Generate error when century bit is set in functions already reading the century bit

* Add defmt support behind the feature flag defmt.

* Update rtcc dependency

* Updated changelog to reflect defmt support.

* Update CHANGELOG.md

* Update CHANGELOG.md

---------

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

CHANGELOG.md

@@ -8,6 +8,16 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 <!-- next-header -->
 ## [Unreleased] - ReleaseDate
 
+## [0.7.0] - 2025-10-11
+
+### Added
+
+- Added `defmt` support behind a feature flag.
+
+### Changed
+
+- Updated `rtcc` to version  0.4.0, which has `defmt` support.
+
 ## [0.6.0] - 2025-01-02
 
 ### Changed
@@ -91,7 +101,8 @@ this CHANGELOG.
 [`rtcc`]: https://crates.io/crates/rtcc
 
 <!-- next-url -->
-[Unreleased]: https://github.com/eldruin/ds323x-rs/compare/v0.6.0...HEAD
+[Unreleased]: https://github.com/eldruin/ds323x-rs/compare/v0.7.0...HEAD
+[0.7.0]: https://github.com/eldruin/ds323x-rs/compare/v0.6.0...v0.7.0
 [0.6.0]: https://github.com/eldruin/ds323x-rs/compare/v0.5.1...v0.6.0
 [0.5.1]: https://github.com/eldruin/ds323x-rs/compare/v0.5.0...v0.5.1
 [0.5.0]: https://github.com/eldruin/ds323x-rs/compare/v0.4.0...v0.5.0
@@ -99,4 +110,4 @@ this CHANGELOG.
 [0.3.2]: https://github.com/eldruin/ds323x-rs/compare/v0.3.1...v0.3.2
 [0.3.1]: https://github.com/eldruin/ds323x-rs/compare/v0.3.0...v0.3.1
 [0.3.0]: https://github.com/eldruin/ds323x-rs/compare/v0.2.0...v0.3.0
-[0.2.0]: https://github.com/eldruin/ds323x-rs/compare/v0.1.0...v0.2.0
+[0.2.0]: https://github.com/eldruin/ds323x-rs/compare/v0.1.0...v0.2.0

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ds323x"
-version = "0.6.0"
+version = "0.7.0"
 authors = ["Diego Barrios Romero <eldruin@gmail.com>"]
 repository = "https://github.com/eldruin/ds323x-rs"
 license = "MIT OR Apache-2.0"
@@ -20,9 +20,13 @@ include = [
 ]
 edition = "2018"
 
+[features]
+defmt = ["dep:defmt", "rtcc/defmt"]
+
 [dependencies]
 embedded-hal = "1.0.0"
-rtcc = "0.3"
+rtcc = "0.4"
+defmt = { version = "1.0.1", optional = true }
 
 [dev-dependencies]
 embedded-hal-mock = { version = "0.11.1", features = ["eh1"] }

src/ds323x/alarms.rs

@@ -15,6 +15,7 @@ use crate::{
 /// - Second, minute and hour: 0
 /// - Day: 1
 #[derive(Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct DayAlarm1 {
     /// Day of the month [1-31]
     pub day: u8,
@@ -34,6 +35,7 @@ pub struct DayAlarm1 {
 /// - Second, minute and hour: 0
 /// - Weekday: 1
 #[derive(Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct WeekdayAlarm1 {
     /// Weekday [1-7]
     pub weekday: u8,
@@ -47,6 +49,7 @@ pub struct WeekdayAlarm1 {
 
 /// Alarm1 trigger rate
 #[derive(Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Alarm1Matching {
     /// Alarm once per second.
     OncePerSecond,
@@ -68,6 +71,7 @@ pub enum Alarm1Matching {
 /// - Minute and hour: 0
 /// - Day: 1
 #[derive(Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct DayAlarm2 {
     /// Day of month [1-31]
     pub day: u8,
@@ -85,6 +89,7 @@ pub struct DayAlarm2 {
 /// - Minute and hour: 0
 /// - Weekday: 1
 #[derive(Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct WeekdayAlarm2 {
     /// Weekday [1-7]
     pub weekday: u8,
@@ -96,6 +101,7 @@ pub struct WeekdayAlarm2 {
 
