Add get alarm helper to reduce code duplication

alarms.hpp

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <stdint.h>
+
+namespace rtc {
+
+enum class Alarm1Rate : uint8_t {
+	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,
+};
+
+enum class Alarm2Rate : uint8_t {
+	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,
+};
+
+} // namespace rtc

ds3231.hpp

@@ -0,0 +1,392 @@
+#pragma once
+
+#include "../clock.hpp"
+
+#include <stddef.h>
+
+#include "../i2c/i2c.hpp"
+#include "../util/type.hpp"
+
+#include "registers.hpp"
+
+namespace rtc {
+
+struct Date {
+	uint16_t year;
+	uint8_t month;
+	uint8_t day;
+
+	inline bool operator==(const Date &rhs) const
+	{
+		if (day != rhs.day)
+			return false;
+		if (month != rhs.month)
+			return false;
+		if (year != rhs.year)
+			return false;
+		return true;
+	}
+
+	inline bool operator!=(const Date &rhs)
+	{
+		return !(*this == rhs);
+	}
+};
+
+struct Time {
+	uint8_t hour;
+	uint8_t minute;
+	uint8_t second;
+
+	inline bool operator==(const Time &rhs) const
+	{
+		if (second != rhs.second)
+			return false;
+		if (minute != rhs.minute)
+			return false;
+		if (hour != rhs.hour)
+			return false;
+		return true;
+	}
+
+	inline bool operator!=(const Time &rhs)
+	{
+		return !(*this == rhs);
+	}
+};
+
+struct DateTime : Date, Time {
+	inline bool operator==(const DateTime &rhs) const
+	{
+		if (second != rhs.second)
+			return false;
+		if (minute != rhs.minute)
+			return false;
+		if (hour != rhs.hour)
+			return false;
+		if (day != rhs.day)
+			return false;
+		if (month != rhs.month)
+			return false;
+		if (year != rhs.year)
+			return false;
+		return true;
+	}
+
+	inline bool operator!=(const DateTime &rhs)
+	{
+		return !(*this == rhs);
+	}
+};
+
+template <typename I2cDriver, bool SetDayOfWeek = true>
+class DS3231 {
+	using i2c_t = i2c::I2c<I2cDriver>;
+
+  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()
+	{
+		i2c_t::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 DateTime getAlarm1()
+	{
+		return getAlarmHelper<ALARM1_REG_ADDR>();
+	}
+	static DateTime getAlarm2()
+	{
+		return getAlarmHelper<ALARM2_REG_ADDR>();
+	}
+
+	static void setDate(const Date &date)
+	{
+		detail::TimeReg timeReg;
+		timeReg.setYear(date.year);
+		timeReg.setMonth(date.month);
+		timeReg.setDate(date.day);
+		if constexpr (SetDayOfWeek)
+			timeReg.setDay(calcDayOfWeek(date.year, date.month, date.day) + 1);
+
+		constexpr auto DATE_START_OFFSET = offsetof(detail::TimeReg, day);
+		constexpr auto DATE_END_OFFSET = offsetof(detail::TimeReg, year);
+
+		writePartialRegister<DATE_START_OFFSET, DATE_END_OFFSET>(timeReg);
+	}
+	static void setTime(const Time &time)
+	{
+		detail::TimeReg timeReg;
+		timeReg.setHours(time.hour);
+		timeReg.setMinutes(time.minute);
+		timeReg.setSeconds(time.second);
+
+		constexpr auto TIME_START_OFFSET = offsetof(detail::TimeReg, seconds);
+		constexpr auto TIME_END_OFFSET = offsetof(detail::TimeReg, hours);
+
+		writePartialRegister<TIME_START_OFFSET, TIME_END_OFFSET>(timeReg);
+	}
+	static void setDateTime(const DateTime &dateTime)
+	{
+		detail::TimeReg timeReg;
+		timeReg.setYear(dateTime.year);
+		timeReg.setMonth(dateTime.month);
+		timeReg.setDate(dateTime.day);
+		if constexpr (SetDayOfWeek)
+			timeReg.setDay(calcDayOfWeek(dateTime.year, dateTime.month, dateTime.day) + 1);
+
+		timeReg.setHours(dateTime.hour);
+		timeReg.setMinutes(dateTime.minute);
+		timeReg.setSeconds(dateTime.second);
+
+		constexpr auto START_OFFSET = offsetof(detail::TimeReg, seconds);
