Add support for setting the comparator polarity

2 files changed, 24 insertions, 1 deletions

diff --git a/src/devices/ads1x1x/features/tier2.rs b/src/devices/ads1x1x/features/tier2.rs
index d238691..7d22796 100644
--- a/src/devices/ads1x1x/features/tier2.rs
+++ b/src/devices/ads1x1x/features/tier2.rs
@@ -2,7 +2,8 @@
 //!
 //! These are the features included only in ADS1x14, ADS1x15
 
-use { Ads1x1x, Error, interface, ic, ComparatorMode, Register, BitFlags };
+use { Ads1x1x, Error, interface, ic, ComparatorMode, ComparatorPolarity,
+      Register, BitFlags };
 
 impl<DI, IC, MODE, E> Ads1x1x<DI, IC, MODE>
 where
@@ -20,4 +21,16 @@ where
         self.config = config;
         Ok(())
     }
+
+    /// Set comparator polarity
+    pub fn set_comparator_polarity(&mut self, polarity: ComparatorPolarity) -> Result<(), Error<E>> {
+        let config;
+        match polarity {
+            ComparatorPolarity::ActiveLow  => config = self.config.with_low( BitFlags::COMP_POL),
+            ComparatorPolarity::ActiveHigh => config = self.config.with_high(BitFlags::COMP_POL)
+        }
+        self.iface.write_register(Register::CONFIG, config.bits)?;
+        self.config = config;
+        Ok(())
+    }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 21b63c5..7dc1388 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -124,6 +124,15 @@ pub enum ComparatorMode {
     Window
 }
 
+/// Comparator polarity (only for ADS1x14, ADS1x15)
+#[derive(Debug, Clone)]
+pub enum ComparatorPolarity {
+    /// Active low (default)
+    ActiveLow,
+    /// Active high
+    ActiveHigh
+}
+
 /// Possible slave addresses
 #[derive(Debug, Clone)]
 pub enum SlaveAddr {
@@ -168,6 +177,7 @@ impl BitFlags {
     const DR1          : u16 = 0b0000_0000_0100_0000;
     const DR0          : u16 = 0b0000_0000_0010_0000;
     const COMP_MODE    : u16 = 0b0000_0000_0001_0000;
+    const COMP_POL     : u16 = 0b0000_0000_0000_1000;
 }