Simplify `SlaveAddr`. (#21)

* Simplify `SlaveAddr`.

* Update changelog.

* Update CHANGELOG.md

---------

Co-authored-by: Diego Barrios Romero <eldruin@gmail.com>

9 files changed, 42 insertions, 99 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a0587c..cb23a44 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,7 +12,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Add default for `ComparatorQueue`.
 
 ### Changed
-- Updated `embedded-hal` to version `1`, `read` in one-shot mode is therefore only an inherent method.
+- [breaking-change] Updated `embedded-hal` to version `1`, `read` in one-shot mode is therefore only an inherent method.
+- [breaking-change] Simplified `SlaveAddr` enum.
 - Raised MSRV to 1.62.0.
 
 ### Removed
diff --git a/README.md b/README.md
index 070af22..dbdad5d 100644
--- a/README.md
+++ b/README.md
@@ -85,8 +85,7 @@ use ads1x1x::{channel, Ads1x1x, SlaveAddr};
 
 fn main() {
     let dev = I2cdev::new("/dev/i2c-1").unwrap();
-    let address = SlaveAddr::default();
-    let mut adc = Ads1x1x::new_ads1013(dev, address);
+    let mut adc = Ads1x1x::new_ads1013(dev, SlaveAddr::default());
     let value = block!(adc.read(channel::DifferentialA0A1)).unwrap();
     println!("Measurement: {}", value);
     // get I2C device back
diff --git a/examples/all_channels.rs b/examples/all_channels.rs
index ddf8326..39687ca 100644
--- a/examples/all_channels.rs
+++ b/examples/all_channels.rs
@@ -5,8 +5,7 @@ use ads1x1x::{channel, Ads1x1x, SlaveAddr};
 
 fn main() {
     let dev = I2cdev::new("/dev/i2c-1").unwrap();
-    let address = SlaveAddr::default();
-    let mut adc = Ads1x1x::new_ads1015(dev, address);
+    let mut adc = Ads1x1x::new_ads1015(dev, SlaveAddr::default());
     let values = [
         block!(adc.read(channel::SingleA0)).unwrap(),
         block!(adc.read(channel::SingleA1)).unwrap(),
diff --git a/examples/linux.rs b/examples/linux.rs
index 55eab64..c3c9d54 100644
--- a/examples/linux.rs
+++ b/examples/linux.rs
@@ -5,8 +5,7 @@ use ads1x1x::{channel, Ads1x1x, SlaveAddr};
 
 fn main() {
     let dev = I2cdev::new("/dev/i2c-1").unwrap();
-    let address = SlaveAddr::default();
-    let mut adc = Ads1x1x::new_ads1013(dev, address);
+    let mut adc = Ads1x1x::new_ads1013(dev, SlaveAddr::default());
     let value = block!(adc.read(channel::DifferentialA0A1)).unwrap();
     println!("Measurement: {}", value);
     // get I2C device back
diff --git a/examples/trait.rs b/examples/trait.rs
index 070d89c..3eff5b5 100644
--- a/examples/trait.rs
+++ b/examples/trait.rs
@@ -14,8 +14,7 @@ pub fn read<E, A: DynamicOneShot<Error = E>>(adc: &mut A) -> i16 {
 
 fn main() {
     let dev = I2cdev::new("/dev/i2c-1").unwrap();
-    let address = SlaveAddr::default();
-    let mut adc = Ads1x1x::new_ads1115(dev, address);
+    let mut adc = Ads1x1x::new_ads1115(dev, SlaveAddr::default());
 
     let value = read(&mut adc);
     println!("Measurement: {}", value);
diff --git a/examples/typed.rs b/examples/typed.rs
index 572754f..797b69e 100644
--- a/examples/typed.rs
+++ b/examples/typed.rs
@@ -21,8 +21,7 @@ pub fn read(adc: &mut Adc) -> i16 {
 
 fn main() {
     let dev = I2cdev::new("/dev/i2c-1").unwrap();
-    let address = SlaveAddr::default();
-    let mut adc = Ads1x1x::new_ads1115(dev, address);
+    let mut adc = Ads1x1x::new_ads1115(dev, SlaveAddr::default());
 
     let value = read(&mut adc);
     println!("Measurement: {}", value);
diff --git a/src/construction.rs b/src/construction.rs
index 7ac128f..13a2350 100644
--- a/src/construction.rs
+++ b/src/construction.rs
@@ -1,6 +1,6 @@
 //! Constructor/destructor functions.
 