+		constexpr auto END_OFFSET = offsetof(detail::TimeReg, year);
+
+		writePartialRegister<START_OFFSET, END_OFFSET>(timeReg);
+	}
+
+	static void setAlarm1(const DateTime &alarmTime, const Alarm1Rate &alarmRate, bool enableInterrupt = true)
+	{
+		setAlarmHelper(alarmTime, alarmRate);
+		if (enableInterrupt)
+			enableInterruptHelper<detail::ControlRegFlags::A1IE>();
+	}
+	static void setAlarm2(const DateTime &alarmTime, const Alarm2Rate &alarmRate, bool enableInterrupt = true)
+	{
+		setAlarmHelper(alarmTime, alarmRate);
+		if (enableInterrupt)
+			enableInterruptHelper<detail::ControlRegFlags::A2IE>();
+	}
+
+	static bool checkAlarm1()
+	{
+		return checkAlarmHelper<detail::ControlStatusRegFlags::A1F>();
+	}
+	static bool checkAlarm2()
+	{
+		return checkAlarmHelper<detail::ControlStatusRegFlags::A2F>();
+	}
+
+	static void clearAlarm1()
+	{
+		clearAlarmHelper<detail::ControlStatusRegFlags::A1F>();
+	}
+	static void clearAlarm2()
+	{
+		clearAlarmHelper<detail::ControlStatusRegFlags::A2F>();
+	}
+
+  private:
+	template <uint8_t Address, typename Register>
+	static Register readRegisterHelper()
+	{
+		i2c_t::template start<I2C_ADDRESS>(false);
+		i2c_t::write(Address);
+		i2c_t::stop();
+
+		Register reg;
+		i2c_t::template start<I2C_ADDRESS>(true);
+		i2c_t::template readBytes<sizeof(Register)>(reinterpret_cast<uint8_t *>(&reg));
+		i2c_t::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(util::always_false_v<decltype(Address)>, "Invalid register address");
+		}
+	}
+
+	template <uint8_t StartOffset, uint8_t EndOffset, typename Register>
+	static void writePartialRegister(const Register &reg)
+	{
+		constexpr auto getRegisterAddress = []() {
+			if constexpr (util::is_same_v<Register, detail::TimeReg>) {
+				return TIME_REG_ADDR;
+			} else if constexpr (util::is_same_v<Register, detail::Alarm1Reg>) {
+				return ALARM1_REG_ADDR;
+			} else if constexpr (util::is_same_v<Register, detail::Alarm2Reg>) {
+				return ALARM2_REG_ADDR;
+			} else if constexpr (util::is_same_v<Register, detail::ControlReg>) {
+				return CONTROL_REG_ADDR;
+			} else if constexpr (util::is_same_v<Register, detail::ControlStatusReg>) {
+				return CONTROL_STATUS_REG_ADDR;
+			} else if constexpr (util::is_same_v<Register, detail::AgingOffsetReg>) {
+				return AGING_OFFSET_REG_ADDR;
+			} else if constexpr (util::is_same_v<Register, detail::TempReg>) {
+				return TEMP_REG_ADDR;
+			} else {
+				static_assert(util::always_false_v<Register>, "Invalid register type");
+			}
+		};
+
+		constexpr auto ADDRESS = getRegisterAddress();
+
+		static_assert(StartOffset <= EndOffset, "Invalid offset range");
+		static_assert(StartOffset < sizeof(Register), "Start offset out of bounds");
+		static_assert(EndOffset < sizeof(Register), "End offset out of bounds");
+
+		constexpr auto WRITE_SIZE = EndOffset + 1 - StartOffset;
+		static_assert(StartOffset + WRITE_SIZE <= sizeof(Register), "Writing out of bounds");
+
+		i2c_t::template start<I2C_ADDRESS>(false);
+		i2c_t::write(ADDRESS + StartOffset);
+		i2c_t::template writeBytes<WRITE_SIZE>(reinterpret_cast<const uint8_t *>(&reg) + StartOffset);
+		i2c_t::stop();
+	}
+
+	template <typename Register>
+	static void writeRegister(const Register &reg)
+	{
+		writePartialRegister<0, sizeof(Register) - 1>(reg);
+	}
+
+	template <uint8_t Address>
+	static inline auto getAlarmHelper()
+	{
+		constexpr auto IsAlarm1 = Address == ALARM1_REG_ADDR;
+		static_assert(IsAlarm1 || Address == ALARM2_REG_ADDR, "Must use valid alarm address");
