Split common functions into tier1 features module

4 files changed, 105 insertions, 17 deletions

diff --git a/src/devices/ads1x1x/common.rs b/src/devices/ads1x1x/common.rs
index ce8a67a..5abb99c 100644
--- a/src/devices/ads1x1x/common.rs
+++ b/src/devices/ads1x1x/common.rs
@@ -1,11 +1,12 @@
 //! Common functions
 
-use { Ads1x1x, DataRate, Error, Register, BitFlags, interface };
+use { Ads1x1x, Error, Register, BitFlags, interface, Config, ic };
 use super::OperatingMode;
 
 impl<DI, IC, MODE, E> Ads1x1x<DI, IC, MODE>
 where
-    DI: interface::WriteData<Error = E>
+    DI: interface::WriteData<Error = E>,
+    IC: ic::Resolution
 {
     pub(super) fn set_operating_mode(&mut self, mode: OperatingMode) -> Result<(), Error<E>> {
         let config;
@@ -18,20 +19,18 @@ where
         Ok(())
     }
 
-    /// Set data rate
-    pub fn set_data_rate(&mut self, rate: DataRate) -> Result<(), Error<E>> {
-        let config;
-        match rate {
-            DataRate::Sps128  => config = self.config.with_low( BitFlags::DR2).with_low( BitFlags::DR1).with_low( BitFlags::DR0),
-            DataRate::Sps250  => config = self.config.with_low( BitFlags::DR2).with_low( BitFlags::DR1).with_high(BitFlags::DR0),
-            DataRate::Sps490  => config = self.config.with_low( BitFlags::DR2).with_high(BitFlags::DR1).with_low( BitFlags::DR0),
-            DataRate::Sps920  => config = self.config.with_low( BitFlags::DR2).with_high(BitFlags::DR1).with_high(BitFlags::DR0),
-            DataRate::Sps1600 => config = self.config.with_high(BitFlags::DR2).with_low( BitFlags::DR1).with_low( BitFlags::DR0),
-            DataRate::Sps2400 => config = self.config.with_high(BitFlags::DR2).with_low( BitFlags::DR1).with_high(BitFlags::DR0),
-            DataRate::Sps3300 => config = self.config.with_high(BitFlags::DR2).with_high(BitFlags::DR1).with_low( BitFlags::DR0),
-        }
-        self.iface.write_register(Register::CONFIG, config.bits)?;
-        self.config = config;
-        Ok(())
+    /// Reset the internal state of this driver to the default values.
+    ///
+    /// *Note:* This does not alter the state or configuration of the device.
+    ///
+    /// This resets the cached configuration register value in this driver to
+    /// the power-up (reset) configuration of the device.
+    ///
+    /// This needs to be called after performing a reset on the device, for
+    /// example through an I2C general-call Reset command, which was not done
+    /// through this driver to ensure that the configurations in the device
+    /// and in the driver match.
+    pub fn reset_internal_driver_state(&mut self) {
+        self.config = Config::default();
     }
 }
diff --git a/src/devices/ads1x1x/features/mod.rs b/src/devices/ads1x1x/features/mod.rs
new file mode 100644
index 0000000..ad26258
--- /dev/null
+++ b/src/devices/ads1x1x/features/mod.rs
@@ -0,0 +1,5 @@
+//! Implementation of IC features separated in tiers depending on the hardware
+//! support.
+
+mod tier1;
+
diff --git a/src/devices/ads1x1x/features/tier1.rs b/src/devices/ads1x1x/features/tier1.rs
new file mode 100644
index 0000000..9f72b77
--- /dev/null
+++ b/src/devices/ads1x1x/features/tier1.rs
@@ -0,0 +1,83 @@
+//! Common functions
+
+use { Ads1x1x, DataRate, Error, Register, BitFlags, interface, ic };
+
+impl<DI, IC, MODE, E> Ads1x1x<DI, IC, MODE>
+where
+    DI: interface::WriteData<Error = E>,
