest(4.0 * kHz))
SamplingConfig(Nearest(Duration.from_micros(250)))

C#

new SamplingConfig(10);
new SamplingConfig(4.0f * kHz);
new SamplingConfig(TimeSpan.FromMicroseconds(250));
new SamplingConfig(Nearest(4.0f * kHz));
new SamplingConfig(Nearest(TimeSpan.FromMicroseconds(250)));

SamplingConfig::new accepts NonZeroU16 / Freq<f32> / Duration / Nearest<Freq<f32>> / Nearest<Duration>. All of the above represent 4 kHz (division ratio 10) and are equivalent to one another.

Internal Representation

SamplingConfig can be specified as one of the following. Internally, it is ultimately converted to a division ratio (u16).

Specification method	Type
Division ratio	NonZeroU16
Frequency	Freq<f32>
Period	Duration

The relationship between the division ratio , the sampling frequency , and the sampling period is as follows.

When specified by frequency or period, it is an error if it does not evenly divide 40 kHz (i.e., does not yield an integer division ratio). To round an indivisible value to the nearest division ratio, wrap the frequency/period in Nearest.

Presets

Frequently used constants are provided in advance.

Constant	Sampling frequency	Division ratio
FREQ_40K	40 kHz	1
FREQ_4K	4 kHz	10