+
+		const auto alarmReg = readRegister<Address>();
+
+		DateTime alarmTime = {};
+		alarmReg.getDate(alarmTime.day);
+		alarmTime.hour = alarmReg.getHours();
+		alarmTime.minute = alarmReg.getMinutes();
+		if constexpr (IsAlarm1)
+			alarmTime.second = alarmReg.getSeconds();
+
+		return alarmTime;
+	}
+
+	template <typename AlarmRate>
+	static inline void setAlarmHelper(const DateTime &alarmTime, const AlarmRate &alarmRate)
+	{
+		constexpr auto IsAlarm1 = util::is_same_v<AlarmRate, Alarm1Rate>;
+		static_assert(IsAlarm1 || util::is_same_v<AlarmRate, Alarm2Rate>, "Must use valid alarm rate");
+
+		using alarm_reg_t = util::conditional_t<IsAlarm1, detail::Alarm1Reg, detail::Alarm2Reg>;
+
+		alarm_reg_t alarmReg;
+		alarmReg.setAlarmRate(alarmRate);
+		alarmReg.setDate(alarmTime.day);
+		alarmReg.setHours(alarmTime.hour);
+		alarmReg.setMinutes(alarmTime.minute);
+		if constexpr (IsAlarm1)
+			alarmReg.setSeconds(alarmTime.second);
+		writeRegister(alarmReg);
+	}
+
+	template <detail::ControlRegFlags AlarmFlag>
+	static inline void enableInterruptHelper()
+	{
+		constexpr auto IsAlarm1Flag = AlarmFlag == detail::ControlRegFlags::A1IE;
+		constexpr auto IsAlarm2Flag = AlarmFlag == detail::ControlRegFlags::A2IE;
+		static_assert(IsAlarm1Flag || IsAlarm2Flag, "Must use valid alarm flag");
+
+		auto controlReg = readRegister<CONTROL_REG_ADDR>();
+		using Flags = typename decltype(controlReg)::Flags;
+		controlReg &= ~Flags::BBSQW;
+		controlReg |= Flags::INTCN | AlarmFlag;
+		writeRegister(controlReg);
+	}
+
+	template <detail::ControlStatusRegFlags AlarmFlag>
+	static inline bool checkAlarmHelper()
+	{
+		constexpr auto IsAlarm1Flag = AlarmFlag == detail::ControlStatusRegFlags::A1F;
+		constexpr auto IsAlarm2Flag = AlarmFlag == detail::ControlStatusRegFlags::A2F;
+		static_assert(IsAlarm1Flag || IsAlarm2Flag, "Must use valid alarm flag");
+
+		const auto alarmStatus = readRegister<CONTROL_STATUS_REG_ADDR>();
+		return alarmStatus == AlarmFlag;
+	}
+
+	template <detail::ControlStatusRegFlags AlarmFlag>
+	static inline void clearAlarmHelper()
+	{
+		constexpr auto IsAlarm1Flag = AlarmFlag == detail::ControlStatusRegFlags::A1F;
+		constexpr auto IsAlarm2Flag = AlarmFlag == detail::ControlStatusRegFlags::A2F;
+		static_assert(IsAlarm1Flag || IsAlarm2Flag, "Must use valid alarm flag");
+
+		auto controlStatusReg = readRegister<CONTROL_STATUS_REG_ADDR>();
+		controlStatusReg &= ~AlarmFlag;
+		writeRegister(controlStatusReg);
+	}
+
+	static uint8_t calcDayOfWeek(uint16_t year, uint8_t month, uint16_t day)
+	{
+		day += month < 3 ? year-- : year - 2;
+		const auto dayOfWeek = (23 * month / 9 + day + 4 + year / 4 - year / 100 + year / 400);
+		return dayOfWeek % 7;
+	}
+};
+
+} // namespace rtc

flags.hpp

@@ -0,0 +1,88 @@
+#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 = 0;
+	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 uint8_t &flag)
+	{
+		data |= flag;
+		return *this;
+	}
+
+	FlagsImpl &operator&=(const FlagsT &flag)
+	{
+		data &= static_cast<uint8_t>(flag);
+		return *this;
+	}
+
+	FlagsImpl &operator&=(const uint8_t &flag)
+	{
+		data &= flag;
+		return *this;
+	}
+
+	FlagsImpl &operator~()
+	{
+		data = ~data;
+		return *this;
+	}
+
+	bool operator==(const FlagsT &flag) const
+	{
+		return data & static_cast<uint8_t>(flag);
+	}
+};
+
+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

registers.hpp

@@ -0,0 +1,413 @@
+#pragma once
+
+#include <stdint.h>
+
+#include "alarms.hpp"