-use crate::{ic, mode, Ads1x1x, Config, FullScaleRange, SlaveAddr, DEVICE_BASE_ADDRESS};
+use crate::{ic, mode, Ads1x1x, Config, FullScaleRange, SlaveAddr};
 use core::marker::PhantomData;
 
 macro_rules! impl_new_destroy {
@@ -13,7 +13,7 @@ macro_rules! impl_new_destroy {
             pub fn $create(i2c: I2C, address: SlaveAddr) -> Self {
                 Ads1x1x {
                     i2c,
-                    address: address.addr(DEVICE_BASE_ADDRESS),
+                    address: address.bits(),
                     config: Config::default(),
                     fsr: FullScaleRange::default(),
                     a_conversion_was_started: false,
diff --git a/src/lib.rs b/src/lib.rs
index c020afc..277b2ad 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -84,46 +84,28 @@
 //!
 //! [driver-examples]: https://github.com/eldruin/driver-examples
 //!
-//! ### Create a driver instance for the ADS1013
+//! ### Create a driver instance for an ADS1013 with the default address.
 //!
 //! ```no_run
 //! use linux_embedded_hal::I2cdev;
 //! use ads1x1x::{Ads1x1x, SlaveAddr};
 //!
 //! let dev = I2cdev::new("/dev/i2c-1").unwrap();
-//! let address = SlaveAddr::default();
-//! let adc = Ads1x1x::new_ads1013(dev, address);
+//! let adc = Ads1x1x::new_ads1013(dev, SlaveAddr::default());
 //! // do something...
 //!
 //! // get the I2C device back
 //! let dev = adc.destroy_ads1013();
 //! ```
 //!
-//! ### Create a driver instance for the ADS1013 with an alternative address (method 1)
+//! ### Create a driver instance for an ADS1013 with the ADDR pin connected to SDA.
 //!
 //! ```no_run
 //! use linux_embedded_hal::I2cdev;
 //! use ads1x1x::{Ads1x1x, SlaveAddr};
 //!
 //! let dev = I2cdev::new("/dev/i2c-1").unwrap();
-//! let (bit1, bit0) = (true, false); // last two bits of address
-//! let address = SlaveAddr::Alternative(bit1, bit0);
-//! let adc = Ads1x1x::new_ads1013(dev, address);
-//! ```
-
-//! ### Create a driver instance for the ADS1013 with an alternative address (method 2)
-//!
-//! Using helper `SlaveAddr` creation method depending on the connection of
-//! the `ADDR` pin.
-//!
-//! ```no_run
-//! use linux_embedded_hal::I2cdev;
-//! use ads1x1x::{Ads1x1x, SlaveAddr};
-//!
-//! let dev = I2cdev::new("/dev/i2c-1").unwrap();
-//! // `ADDR` pin connected to SDA results in the 0x4A effective address
-//! let address = SlaveAddr::new_sda();
-//! let adc = Ads1x1x::new_ads1013(dev, address);
+//! let adc = Ads1x1x::new_ads1013(dev, SlaveAddr::Sda);
 //! ```
 //!
 //! ### Make a one-shot measurement
@@ -149,8 +131,7 @@
 //! use ads1x1x::{Ads1x1x, ModeChangeError, SlaveAddr};
 //!
 //! let dev = I2cdev::new("/dev/i2c-1").unwrap();
-//! let address = SlaveAddr::default();
-//! let adc = Ads1x1x::new_ads1013(dev, address);
+//! let adc = Ads1x1x::new_ads1013(dev, SlaveAddr::default());
 //! match adc.into_continuous() {
 //!     Err(ModeChangeError::I2C(e, adc)) => /* mode change failed handling */ panic!(),
 //!     Ok(mut adc) => {
@@ -170,8 +151,7 @@
 //! use ads1x1x::{Ads1x1x, DataRate16Bit, SlaveAddr};
 //!
 //! let dev = I2cdev::new("/dev/i2c-1").unwrap();
-//! let address = SlaveAddr::default();
-//! let mut adc = Ads1x1x::new_ads1115(dev, address);
+//! let mut adc = Ads1x1x::new_ads1115(dev, SlaveAddr::default());
 //! adc.set_data_rate(DataRate16Bit::Sps860).unwrap();
 //! ```
 //!
@@ -204,8 +184,6 @@
 #![deny(missing_docs)]
 #![no_std]
 
-const DEVICE_BASE_ADDRESS: u8 = 0b100_1000;
-
 struct Register;
 impl Register {
     const CONVERSION: u8 = 0x00;
diff --git a/src/types.rs b/src/types.rs
index 1ec4601..31b4cdb 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -162,56 +162,35 @@ pub enum FullScaleRange {
     Within0_256V,
 }
 
