diff --git a/ds3231.hpp b/ds3231.hpp
new file mode 100644
index 0000000..62bf497
--- /dev/null
+++ b/ds3231.hpp
@@ -0,0 +1,130 @@
+#pragma once
+
+#include "../clock.hpp"
+
+#include "../i2c/i2c.hpp"
+#include "../type/type.hpp"
+
+#include "registers.hpp"
+
+namespace rtc {
+
+struct Date {
+	uint16_t year;
+	uint8_t month;
+	uint8_t day;
+};
+
+struct Time {
+	uint8_t hour;
+	uint8_t minute;
+	uint8_t second;
+};
+
+struct DateTime : Date, Time {
+};
+
+template <typename I2cDriver>
+class DS3231 {
+  public:
+	static constexpr auto I2C_ADDRESS = 0x68;
+
+	static constexpr auto TIME_REG_ADDR = 0x00;
+	static constexpr auto ALARM1_REG_ADDR = 0x07;
+	static constexpr auto ALARM2_REG_ADDR = 0x0B;
+	static constexpr auto CONTROL_REG_ADDR = 0x0E;
+	static constexpr auto CONTROL_STATUS_REG_ADDR = 0x0F;
+	static constexpr auto AGING_OFFSET_REG_ADDR = 0x10;
+	static constexpr auto TEMP_REG_ADDR = 0x11;
+
+	// Construction does not call init and is only available for convenience
+	DS3231() = default;
+
+	// Moving and copying ds3231 objects is not supported
+	DS3231(const DS3231 &) = delete;
+	DS3231(DS3231 &&) = delete;
+	DS3231 &operator=(const DS3231 &) = delete;
+	DS3231 &operator=(DS3231 &&) = delete;
+
+	static inline void init()
+	{
+		I2cDriver::init();
+	}
+
+	static auto getDate()
+	{
+		const auto timeReg = readRegister<TIME_REG_ADDR>();
+
+		Date date;
+		date.year = timeReg.getYear();
+		date.month = timeReg.getMonth();
+		date.day = timeReg.getDate();
+		return date;
+	}
+	static auto getTime()
+	{
+		const auto timeReg = readRegister<TIME_REG_ADDR>();
+
+		Time time;
+		time.hour = timeReg.getHours();
+		time.minute = timeReg.getMinutes();
+		time.second = timeReg.getSeconds();
+		return time;
+	}
+	static auto getDateTime()
+	{
+		const auto timeReg = readRegister<TIME_REG_ADDR>();
+
+		DateTime dateTime;
+		dateTime.year = timeReg.getYear();
+		dateTime.month = timeReg.getMonth();
+		dateTime.day = timeReg.getDate();
+		dateTime.hour = timeReg.getHours();
+		dateTime.minute = timeReg.getMinutes();
+		dateTime.second = timeReg.getSeconds();
+		return dateTime;
+	}
+
+	static void setDate(const Date &date) {}
+	static void setTime(const Time &time) {}
+	static void setDateTime(const DateTime &dateTime) {}
+
+  private:
+	template <uint8_t Address, typename Register>
+	static Register readRegisterHelper()
+	{
+		I2cDriver::template start<I2C_ADDRESS>(false);
+		I2cDriver::write(Address);
+		I2cDriver::stop();
+
+		Register reg;
+		I2cDriver::template start<I2C_ADDRESS>(true);
+		I2cDriver::template readBytes<sizeof(Register)>(reinterpret_cast<uint8_t *>(&reg));
+		I2cDriver::stop();
+		return reg;
+	}
+
+	template <uint8_t Address>
+	static auto readRegister()
+	{
+		if constexpr (Address == TIME_REG_ADDR) {
+			return readRegisterHelper<Address, detail::TimeReg>();
+		} else if constexpr (Address == ALARM1_REG_ADDR) {
+			return readRegisterHelper<Address, detail::Alarm1Reg>();
+		} else if constexpr (Address == ALARM2_REG_ADDR) {
+			return readRegisterHelper<Address, detail::Alarm2Reg>();
+		} else if constexpr (Address == CONTROL_REG_ADDR) {
