From 311103b79eb800a756c7ae5b771921322ff92459 Mon Sep 17 00:00:00 2001
From: Diego Barrios Romero <eldruin@gmail.com>
Date: Sat, 17 Nov 2018 07:43:01 +0100
Subject: Add support for setting the comparator queue

---
 src/devices/features/tier2.rs | 18 +++++++++++++++++-
 src/lib.rs                    | 13 +++++++++++++
 tests/tier2_i2c.rs            | 11 ++++++++++-
 3 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/src/devices/features/tier2.rs b/src/devices/features/tier2.rs
index 17502e6..25b618a 100644
--- a/src/devices/features/tier2.rs
+++ b/src/devices/features/tier2.rs
@@ -3,7 +3,7 @@
 //! These are the features included only in ADS1x14, ADS1x15
 
 use { Ads1x1x, Error, interface, ic, ComparatorMode, ComparatorPolarity,
-      ComparatorLatching, Register, BitFlags, conversion };
+      ComparatorLatching, ComparatorQueue, Register, BitFlags, conversion };
 
 impl<DI, IC, CONV, MODE, E> Ads1x1x<DI, IC, CONV, MODE>
 where
@@ -58,6 +58,22 @@ where
         self.config = config;
         Ok(())
     }
+
+    /// Activate comparator and set the alert queue
+    ///
+    /// The comparator can be disabled with [`disable_comparator()`](struct.Ads1x1x.html#method.disable_comparator)
+    pub fn set_comparator_queue(&mut self, queue: ComparatorQueue) -> Result<(), Error<E>> {
+        let config;
+        match queue {
+            ComparatorQueue::One  => config = self.config.with_low( BitFlags::COMP_QUE1).with_low( BitFlags::COMP_QUE0),
+            ComparatorQueue::Two  => config = self.config.with_low( BitFlags::COMP_QUE1).with_high(BitFlags::COMP_QUE0),
+            ComparatorQueue::Four => config = self.config.with_high(BitFlags::COMP_QUE1).with_low( BitFlags::COMP_QUE0)
+        }
+        self.iface.write_register(Register::CONFIG, config.bits)?;
+        self.config = config;
+        Ok(())
+    }
+
     /// Disable comparator (default)
     ///
     /// This will set the ALERT/RDY pin to high-impedance.
diff --git a/src/lib.rs b/src/lib.rs
index b7b3ce0..9680ea3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -12,6 +12,7 @@
 //! - Set the comparator mode. See: [`set_comparator_mode()`].
 //! - Set the comparator polarity. See: [`set_comparator_polarity()`].
 //! - Set the comparator latching. See: [`set_comparator_latching()`].
+//! - Set the comparator queue. See: [`set_comparator_queue()`].
 //! - Disable the comparator. See: [`disable_comparator()`].
 //!
 //! [`into_continuous()`]: struct.Ads1x1x.html#method.into_continuous
@@ -21,6 +22,7 @@
 //! [`set_comparator_mode()`]: struct.Ads1x1x.html#method.set_comparator_mode
 //! [`set_comparator_polarity()`]: struct.Ads1x1x.html#method.set_comparator_polarity
 //! [`set_comparator_latching()`]: struct.Ads1x1x.html#method.set_comparator_latching
+//! [`set_comparator_queue()`]: struct.Ads1x1x.html#method.set_comparator_queue
 //! [`disable_comparator()`]: struct.Ads1x1x.html#method.disable_comparator
 //!
 //! ## The devices
@@ -220,6 +222,17 @@ pub enum ComparatorLatching {
     Latching
 }
 
+/// Comparator alert queue (only for ADS1x14, ADS1x15)
+#[derive(Debug, Clone, PartialEq)]
+pub enum ComparatorQueue {
+    /// Activate comparator and assert after one conversion exceeding thresholds
+    One,
+    /// Activate comparator and assert after two consecutive conversions exceeding thresholds
+    Two,
+    /// Activate comparator and assert after four consecutive conversions exceeding thresholds
+    Four,
+}
+
 /// Possible slave addresses
 #[derive(Debug, Clone)]
 pub enum SlaveAddr {
diff --git a/tests/tier2_i2c.rs b/tests/tier2_i2c.rs
index 75c4b5f..a4c4df3 100644
--- a/tests/tier2_i2c.rs
+++ b/tests/tier2_i2c.rs
@@ -1,7 +1,8 @@
 extern crate embedded_hal_mock as hal;
 use hal::i2c::Transaction as I2cTrans;
 extern crate ads1x1x;
-use ads1x1x::{ ComparatorMode, ComparatorPolarity, ComparatorLatching};
+use ads1x1x::{ ComparatorMode, ComparatorPolarity, ComparatorLatching,
+               ComparatorQueue };
 
 #[macro_use]
 mod common;
@@ -58,3 +59,11 @@ fn can_disable_comparator() {
     dev.disable_comparator().unwrap();
     destroy_ads1014(dev);
 }
+
+mod can_set_comparator_queue {
+    use super::*;
+    config_test!(one,  set_comparator_queue, ComparatorQueue::One,  Config::default().with_low( BitFlags::COMP_QUE1).with_low( BitFlags::COMP_QUE0));
+    config_test!(two,  set_comparator_queue, ComparatorQueue::Two,  Config::default().with_low( BitFlags::COMP_QUE1).with_high(BitFlags::COMP_QUE0));
+    config_test!(four, set_comparator_queue, ComparatorQueue::Four, Config::default().with_high(BitFlags::COMP_QUE1).with_low( BitFlags::COMP_QUE0));
+}
+
-- 
cgit v1.2.3-54-g00ecf