From 8502ed75bf8d3e8df1eb5f1b5576079f55c6e13e Mon Sep 17 00:00:00 2001
From: sigil-03 <sigil@glyphs.tech>
Date: Sun, 27 Jul 2025 14:58:02 -0600
Subject: [PATCH] initial commit of dac files

---
 .gitignore       |  1 +
 Cargo.lock       |  7 +++++++
 Cargo.toml       |  6 ++++++
 src/dac.rs       | 33 +++++++++++++++++++++++++++++++++
 src/interface.rs |  4 ++++
 src/lib.rs       |  3 +++
 6 files changed, 54 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Cargo.lock
 create mode 100644 Cargo.toml
 create mode 100644 src/dac.rs
 create mode 100644 src/interface.rs
 create mode 100644 src/lib.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..ea8c4bf
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000..4e404bc
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,7 @@
+# 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"
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..0f74483
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "adpcm-pwm-dac"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
diff --git a/src/dac.rs b/src/dac.rs
new file mode 100644
index 0000000..32ead8f
--- /dev/null
+++ b/src/dac.rs
@@ -0,0 +1,33 @@
+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);             
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/interface.rs b/src/interface.rs
new file mode 100644
index 0000000..ea18854
--- /dev/null
+++ b/src/interface.rs
@@ -0,0 +1,4 @@
+pub trait DacInterface {
+    // write the amplitude (0->100%)
+    fn write_amplitude(&mut self, amplitude: u8);
+}
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..d34c0f8
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,3 @@
+#![no_std]
+pub mod interface;
+pub mod dac;
\ No newline at end of file