+			return readRegisterHelper<Address, detail::ControlReg>();
+		} else if constexpr (Address == CONTROL_STATUS_REG_ADDR) {
+			return readRegisterHelper<Address, detail::ControlStatusReg>();
+		} else if constexpr (Address == AGING_OFFSET_REG_ADDR) {
+			return readRegisterHelper<Address, detail::AgingOffsetReg>();
+		} else if constexpr (Address == TEMP_REG_ADDR) {
+			return readRegisterHelper<Address, detail::TempReg>();
+		} else {
+			static_assert(type::always_false_v<decltype(Address)>, "Invalid register address");
+		}
+	}
+};
+
+} // namespace rtc
diff --git a/flags.hpp b/flags.hpp
new file mode 100644
index 0000000..12d58c8
--- /dev/null
+++ b/flags.hpp
@@ -0,0 +1,71 @@
+#pragma once
+
+namespace rtc {
+
+namespace detail {
+
+template <typename FlagsT>
+struct [[gnu::packed]] FlagsImpl
+{
+	static_assert(sizeof(FlagsT) == sizeof(uint8_t), "Must use uint8_t enum class flags");
+
+	uint8_t data;
+	using Flags = FlagsT;
+
+	FlagsImpl() : data(0) {}
+	FlagsImpl(const Flags &flag) : data(static_cast<uint8_t>(flag)) {}
+
+	FlagsImpl(const FlagsImpl &other) : data(other.data) {}
+	FlagsImpl(const FlagsImpl &&) = delete;
+
+	FlagsImpl &operator=(const FlagsImpl &rhs)
+	{
+		data = rhs.data;
+		return *this;
+	}
+	FlagsImpl &operator=(const FlagsImpl &&) = delete;
+
+	FlagsImpl &operator=(const FlagsT &rhs)
+	{
+		data = static_cast<uint8_t>(rhs);
+		return *this;
+	}
+
+	FlagsImpl &operator|=(const FlagsT &flag)
+	{
+		data |= static_cast<uint8_t>(flag);
+		return *this;
+	}
+
+	FlagsImpl &operator&=(const FlagsT &flag)
+	{
+		data &= static_cast<uint8_t>(flag);
+		return *this;
+	}
+
+	FlagsImpl &operator~()
+	{
+		data = ~data;
+		return *this;
+	}
+};
+
+template <typename FlagsT>
+FlagsT operator|(const FlagsT &lhs, const FlagsT &rhs)
+{
+	const auto lhsInt = static_cast<uint8_t>(lhs);
+	const auto rhsInt = static_cast<uint8_t>(rhs);
+	return static_cast<FlagsT>(lhsInt | rhsInt);
+}
+
+template <typename FlagsT>
+FlagsT operator&(const FlagsT &lhs, const FlagsT &rhs)
+{
+	const auto lhsInt = static_cast<uint8_t>(lhs);
+	const auto rhsInt = static_cast<uint8_t>(rhs);
+	return static_cast<FlagsT>(lhsInt & rhsInt);
+}
+
+} // namespace detail
+
+} // namespace rtc
diff --git a/registers.hpp b/registers.hpp
new file mode 100644
index 0000000..b1d83c8
--- /dev/null
+++ b/registers.hpp
@@ -0,0 +1,419 @@
+#pragma once
+
+#include <stdint.h>
+
+#include "flags.hpp"
+
+namespace rtc {
+
+namespace detail {
+
+//////////////////////////////////////////////////////////////////////////
+
+template <uint8_t Mask = 0xFF>
+static inline uint8_t toBcd(const uint8_t &data)
+{
+	return ((data / 10 * 16) + (data % 10)) & Mask;
+}
+
+template <uint8_t Mask = 0xFF>
+static inline uint8_t fromBcd(const uint8_t &data)
+{
+	const auto maskedData = data & Mask;
+	return ((maskedData / 16 * 10) + (maskedData % 16));
+}
+
+static inline uint8_t convertTo24Hour(const uint8_t &hoursReg)
+{
+	constexpr auto FLAG_12_HOUR = 6;
+	constexpr auto FLAG_PM = 5;
+
+	const bool time12HourFormat = (hoursReg >> FLAG_12_HOUR) & 1;
+
+	if (time12HourFormat) {
+		const auto pmFlag = (hoursReg >> FLAG_PM) & 1;
