Buffer management in line with other peripherals. Constructor and config redesign

examples/nrf/src/bin/i2s_waveform.rs

@@ -6,33 +6,29 @@ use core::f32::consts::PI;
 
 use defmt::{error, info};
 use embassy_executor::Spawner;
-use embassy_nrf::i2s::{self, Sample as _};
+use embassy_nrf::i2s::{self, Channels, Config, MasterClock, Sample as _, SampleWidth, I2S};
 use embassy_nrf::interrupt;
 use {defmt_rtt as _, panic_probe as _};
 
+type Sample = i16;
+
+const NUM_SAMPLES: usize = 6000;
+
 #[embassy_executor::main]
 async fn main(_spawner: Spawner) {
     let p = embassy_nrf::init(Default::default());
 
-    let mut config = i2s::Config::default();
-    config.mode = i2s::ExactSampleRate::_50000.into();
-    config.channels = i2s::Channels::Left;
-    config.swidth = i2s::SampleWidth::_16bit;
-    let sample_rate = config.mode.sample_rate().expect("I2S Master");
-    let inv_sample_rate = 1.0 / sample_rate as f32;
+    let master_clock: MasterClock = i2s::ExactSampleRate::_50000.into();
 
+    let sample_rate = master_clock.sample_rate();
     info!("Sample rate: {}", sample_rate);
 
-    // Wait for a button press
-    // use embassy_nrf::gpio::{Input, Pin, Pull};
-    // let mut btn1 = Input::new(p.P1_00.degrade(), Pull::Up);
-    // btn1.wait_for_low().await;
+    let config = Config::default()
+        .sample_width(SampleWidth::_16bit)
+        .channels(Channels::MonoLeft);
 
     let irq = interrupt::take!(I2S);
-    let mut i2s = i2s::I2S::new(p.I2S, irq, p.P0_28, p.P0_29, p.P0_31, p.P0_27, p.P0_30, config).output();
-
-    type Sample = i16;
-    const NUM_SAMPLES: usize = 6000;
+    let mut output_stream = I2S::master(p.I2S, irq, p.P0_25, p.P0_26, p.P0_27, master_clock, config).output(p.P0_28);
 
     let mut buffers: [i2s::AlignedBuffer<Sample, NUM_SAMPLES>; 3] = [
         i2s::AlignedBuffer::default(),
@@ -40,36 +36,16 @@ async fn main(_spawner: Spawner) {
         i2s::AlignedBuffer::default(),
     ];
 
-    let mut carrier = SineOsc::new();
+    let mut waveform = Waveform::new(1.0 / sample_rate as f32);
 
-    let mut freq_mod = SineOsc::new();
-    freq_mod.set_frequency(8.0, inv_sample_rate);
-    freq_mod.set_amplitude(1.0);
+    waveform.process(&mut buffers[0]);
+    waveform.process(&mut buffers[1]);
 
-    let mut amp_mod = SineOsc::new();
-    amp_mod.set_frequency(16.0, inv_sample_rate);
-    amp_mod.set_amplitude(0.5);
-
-    let mut generate = |buf: &mut [Sample]| {
-        for sample in &mut buf.chunks_mut(1) {
-            let freq_modulation = bipolar_to_unipolar(freq_mod.generate());
-            carrier.set_frequency(220.0 + 440.0 * freq_modulation, inv_sample_rate);
-            let amp_modulation = bipolar_to_unipolar(amp_mod.generate());
-            carrier.set_amplitude(amp_modulation);
-            let signal = carrier.generate();
-            let value = (Sample::SCALE as f32 * signal) as Sample;
-            sample[0] = value;
-        }
-    };
-
-    generate(buffers[0].as_mut());
-    generate(buffers[1].as_mut());
-
-    i2s.start(buffers[0].as_ref()).await.expect("I2S Start");
+    output_stream.start(&buffers[0]).await.expect("I2S Start");
 
     let mut index = 1;
     loop {
-        if let Err(err) = i2s.send(buffers[index].as_ref()).await {
+        if let Err(err) = output_stream.send_from_ram(&buffers[index]).await {
             error!("{}", err);
         }
 
@@ -77,11 +53,54 @@ async fn main(_spawner: Spawner) {
         if index >= 3 {
             index = 0;
         }
-        generate(buffers[index].as_mut());
+
+        waveform.process(&mut buffers[index]);
+    }
+}
+
+struct Waveform {
+    inv_sample_rate: f32,
+    carrier: SineOsc,
+    freq_mod: SineOsc,
+    amp_mod: SineOsc,
+}
+
+impl Waveform {
+    fn new(inv_sample_rate: f32) -> Self {
+        let carrier = SineOsc::new();
+
+        let mut freq_mod = SineOsc::new();
+        freq_mod.set_frequency(8.0, inv_sample_rate);
+        freq_mod.set_amplitude(1.0);
+
+        let mut amp_mod = SineOsc::new();
+        amp_mod.set_frequency(16.0, inv_sample_rate);
+        amp_mod.set_amplitude(0.5);
+
+        Self {
+            inv_sample_rate,
+            carrier,
+            freq_mod,
+            amp_mod,
+        }
+    }
+
+    fn process(&mut self, buf: &mut [Sample]) {
+        for sample in buf.chunks_mut(1) {
+            let freq_modulation = bipolar_to_unipolar(self.freq_mod.generate());
+            self.carrier
+                .set_frequency(110.0 + 440.0 * freq_modulation, self.inv_sample_rate);
+
+            let amp_modulation = bipolar_to_unipolar(self.amp_mod.generate());
+            self.carrier.set_amplitude(amp_modulation);
+
+            let signal = self.carrier.generate();
+
+            sample[0] = (Sample::SCALE as f32 * signal) as Sample;
+        }
     }
 }
 
-#[derive(Clone)]
 struct SineOsc {
     amplitude: f32,
     modulo: f32,