 /// Alarm2 trigger rate
 #[derive(Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Alarm2Matching {
     /// Alarm once per minute. (00 seconds of every minute)
     OncePerMinute,

src/ds323x/datetime.rs

@@ -19,11 +19,13 @@ where
         let mut data = [0; 8];
         self.iface.read_data(&mut data)?;
 
-        let year = year_from_registers(
-            data[Register::MONTH as usize + 1],
-            data[Register::YEAR as usize + 1],
-        );
-        let month = packed_bcd_to_decimal(data[Register::MONTH as usize + 1] & !BitFlags::CENTURY);
+        let century = data[Register::MONTH as usize + 1] & BitFlags::CENTURY;
+        if century != 0 {
+            return Err(Error::InvalidDeviceCentury);
+        }
+
+        let year = 2000 + (packed_bcd_to_decimal(data[Register::YEAR as usize + 1]) as u16);
+        let month = packed_bcd_to_decimal(data[Register::MONTH as usize + 1]);
         let day = packed_bcd_to_decimal(data[Register::DOM as usize + 1]);
         let hour = hours_from_register(data[Register::HOURS as usize + 1]);
         let minute = packed_bcd_to_decimal(data[Register::MINUTES as usize + 1]);
@@ -36,10 +38,9 @@ where
     }
 
     fn set_datetime(&mut self, datetime: &NaiveDateTime) -> Result<(), Self::Error> {
-        if datetime.year() < 2000 || datetime.year() > 2100 {
+        if !(2000..=2099).contains(&datetime.year()) {
             return Err(Error::InvalidInputData);
         }
-        let (month, year) = month_year_to_registers(datetime.month() as u8, datetime.year() as u16);
         let mut payload = [
             Register::SECONDS,
             decimal_to_packed_bcd(datetime.second() as u8),
@@ -47,8 +48,8 @@ where
             hours_to_register(Hours::H24(datetime.hour() as u8))?,
             datetime.weekday().number_from_sunday() as u8,
             decimal_to_packed_bcd(datetime.day() as u8),
-            month,
-            year,
+            decimal_to_packed_bcd(datetime.month() as u8),
+            decimal_to_packed_bcd((datetime.year() - 2000) as u8),
         ];
         self.iface.write_data(&mut payload)
     }
@@ -92,15 +93,28 @@ where
 
     fn month(&mut self) -> Result<u8, Self::Error> {
         let data = self.iface.read_register(Register::MONTH)?;
-        let value = data & !BitFlags::CENTURY;
-        Ok(packed_bcd_to_decimal(value))
+
+        let century = data & BitFlags::CENTURY;
+        if century != 0 {
+            return Err(Error::InvalidDeviceCentury);
+        }
+
+        Ok(packed_bcd_to_decimal(data))
     }
 
     fn year(&mut self) -> Result<u16, Self::Error> {
         let mut data = [0; 3];
         data[0] = Register::MONTH;
         self.iface.read_data(&mut data)?;
-        Ok(year_from_registers(data[1], data[2]))
+
+        let century = data[1] & BitFlags::CENTURY;
+        if century != 0 {
+            return Err(Error::InvalidDeviceCentury);
+        }
+
+        let year = 2000 + (packed_bcd_to_decimal(data[2]) as u16);
+
+        Ok(year)
     }
 
     fn date(&mut self) -> Result<NaiveDate, Self::Error> {
@@ -109,12 +123,15 @@ where
         self.iface.read_data(&mut data)?;
 
         let offset = Register::DOM as usize;
-        let year = year_from_registers(
-            data[Register::MONTH as usize + 1 - offset],
-            data[Register::YEAR as usize + 1 - offset],
-        );
-        let month =
-            packed_bcd_to_decimal(data[Register::MONTH as usize + 1 - offset] & !BitFlags::CENTURY);
+
+        let century = data[Register::MONTH as usize + 1 - offset] & BitFlags::CENTURY;
+        if century != 0 {
+            return Err(Error::InvalidDeviceCentury);
+        }
+
+        let year =
+            2000 + (packed_bcd_to_decimal(data[Register::YEAR as usize + 1 - offset]) as u16);
+        let month = packed_bcd_to_decimal(data[Register::MONTH as usize + 1 - offset]);
         let day = packed_bcd_to_decimal(data[Register::DOM as usize + 1 - offset]);
         let date = NaiveDate::from_ymd_opt(year.into(), month.into(), day.into());
         some_or_invalid_error(date)
@@ -174,39 +191,30 @@ where
     }
 