+#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 = 0;
+	uint8_t minutes = 0;
+	uint8_t hours = 0;
+	uint8_t day = 1; // Range 1-7 according to datasheet
+	uint8_t date = 0;
+	uint8_t month_century = 0;
+	uint8_t year = 0;
+
+	//////////////////////////////////////////////////////////////////////////
+
+	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 = 0;
+	uint8_t minutes = 0;
+	uint8_t hours = 0;
+	uint8_t day_date = 0;
+
+	//////////////////////////////////////////////////////////////////////////
+
+	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 Alarm1Rate 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<Alarm1Rate>(dayFormat);
+		}
+		return static_cast<Alarm1Rate>(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 Alarm1Rate &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 = 0;
+	uint8_t hours = 0;
+	uint8_t day_date = 0;
+
+	//////////////////////////////////////////////////////////////////////////
+
+	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 Alarm2Rate 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<Alarm2Rate>(dayFormat);
+		}
+		return static_cast<Alarm2Rate>(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 Alarm2Rate &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,
+};
+
+static inline uint8_t operator~(const ControlRegFlags &flag)
+{
+	return ~static_cast<uint8_t>(flag);
+}
+
+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,
+};
+
+static inline uint8_t operator~(const ControlStatusRegFlags &flag)
+{
+	return ~static_cast<uint8_t>(flag);
+}
+
+struct [[gnu::packed]] ControlStatusReg : FlagsImpl<ControlStatusRegFlags>{};
+
+static_assert(sizeof(ControlStatusReg) == 1, "Invalid control/status register size");
+
+//////////////////////////////////////////////////////////////////////////
+
+struct [[gnu::packed]] AgingOffsetReg
+{
+	uint8_t data = 0;
+};
+
+static_assert(sizeof(AgingOffsetReg) == 1, "Invalid aging offset register size");
+
+//////////////////////////////////////////////////////////////////////////
+
+struct [[gnu::packed]] TempReg
+{
+	uint8_t msb_temp = 0;
+	uint8_t lsb_temp = 0;
+};
+
+static_assert(sizeof(TempReg) == 2, "Invalid temperature register size");
+
+//////////////////////////////////////////////////////////////////////////
+
+} // namespace detail
+
+} // namespace rtc

rtc.cpp

@@ -1,617 +0,0 @@
-/*
- * DS RTC Library: DS1307 and DS3231 driver library
- * (C) 2011 Akafugu Corporation
- *
- * This program is free software; you can redistribute it and/or modify it under the
- * terms of the GNU General Public License as published by the Free Software
- * Foundation; either version 2 of the License, or (at your option) any later
- * version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
- * PARTICULAR PURPOSE.  See the GNU General Public License for more details.
- *
- */
-
-/*
- * DS1307 register map
- *
- *  00h-06h: seconds, minutes, hours, day-of-week, date, month, year (all in BCD)
- *     bit 7 of seconds enables/disables clock
- *     bit 6 of hours toggles 12/24h mode (1 for 12h, 0 for 24h)
- *       when 12h mode is selected bit 5 is high for PM, low for AM
- *  07h: control
- *      bit7: OUT
- *      bit6: 0
- *      bit5: 0
- *      bit4: SQWE
- *      bit3: 0
- *      bit2: 0
- *      bit1: RS0
- *      bit0: RS1
- *  08h-3fh: 56 bytes of SRAM
- *
- * DS3231 register map
- *
- *  00h-06h: seconds, minutes, hours, day-of-week, date, month, year (all in BCD)
- *       bit 7 should be set to zero: The DS3231 clock is always running