+		constexpr auto HOUR_12_MASK = 0b00011111;
+		const auto hour12 = fromBcd<HOUR_12_MASK>(hoursReg);
+		if (hour12 == 12 && !pmFlag)
+			return 0;
+		return hour12 + pmFlag ? 12 : 0;
+	} else // 24 hour format
+	{
+		constexpr auto HOUR_MASK = 0b00111111;
+		return fromBcd<HOUR_MASK>(hoursReg);
+	}
+}
+
+template <uint8_t Mask = 0b01111111>
+static inline uint8_t getMaskedBcd(const uint8_t &reg)
+{
+	return fromBcd<Mask>(reg);
+}
+
+template <uint8_t Mask = 0b01111111>
+static inline void setMaskedBcd(uint8_t &reg, const uint8_t &value)
+{
+	reg &= ~Mask;
+	reg |= toBcd<Mask>(value);
+}
+
+static inline bool getEncodedDay(uint8_t &value, const uint8_t &reg)
+{
+	constexpr auto DAY_FLAG = 6;
+	if ((reg >> DAY_FLAG) & 1) {
+		constexpr auto DAY_MASK = 0b00001111;
+		value = reg & DAY_MASK;
+		return true;
+	}
+
+	return false;
+}
+
+static inline bool getEncodedDate(uint8_t &value, const uint8_t &reg)
+{
+	constexpr auto DAY_FLAG = 6;
+	if (!((reg >> DAY_FLAG) & 1)) {
+		value = getMaskedBcd<0b00111111>(reg);
+		return true;
+	}
+
+	return false;
+}
+
+static inline void setEncodedDay(uint8_t &reg, const uint8_t &value)
+{
+	constexpr auto DAY_MASK = 0b11110000;
+	reg &= DAY_MASK;
+	reg |= value & DAY_MASK;
+	constexpr auto DAY_FLAG = 6;
+	reg |= (1 << DAY_FLAG);
+}
+
+static inline void setEncodedDate(uint8_t &reg, const uint8_t &value)
+{
+	setMaskedBcd<0b00111111>(reg, value);
+	constexpr auto DAY_FLAG = 6;
+	reg &= ~(1 << DAY_FLAG);
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+struct [[gnu::packed]] TimeReg
+{
+	uint8_t seconds;
+	uint8_t minutes;
+	uint8_t hours;
+	uint8_t day;
+	uint8_t date;
+	uint8_t month_century;
+	uint8_t year;
+
+	//////////////////////////////////////////////////////////////////////////
+
+	inline uint8_t getSeconds() const
+	{
+		return getMaskedBcd(seconds);
+	}
+	inline uint8_t getMinutes() const
+	{
+		return getMaskedBcd(minutes);
+	}
+	inline uint8_t getHours() const
+	{
+		return convertTo24Hour(hours);
+	}
+	inline uint8_t getDay() const
+	{
+		return getMaskedBcd<0b00000111>(day);
+	}
+	inline uint8_t getDate() const
+	{
+		return getMaskedBcd<0b00111111>(date);
+	}
+	inline uint8_t getMonth() const
+	{
+		return getMaskedBcd<0b00011111>(month_century);
+	}
+	inline bool getCentury() const
+	{
+		constexpr auto CENTURY_FLAG = 7;
+		return (month_century >> CENTURY_FLAG) & 1;
+	}
+	inline uint16_t getYear() const
+	{
+		return 2000 + fromBcd(year);
+	}
+
+	//////////////////////////////////////////////////////////////////////////
+
+	inline void setSeconds(uint8_t seconds)
+	{
+		setMaskedBcd(this->seconds, seconds);
+	}
+	inline void setMinutes(uint8_t minutes)
+	{
+		setMaskedBcd(this->minutes, minutes);
+	}
+	inline void setHours(uint8_t hours)
+	{
+		setMaskedBcd(this->hours, hours);
+	}
+	inline void setDay(uint8_t day)
+	{
+		this->day = day & 0b111;
+	}
+	inline void setDate(uint8_t date)
+	{
+		setMaskedBcd<0b00111111>(this->date, date);
+	}
+	inline void setMonth(uint8_t month)
+	{
+		setMaskedBcd<0b00011111>(month_century, month);
+	}
+	inline void setCentury(bool century)
+	{
+		constexpr auto CENTURY_POS = 7;