     fn set_year(&mut self, year: u16) -> Result<(), Self::Error> {
-        if !(2000..=2100).contains(&year) {
+        if !(2000..=2099).contains(&year) {
             return Err(Error::InvalidInputData);
         }
         let data = self.iface.read_register(Register::MONTH)?;
         let month_bcd = data & !BitFlags::CENTURY;
-        if year > 2099 {
-            let mut data = [
-                Register::MONTH,
-                BitFlags::CENTURY | month_bcd,
-                decimal_to_packed_bcd((year - 2100) as u8),
-            ];
-            self.iface.write_data(&mut data)
-        } else {
-            let mut data = [
-                Register::MONTH,
-                month_bcd,
-                decimal_to_packed_bcd((year - 2000) as u8),
-            ];
-            self.iface.write_data(&mut data)
-        }
+
+        let mut data = [
+            Register::MONTH,
+            month_bcd,
+            decimal_to_packed_bcd((year - 2000) as u8),
+        ];
+        self.iface.write_data(&mut data)
     }
 
     fn set_date(&mut self, date: &rtcc::NaiveDate) -> Result<(), Self::Error> {
-        if date.year() < 2000 || date.year() > 2100 {
+        if !(2000..=2099).contains(&date.year()) {
             return Err(Error::InvalidInputData);
         }
-        let (month, year) = month_year_to_registers(date.month() as u8, date.year() as u16);
         let mut payload = [
             Register::DOW,
             date.weekday().number_from_sunday() as u8,
             decimal_to_packed_bcd(date.day() as u8),
-            month,
-            year,
+            decimal_to_packed_bcd(date.month() as u8),
+            decimal_to_packed_bcd((date.year() - 2000) as u8),
         ];
         self.iface.write_data(&mut payload)
     }
@@ -241,28 +249,6 @@ fn hours_from_register(data: u8) -> Hours {
     }
 }
 
-fn year_from_registers(month: u8, year: u8) -> u16 {
-    let century = month & BitFlags::CENTURY;
-    let year = packed_bcd_to_decimal(year);
-    if century != 0 {
-        2100 + u16::from(year)
-    } else {
-        2000 + u16::from(year)
-    }
-}
-
-fn month_year_to_registers(month: u8, year: u16) -> (u8, u8) {
-    if year > 2099 {
-        let month = BitFlags::CENTURY | decimal_to_packed_bcd(month);
-        (month, decimal_to_packed_bcd((year - 2100) as u8))
-    } else {
-        (
-            decimal_to_packed_bcd(month),
-            decimal_to_packed_bcd((year - 2000) as u8),
-        )
-    }
-}
-
 fn is_24h_format(hours_data: u8) -> bool {
     hours_data & BitFlags::H24_H12 == 0
 }

src/interface.rs

@@ -5,12 +5,14 @@ use embedded_hal::{i2c, spi};
 
 /// I2C interface
 #[derive(Debug, Default)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct I2cInterface<I2C> {
     pub(crate) i2c: I2C,
 }
 
 /// SPI interface
 #[derive(Debug, Default)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct SpiInterface<SPI> {
     pub(crate) spi: SPI,
 }

src/lib.rs

@@ -377,6 +377,7 @@ pub const SPI_MODE_3: Mode = MODE_3;
 
 /// All possible errors in this crate
 #[derive(Debug)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum Error<E> {
     /// I²C/SPI bus error
     Comm(E),
@@ -387,10 +388,16 @@ pub enum Error<E> {
     /// It was not possible to read a valid date and/or time.
     /// The device is probably missing initialization.
     InvalidDeviceState,
+    /// Device century is not the 20th century.
+    ///
+    /// The device does not produce valid dates for centuries
+    /// other than the 20th century.
+    InvalidDeviceCentury,
 }
 