- *  07h: A1M1  Alarm 1 seconds
- *  08h: A1M2  Alarm 1 minutes
- *  09h: A1M3  Alarm 1 hour (bit6 is am/pm flag in 12h mode)
- *  0ah: A1M4  Alarm 1 day/date (bit6: 1 for day, 0 for date)
- *  0bh: A2M2  Alarm 2 minutes
- *  0ch: A2M3  Alarm 2 hour (bit6 is am/pm flag in 12h mode)
- *  0dh: A2M4  Alarm 2 day/data (bit6: 1 for day, 0 for date)
- *       <see data sheet page12 for Alarm register mask bit tables:
- *        for alarm when hours, minutes and seconds match set 1000 for alarm 1>
- *  0eh: control
- *      bit7: !EOSC
- *      bit6: BBSQW
- *      bit5: CONV
- *      bit4: RS2
- *      bit3: RS1
- *      bit2: INTCN
- *      bit1: A2IE
- *      bit0: A1IE
- *  0fh: control/status
- *      bit7: OSF
- *      bit6: 0
- *      bit5: 0
- *      bit4: 0
- *      bit3: EN32kHz
- *      bit2: BSY
- *      bit1: A2F alarm 2 flag
- *      bit0: A1F alarm 1 flag
- * 10h: aging offset (signed)
- * 11h: MSB of temp (signed)
- * 12h: LSB of temp in bits 7 and 6 (0.25 degrees for each 00, 01, 10, 11)
- *
- */
-
-#include <avr/io.h>
-
-#define TRUE 1
-#define FALSE 0
-
-#include "../clock.hpp"
-
-#include "../i2c/i2c.hpp"
-using i2c_t = i2c::I2c<i2c::Hardware<100'000>>;
-
-#include "rtc.h"
-
-#define RTC_ADDR 0x68 // I2C address
-#define CH_BIT 7 // clock halt bit
-
-// statically allocated structure for time value
-struct rtc_tm _rtc_tm;
-
-uint8_t dec2bcd(uint8_t d)
-{
-  return ((d/10 * 16) + (d % 10));
-}
-
-uint8_t bcd2dec(uint8_t b)
-{
-  return ((b/16 * 10) + (b % 16));
-}
-
-uint8_t rtc_read_byte(uint8_t offset)
-{
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(offset);
-	i2c_t::stop();
-
-	i2c_t::start<RTC_ADDR>(true);
-	const auto received = i2c_t::read<true>();
-	i2c_t::stop();
-
-	return received;
-}
-
-void rtc_write_byte(uint8_t b, uint8_t offset)
-{
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(offset);
-	i2c_t::write(b);
-	i2c_t::stop();
-}
-
-static bool s_is_ds1307 = false;
-static bool s_is_ds3231 = false;
-
-void rtc_init(void)
-{
-	i2c_t::init();
-
-	// Attempt autodetection:
-	// 1) Read and save temperature register
-	// 2) Write a value to temperature register
-	// 3) Read back the value
-	//   equal to the one written: DS1307, write back saved value and return
-	//   different from written:   DS3231
-
-	uint8_t temp1 = rtc_read_byte(0x11);
-	uint8_t temp2 = rtc_read_byte(0x12);
-
-	rtc_write_byte(0xee, 0x11);
-	rtc_write_byte(0xdd, 0x12);
-
-	if (rtc_read_byte(0x11) == 0xee && rtc_read_byte(0x12) == 0xdd) {
-		s_is_ds1307 = true;
-		// restore values
-		rtc_write_byte(temp1, 0x11);
-		rtc_write_byte(temp2, 0x12);
-	}
-	else {
-		s_is_ds3231 = true;
-	}
-}
-
-// Autodetection
-bool rtc_is_ds1307(void) { return s_is_ds1307; }
-bool rtc_is_ds3231(void) { return s_is_ds3231; }
-
-// Autodetection override
-void rtc_set_ds1307(void) { s_is_ds1307 = true;   s_is_ds3231 = false; }
-void rtc_set_ds3231(void) { s_is_ds1307 = false;  s_is_ds3231 = true;  }
-
-struct rtc_tm* rtc_get_time(void)
-{
-	uint8_t rtc[9];
-	uint8_t century = 0;
-
-	// read 7 bytes starting from register 0
-	// sec, min, hour, day-of-week, date, month, year
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(0x0);
-	i2c_t::stop();
-
-	i2c_t::start<RTC_ADDR>(true);
-	i2c_t::readBytes<7>(rtc);
-	i2c_t::stop();
-
-	// Clear clock halt bit from read data
-	// This starts the clock for a DS1307, and has no effect for a DS3231
-	rtc[0] &= ~(_BV(CH_BIT)); // clear bit
-
-	_rtc_tm.sec = bcd2dec(rtc[0]);
