From 8d4a04d3545b5173bea6eeea81be0581e6134dbf Mon Sep 17 00:00:00 2001
From: Mendelt Siebenga <msiebenga@gmail.com>
Date: Sun, 19 Jul 2020 15:36:07 +0200
Subject: [PATCH 1/2] first naive implementation of dac trait

---
 src/blocking/dac.rs | 10 ++++++++++
 src/blocking/mod.rs |  1 +
 2 files changed, 11 insertions(+)
 create mode 100644 src/blocking/dac.rs

diff --git a/src/blocking/dac.rs b/src/blocking/dac.rs
new file mode 100644
index 000000000..73289fea8
--- /dev/null
+++ b/src/blocking/dac.rs
@@ -0,0 +1,10 @@
+//! Trait for digital to analog conversion
+
+/// Represents a single DAC channel.
+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>;
+}
diff --git a/src/blocking/mod.rs b/src/blocking/mod.rs
index 3a050f6d2..3255216c9 100644
--- a/src/blocking/mod.rs
+++ b/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;

From 3e13ccfec103aba319d18366a614b65734be4dde Mon Sep 17 00:00:00 2001
From: Mendelt Siebenga <msiebenga@gmail.com>
Date: Thu, 23 Jul 2020 16:00:10 +0200
Subject: [PATCH 2/2] some docstrings

---
 src/blocking/dac.rs | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/blocking/dac.rs b/src/blocking/dac.rs
index 73289fea8..6e99cb947 100644
--- a/src/blocking/dac.rs
+++ b/src/blocking/dac.rs
@@ -1,6 +1,10 @@
-//! Trait for digital to analog conversion
+//! Blocking DAC trait for single channel digital to analog conversion
 
-/// Represents a single DAC channel.
+/// 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;