 /// Square-wave output frequency
 #[derive(Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum SqWFreq {
     /// 1 Hz (default)
     _1Hz,
@@ -406,6 +413,7 @@ pub enum SqWFreq {
 ///
 /// This is only available on the DS3232 and DS3234 devices.
 #[derive(Debug, Clone, Copy, PartialEq)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub enum TempConvRate {
     /// Once every 64 seconds (default)
     _64s,
@@ -478,6 +486,7 @@ pub mod ic {
 
 /// DS3231, DS3232 and DS3234 RTC driver
 #[derive(Debug, Default)]
+#[cfg_attr(feature = "defmt", derive(defmt::Format))]
 pub struct Ds323x<DI, IC> {
     iface: DI,
     control: u8,

tests/common/mod.rs

@@ -57,21 +57,6 @@ impl BitFlags {
     pub const WEEKDAY: u8 = 0b0100_0000;
 }
 
-pub struct DummyOutputPin;
-
-impl embedded_hal::digital::OutputPin for DummyOutputPin {
-    fn set_low(&mut self) -> Result<(), Self::Error> {
-        Ok(())
-    }
-    fn set_high(&mut self) -> Result<(), Self::Error> {
-        Ok(())
-    }
-}
-
-impl embedded_hal::digital::ErrorType for DummyOutputPin {
-    type Error = embedded_hal::digital::ErrorKind;
-}
-
 pub fn new_ds3231(
     transactions: &[I2cTrans],
 ) -> Ds323x<interface::I2cInterface<I2cMock>, ic::DS3231> {

tests/datetime.rs

@@ -185,12 +185,6 @@ mod month {
     get_param_test!(get, month, MONTH, 1, 1);
     read_set_param_test!(set, set_month, MONTH, 12, 0b0000_0010, 0b0001_0010);
     set_invalid_param_range_test!(invalid, set_month, 0, 13);
-
-    mod keeps_century {
-        use super::*;
-        get_param_test!(get, month, MONTH, 12, 0b1001_0010);
-        read_set_param_test!(set, set_month, MONTH, 12, 0b1000_0010, 0b1001_0010);
-    }
 }
 
 mod year {
@@ -206,18 +200,7 @@ mod year {
         0b1001_1001
     );
 
-    get_param_read_array_test!(century1_get, year, 2100, MONTH, [0b1000_0000, 0], [0, 0]);
-    read_set_param_write_two_test!(
-        century1_set,
-        set_year,
-        2100,
-        MONTH,
-        0b0001_0010,
-        0b1001_0010,
-        0
-    );
-
-    set_invalid_param_range_test!(invalid, set_year, 1999, 2101);
+    set_invalid_param_range_test!(invalid, set_year, 1999, 2100);
 }
 
 macro_rules! invalid_dt_test {
@@ -233,7 +216,7 @@ macro_rules! invalid_dt_test {
             }
             #[test]
             fn datetime_too_big() {
-                let dt = new_datetime(2101, 1, 2, 3, 4, 5);
+                let dt = new_datetime(2100, 1, 2, 3, 4, 5);
                 let mut dev = $create_method(&[]);
                 assert_invalid_input_data!(dev.set_datetime(&dt));
                 $destroy_method(dev);
@@ -247,7 +230,7 @@ macro_rules! invalid_dt_test {
             }
             #[test]
             fn date_too_big() {
-                let d = new_date(2101, 1, 2);
+                let d = new_date(2100, 1, 2);
                 let mut dev = $create_method(&[]);
                 assert_invalid_input_data!(dev.set_date(&d));
                 $destroy_method(dev);
@@ -339,17 +322,6 @@ macro_rules! dt_test {
                 $destroy_method(dev);
             }
 
-            #[test]
-            fn set_date_century() {
-                let d = new_date(2100, 8, 13);
-                let mut dev = $create_method(&$mac_trans_write!(
-                    DOW,
-                    [0b0000_0110, 0b0001_0011, 0b1000_1000, 0]
-                ));
-                dev.set_date(&d).unwrap();
-                $destroy_method(dev);
-            }
-
             #[test]
             fn get_time() {
                 let t = NaiveTime::from_hms_opt(23, 59, 58).unwrap();