-/// Possible slave addresses
+/// A slave address.
+///
+/// See [Table 4 in the datasheet](https://www.ti.com/lit/ds/symlink/ads1115.pdf#%5B%7B%22num%22%3A716%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C0%2C602.2%2C0%5D).
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Ord, PartialOrd, Hash)]
 pub enum SlaveAddr {
+    /// Address when the ADDR pin is connected to GND. (default)
     #[default]
-    /// Default slave address
-    Default,
-    /// Alternative slave address using the provided values
-    /// for the last two bits (A1, A0)
-    Alternative(bool, bool),
+    Gnd,
+    /// Address when the ADDR pin is connected to VDD.
+    Vdd,
+    /// Address when the ADDR pin is connected to SDA.
+    ///
+    /// If SDA is used as the device address, hold the SDA line low for at
+    /// least 100 ns after the SCL line goes low to make sure the device
+    /// decodes the address correctly during I²C communication.
+    Sda,
+    /// Address when the ADDR pin is connected to SCL.
+    Scl,
 }
 
 impl SlaveAddr {
-    pub(crate) fn addr(self, default: u8) -> u8 {
+    pub(crate) const fn bits(self) -> u8 {
         match self {
-            SlaveAddr::Default => default,
-            SlaveAddr::Alternative(a1, a0) => default | ((a1 as u8) << 1) | a0 as u8,
+            Self::Gnd => 0b1001000,
+            Self::Vdd => 0b1001001,
+            Self::Sda => 0b1001010,
+            Self::Scl => 0b1001011,
         }
     }
-
-    /// Create `SlaveAddr` instance corresponding to the address
-    /// effective when connecting the pin `ADDR` to GND (0x48).
-    ///
-    /// See [Table 4 in the datasheet](https://www.ti.com/lit/ds/symlink/ads1115.pdf#%5B%7B%22num%22%3A716%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C0%2C602.2%2C0%5D).
-    pub fn new_gnd() -> Self {
-        SlaveAddr::default()
-    }
-
-    /// Create `SlaveAddr` instance corresponding to the address
-    /// effective when connecting the pin `ADDR` to VDD (0x49).
-    ///
-    /// See [Table 4 in the datasheet](https://www.ti.com/lit/ds/symlink/ads1115.pdf#%5B%7B%22num%22%3A716%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C0%2C602.2%2C0%5D).
-    pub fn new_vdd() -> Self {
-        SlaveAddr::Alternative(false, true)
-    }
-
-    /// Create `SlaveAddr` instance corresponding to the address
-    /// effective when connecting the pin `ADDR` to SDA (0x4A).
-    ///
-    /// See [Table 4 in the datasheet](https://www.ti.com/lit/ds/symlink/ads1115.pdf#%5B%7B%22num%22%3A716%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C0%2C602.2%2C0%5D).
-    pub fn new_sda() -> Self {
-        SlaveAddr::Alternative(true, false)
-    }
-
-    /// Create `SlaveAddr` instance corresponding to the address
-    /// effective when connecting the pin `ADDR` to SCL (0x4B).
-    ///
-    /// See [Table 4 in the datasheet](https://www.ti.com/lit/ds/symlink/ads1115.pdf#%5B%7B%22num%22%3A716%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2C0%2C602.2%2C0%5D).
-    pub fn new_scl() -> Self {
-        SlaveAddr::Alternative(true, true)
-    }
 }
 
 #[derive(Debug, Clone, PartialEq)]
@@ -267,29 +246,19 @@ pub trait DynamicOneShot: private::Sealed {
 
 #[cfg(test)]
 mod tests {
-    use crate::DEVICE_BASE_ADDRESS as ADDR;
     use crate::{FullScaleRange, SlaveAddr};
 
     #[test]
-    fn can_get_default_address() {
-        let addr = SlaveAddr::default();
-        assert_eq!(ADDR, addr.addr(ADDR));
-    }
-
-    #[test]
-    fn can_generate_alternative_addresses() {
-        assert_eq!(0b100_1000, SlaveAddr::Alternative(false, false).addr(ADDR));
-        assert_eq!(0b100_1001, SlaveAddr::Alternative(false, true).addr(ADDR));
-        assert_eq!(0b100_1010, SlaveAddr::Alternative(true, false).addr(ADDR));
-        assert_eq!(0b100_1011, SlaveAddr::Alternative(true, true).addr(ADDR));
+    fn slave_addr_default() {
+        assert_eq!(0b100_1000, SlaveAddr::default().bits());
     }
 
     #[test]
-    fn can_generate_alternative_addresses_using_helper_constructors() {
-        assert_eq!(0b100_1000, SlaveAddr::new_gnd().addr(ADDR));
-        assert_eq!(0b100_1001, SlaveAddr::new_vdd().addr(ADDR));
-        assert_eq!(0b100_1010, SlaveAddr::new_sda().addr(ADDR));
-        assert_eq!(0b100_1011, SlaveAddr::new_scl().addr(ADDR));
+    fn slave_addr_bits() {
+        assert_eq!(0b100_1000, SlaveAddr::Gnd.bits());
+        assert_eq!(0b100_1001, SlaveAddr::Vdd.bits());
+        assert_eq!(0b100_1010, SlaveAddr::Sda.bits());
+        assert_eq!(0b100_1011, SlaveAddr::Scl.bits());
     }
 
     #[test]