22 lines
683 B
Rust
22 lines
683 B
Rust
use super::{Complex, ComplexExt, Lowpass, MulScaled};
|
|
|
|
#[derive(Clone, Default)]
|
|
pub struct Lockin<const N: usize> {
|
|
state: [Lowpass<N>; 2],
|
|
}
|
|
|
|
impl<const N: usize> Lockin<N> {
|
|
/// Update the lockin with a sample taken at a given phase.
|
|
pub fn update(&mut self, sample: i32, phase: i32, k: u8) -> Complex<i32> {
|
|
// Get the LO signal for demodulation and mix the sample;
|
|
let mix = Complex::from_angle(phase).mul_scaled(sample);
|
|
|
|
// Filter with the IIR lowpass,
|
|
// return IQ (in-phase and quadrature) data.
|
|
Complex {
|
|
re: self.state[0].update(mix.re, k),
|
|
im: self.state[1].update(mix.im, k),
|
|
}
|
|
}
|
|
}
|