initial commit of dac files

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "adpcm-pwm-dac"
+version = "0.1.0"

Cargo.toml

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+[package]
+name = "adpcm-pwm-dac"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

src/dac.rs

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+use crate::interface::DacInterface;
+pub struct Dac<'a, T: DacInterface> {
+    output: T,
+    data: Option<&'a [u8]>,
+    index: usize,
+}
+
+impl<'a, T: DacInterface> Dac<'a, T> {
+    pub fn new(output: T) -> Self {
+        Self {
+            output,
+            data: None,
+            index: 0,
+        }
+    }
+    pub fn load_data(&mut self, data: &'a [u8]) {
+        self.data = Some(data);
+    }
+    pub fn seek_to_sample(&mut self, index: usize) {
+        self.index = index;
+    }
+    pub fn output_next(&mut self) {
+        if let Some(data) = self.data {
+            self.index = self.index + 1;
+            // reset the index to 0 if we roll over
+            if (self.index >= data.len()) {
+                self.index = 0;
+            }
+            self.output.write_amplitude(data[self.index]);             
+            // self.output.write_amplitude(100);             
+        }
+    }
+}

src/interface.rs

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+pub trait DacInterface {
+    // write the amplitude (0->100%)
+    fn write_amplitude(&mut self, amplitude: u8);
+}

src/lib.rs

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+#![no_std]
+pub mod interface;
+pub mod dac;