+		month_century &= ~(1 << CENTURY_POS);
+		month_century |= (century << CENTURY_POS);
+	}
+	inline void setYear(uint16_t year)
+	{
+		year = year % 100;
+		this->year = toBcd(year);
+	}
+};
+
+static_assert(sizeof(TimeReg) == 7, "Invalid time register size");
+
+//////////////////////////////////////////////////////////////////////////
+
+struct [[gnu::packed]] Alarm1Reg
+{
+	uint8_t seconds;
+	uint8_t minutes;
+	uint8_t hours;
+	uint8_t day_date;
+
+	enum class AlarmRate {
+		ONCE_PER_S = 0b1111,
+		WHEN_S_MATCH = 0b1110,
+		WHEN_M_S_MATCH = 0b1100,
+		WHEN_H_M_S_MATCH = 0b1000,
+		WHEN_DATE_H_M_S_MATCH = 0b00000,
+		WHEN_DAY_H_N_S_MATCH = 0b10000,
+	};
+
+	//////////////////////////////////////////////////////////////////////////
+
+	inline uint8_t getSeconds() const
+	{
+		return getMaskedBcd(seconds);
+	}
+	inline uint8_t getMinutes() const
+	{
+		return getMaskedBcd(minutes);
+	}
+	inline uint8_t getHours() const
+	{
+		return convertTo24Hour(hours);
+	}
+	inline bool getDay(uint8_t & day) const
+	{
+		return getEncodedDay(day, day_date);
+	}
+	inline bool getDate(uint8_t & date) const
+	{
+		return getEncodedDate(date, day_date);
+	}
+	inline AlarmRate getAlarmRate() const
+	{
+		constexpr auto M_FLAG = 7;
+		const auto m1 = (seconds >> M_FLAG) & 1;
+		const auto m2 = (minutes >> M_FLAG) & 1;
+		const auto m3 = (hours >> M_FLAG) & 1;
+		const auto m4 = (day_date >> M_FLAG) & 1;
+		const auto m = (m4 << 3) | (m3 << 2) | (m2 << 1) | (m1 << 0);
+		if (m == 0) {
+			constexpr auto DAY_FLAG = 6;
+			const auto dayFormat = ((day_date >> DAY_FLAG) & 1) << 4;
+			return static_cast<AlarmRate>(dayFormat);
+		}
+		return static_cast<AlarmRate>(m);
+	}
+
+	//////////////////////////////////////////////////////////////////////////
+
+	inline void setSeconds(uint8_t seconds)
+	{
+		setMaskedBcd(this->seconds, seconds);
+	}
+	inline void setMinutes(uint8_t minutes)
+	{
+		setMaskedBcd(this->minutes, minutes);
+	}
+	inline void setHours(uint8_t hours)
+	{
+		setMaskedBcd(this->hours, hours);
+	}
+	inline void setDay(uint8_t day)
+	{
+		setEncodedDay(day_date, day);
+	}
+	inline void setDate(uint8_t date)
+	{
+		setEncodedDate(day_date, date);
+	}
+	inline void setAlarmRate(const AlarmRate &alarmRate)
+	{
+		const auto alarmRateFlags = static_cast<uint8_t>(alarmRate);
+		constexpr auto M_FLAG = 7;
+		seconds &= ~(1 << M_FLAG);
+		seconds |= (alarmRateFlags & 1) << M_FLAG;
+		minutes &= ~(1 << M_FLAG);
+		minutes |= ((alarmRateFlags >> 1) & 1) << M_FLAG;
+		hours &= ~(1 << M_FLAG);
+		hours |= ((alarmRateFlags >> 2) & 1) << M_FLAG;
+		day_date &= ~(1 << M_FLAG);
+		day_date |= ((alarmRateFlags >> 3) & 1) << M_FLAG;
+	}
+};
+
+static_assert(sizeof(Alarm1Reg) == 4, "Invalid alarm1 register size");
+
+//////////////////////////////////////////////////////////////////////////
+
+struct [[gnu::packed]] Alarm2Reg
+{
+	uint8_t minutes;
+	uint8_t hours;
+	uint8_t day_date;
+
+	enum class AlarmRate {
+		ONCE_PER_M = 0b111,
+		WHEN_M_MATCH = 0b110,
+		WHEN_H_M_MATCH = 0b100,
+		WHEN_DATE_H_M_MATCH = 0b0000,
+		WHEN_DAY_H_N_MATCH = 0b1000,
+	};
+