+    IC: ic::Resolution
+{
+    /// Set data rate
+    pub fn set_data_rate(&mut self, rate: DataRate) -> Result<(), Error<E>> {
+        let config;
+        match rate {
+            DataRate::Sps128  => config = self.config.with_low( BitFlags::DR2).with_low( BitFlags::DR1).with_low( BitFlags::DR0),
+            DataRate::Sps250  => config = self.config.with_low( BitFlags::DR2).with_low( BitFlags::DR1).with_high(BitFlags::DR0),
+            DataRate::Sps490  => config = self.config.with_low( BitFlags::DR2).with_high(BitFlags::DR1).with_low( BitFlags::DR0),
+            DataRate::Sps920  => config = self.config.with_low( BitFlags::DR2).with_high(BitFlags::DR1).with_high(BitFlags::DR0),
+            DataRate::Sps1600 => config = self.config.with_high(BitFlags::DR2).with_low( BitFlags::DR1).with_low( BitFlags::DR0),
+            DataRate::Sps2400 => config = self.config.with_high(BitFlags::DR2).with_low( BitFlags::DR1).with_high(BitFlags::DR0),
+            DataRate::Sps3300 => config = self.config.with_high(BitFlags::DR2).with_high(BitFlags::DR1).with_low( BitFlags::DR0),
+        }
+        self.iface.write_register(Register::CONFIG, config.bits)?;
+        self.config = config;
+        Ok(())
+    }
+
+    /// Set comparator lower threshold
+    pub fn set_low_threshold(&mut self, value: i16) -> Result<(), Error<E>> {
+        let register_value = convert_threshold::<IC, E>(value)?;
+        self.iface.write_register(Register::LOW_TH, register_value)
+    }
+
+    /// Set comparator upper threshold
+    pub fn set_high_threshold(&mut self, value: i16) -> Result<(), Error<E>> {
+        let register_value = convert_threshold::<IC, E>(value)?;
+        self.iface.write_register(Register::HIGH_TH, register_value)
+    }
+}
+
+fn convert_threshold<IC, E>(value: i16) -> Result<u16, Error<E>>
+where
+    IC: ic::Resolution
+{
+    if IC::BITS == ic::ResolutionBits::_12 {
+        if value < -2048 || value > 2047 {
+            return Err(Error::InvalidInputData);
+        }
+        Ok((value << 4) as u16)
+    }
+    else {
+        Ok(value as u16)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn assert_invalid_input_data<E>(result: Result<u16, Error<E>>) {
+        match result {
+            Err(Error::InvalidInputData) => (),
+            _ => panic!("InvalidInputData error was not returned.")
+        }
+    }
+
+    #[test]
+    fn convert_12_bits() {
+        assert_invalid_input_data(convert_threshold::<ic::Ads1013, ()>(2048));
+        assert_invalid_input_data(convert_threshold::<ic::Ads1013, ()>(-2049));
+
+        assert_eq!(     0, convert_threshold::<ic::Ads1013, ()>(0).unwrap());
+        assert_eq!(0x7FF0, convert_threshold::<ic::Ads1013, ()>(2047).unwrap());
+        assert_eq!(0x8000, convert_threshold::<ic::Ads1013, ()>(-2048).unwrap());
+        assert_eq!(0xFFF0, convert_threshold::<ic::Ads1013, ()>(-1).unwrap());
+    }
+
+    #[test]
+    fn convert_16_bits() {
+        assert_eq!(0x7FFF, convert_threshold::<ic::Ads1113, ()>(32767).unwrap());
+        assert_eq!(0x8000, convert_threshold::<ic::Ads1113,()>(-32768).unwrap());
+    }
+}
+
diff --git a/src/devices/ads1x1x/mod.rs b/src/devices/ads1x1x/mod.rs
index b7146a9..95d8907 100644
--- a/src/devices/ads1x1x/mod.rs
+++ b/src/devices/ads1x1x/mod.rs
@@ -7,3 +7,4 @@ enum OperatingMode {
 
 mod common;
 mod mode;
+mod features;