blocking DAC trait

src/blocking/dac.rs

@@ -0,0 +1,14 @@
+//! Blocking DAC trait for single channel digital to analog conversion
+
+/// A single DAC channel. Word is the type used to represent a single sample, this would typically
+/// be u8, u16 or u32.
+/// Note that not all bits will always be used. A 12 bit DAC for example will probably use u16 here
+/// <DISCUSSION> should we prescribe to use the most significant bits here for compat between word
+///   sizes?
+pub trait DAC<WORD> {
+    /// Error type returned by DAC methods
+    type Error;
+
+    /// Set the output of the DAC
+    fn try_set_output(&mut self, value: WORD) -> Result<(), Self::Error>;
+}

src/blocking/mod.rs

@@ -4,6 +4,7 @@
 //! traits. To save boilerplate when that's the case a `Default` marker trait may be provided.
 //! Implementing that marker trait will opt in your type into a blanket implementation.
 
+pub mod dac;
 pub mod delay;
 pub mod i2c;
 pub mod rng;