+	//////////////////////////////////////////////////////////////////////////
+
+	inline uint8_t getMinutes() const
+	{
+		return getMaskedBcd(minutes);
+	}
+	inline uint8_t getHours() const
+	{
+		return convertTo24Hour(hours);
+	}
+	inline bool getDay(uint8_t & day) const
+	{
+		return getEncodedDay(day, day_date);
+	}
+	inline bool getDate(uint8_t & date) const
+	{
+		return getEncodedDate(date, day_date);
+	}
+	inline AlarmRate getAlarmRate() const
+	{
+		constexpr auto M_FLAG = 7;
+		const auto m2 = (minutes >> M_FLAG) & 1;
+		const auto m3 = (hours >> M_FLAG) & 1;
+		const auto m4 = (day_date >> M_FLAG) & 1;
+		const auto m = (m4 << 2) | (m3 << 1) | (m2 << 0);
+		if (m == 0) {
+			constexpr auto DAY_FLAG = 6;
+			const auto dayFormat = ((day_date >> DAY_FLAG) & 1) << 3;
+			return static_cast<AlarmRate>(dayFormat);
+		}
+		return static_cast<AlarmRate>(m);
+	}
+
+	//////////////////////////////////////////////////////////////////////////
+
+	inline void setMinutes(uint8_t minutes)
+	{
+		setMaskedBcd(this->minutes, minutes);
+	}
+	inline void setHours(uint8_t hours)
+	{
+		setMaskedBcd(this->hours, hours);
+	}
+	inline void setDay(uint8_t day)
+	{
+		setEncodedDay(day_date, day);
+	}
+	inline void setDate(uint8_t date)
+	{
+		setEncodedDate(day_date, date);
+	}
+	inline void setAlarmRate(const AlarmRate &alarmRate)
+	{
+		const auto alarmRateFlags = static_cast<uint8_t>(alarmRate);
+		constexpr auto M_FLAG = 7;
+		minutes &= ~(1 << M_FLAG);
+		minutes |= (alarmRateFlags & 1) << M_FLAG;
+		hours &= ~(1 << M_FLAG);
+		hours |= ((alarmRateFlags >> 1) & 1) << M_FLAG;
+		day_date &= ~(1 << M_FLAG);
+		day_date |= ((alarmRateFlags >> 2) & 1) << M_FLAG;
+	}
+};
+
+static_assert(sizeof(Alarm2Reg) == 3, "Invalid alarm2 register size");
+
+//////////////////////////////////////////////////////////////////////////
+
+enum class ControlRegFlags : uint8_t {
+	N_EOSC = 1 << 7,
+	BBSQW = 1 << 6,
+	CONV = 1 << 5,
+	RS2 = 1 << 4,
+	RS1 = 1 << 3,
+	INTCN = 1 << 2,
+	A2IE = 1 << 1,
+	A1IE = 1 << 0,
+};
+
+struct [[gnu::packed]] ControlReg : FlagsImpl<ControlRegFlags>{};
+
+static_assert(sizeof(ControlReg) == 1, "Invalid control register size");
+
+//////////////////////////////////////////////////////////////////////////
+
+enum class ControlStatusRegFlags : uint8_t {
+	OSF = 1 << 7,
+	EN32KHZ = 1 << 3,
+	BSY = 1 << 2,
+	A2F = 1 << 1,
+	A1F = 1 << 0,
+};
+
+struct [[gnu::packed]] ControlStatusReg : FlagsImpl<ControlStatusRegFlags>{};
+
+static_assert(sizeof(ControlStatusReg) == 1, "Invalid control/status register size");
+
+//////////////////////////////////////////////////////////////////////////
+
+struct [[gnu::packed]] AgingOffsetReg
+{
+	uint8_t data;
+};
+
+static_assert(sizeof(AgingOffsetReg) == 1, "Invalid aging offset register size");
+
+//////////////////////////////////////////////////////////////////////////
+
+struct [[gnu::packed]] TempReg
+{
+	uint8_t msb_temp;
+	uint8_t lsb_temp;
+};
+
+static_assert(sizeof(TempReg) == 2, "Invalid temperature register size");
+
+//////////////////////////////////////////////////////////////////////////
+
+} // namespace detail
+
+} // namespace rtc