-	_rtc_tm.min = bcd2dec(rtc[1]);
-	_rtc_tm.hour = bcd2dec(rtc[2]);
-	_rtc_tm.mday = bcd2dec(rtc[4]);
-	_rtc_tm.mon = bcd2dec(rtc[5] & 0x1F); // returns 1-12
-	century = (rtc[5] & 0x80) >> 7;
-	_rtc_tm.year = century == 1 ? 2000 + bcd2dec(rtc[6]) : 1900 + bcd2dec(rtc[6]); // year 0-99
-	_rtc_tm.wday = bcd2dec(rtc[3]); // returns 1-7
-
-	if (_rtc_tm.hour == 0) {
-		_rtc_tm.twelveHour = 0;
-		_rtc_tm.am = 1;
-	} else if (_rtc_tm.hour < 12) {
-		_rtc_tm.twelveHour = _rtc_tm.hour;
-		_rtc_tm.am = 1;
-	} else {
-		_rtc_tm.twelveHour = _rtc_tm.hour - 12;
-		_rtc_tm.am = 0;
-	}
-
-	return &_rtc_tm;
-}
-
-void rtc_get_time_s(uint8_t* hour, uint8_t* min, uint8_t* sec)
-{
-	uint8_t rtc[9];
-
-	// read 7 bytes starting from register 0
-	// sec, min, hour, day-of-week, date, month, year
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(0x0);
-	i2c_t::stop();
-
-	i2c_t::start<RTC_ADDR>(true);
-	i2c_t::readBytes<7>(rtc);
-	i2c_t::stop();
-
-	if (sec)  *sec =  bcd2dec(rtc[0]);
-	if (min)  *min =  bcd2dec(rtc[1]);
-	if (hour) *hour = bcd2dec(rtc[2]);
-}
-
-// fixme: support 12-hour mode for setting time
-void rtc_set_time(struct rtc_tm* tm_)
-{
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(0x0);
-
-	uint8_t century;
-	if (tm_->year > 2000) {
-		century = 0x80;
-		tm_->year = tm_->year - 2000;
-	} else {
-		century = 0;
-		tm_->year = tm_->year - 1900;
-	}
-
-	// clock halt bit is 7th bit of seconds: this is always cleared to start the clock
-	i2c_t::write(dec2bcd(tm_->sec)); // seconds
-	i2c_t::write(dec2bcd(tm_->min)); // minutes
-	i2c_t::write(dec2bcd(tm_->hour)); // hours
-	i2c_t::write(dec2bcd(tm_->wday)); // day of week
-	i2c_t::write(dec2bcd(tm_->mday)); // day
-	i2c_t::write(dec2bcd(tm_->mon) + century); // month
-	i2c_t::write(dec2bcd(tm_->year)); // year
-
-	i2c_t::stop();
-}
-
-void rtc_set_time_s(uint8_t hour, uint8_t min, uint8_t sec)
-{
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(0x0);
-
-	// clock halt bit is 7th bit of seconds: this is always cleared to start the clock
-	i2c_t::write(dec2bcd(sec)); // seconds
-	i2c_t::write(dec2bcd(min)); // minutes
-	i2c_t::write(dec2bcd(hour)); // hours
-
-	i2c_t::stop();
-}
-
-// DS1307 only (has no effect when run on DS3231)
-// halt/start the clock
-// 7th bit of register 0 (second register)
-// 0 = clock is running
-// 1 = clock is not running
-void rtc_run_clock(bool run)
-{
-  if (s_is_ds3231) return;
-
-  uint8_t b = rtc_read_byte(0x0);
-
-  if (run)
-    b &= ~(_BV(CH_BIT)); // clear bit
-  else
-    b |= _BV(CH_BIT); // set bit
-
-  rtc_write_byte(b, 0x0);
-}
-
-// DS1307 only
-// Returns true if the clock is running, false otherwise
-// For DS3231, it always returns true
-bool rtc_is_clock_running(void)
-{
-  if (s_is_ds3231) return true;
-
-  uint8_t b = rtc_read_byte(0x0);
-
-  if (b & _BV(CH_BIT)) return false;
-  return true;
-}
-
-void ds3231_get_temp_int(int8_t* i, uint8_t* f)
-{
-	uint8_t msb, lsb;
-
-	*i = 0;
-	*f = 0;
-
-	if (s_is_ds1307) return; // only valid on DS3231
-
-	i2c_t::start<RTC_ADDR>(false);
-	// temp registers 0x11 and 0x12
-	i2c_t::write(0x11);
-	i2c_t::stop();
-
-	i2c_t::start<RTC_ADDR>(true);
-	msb = i2c_t::read(); // integer part (in twos complement)
-	lsb = i2c_t::read<true>(); // fraction part
-
-	// integer part in entire byte
-	*i = msb;
-	// fractional part in top two bits (increments of 0.25)
-	*f = (lsb >> 6) * 25;
-
-	// float value can be read like so:
-	// float temp = ((((short)msb << 8) | (short)lsb) >> 6) / 4.0f;
-}
-
-void rtc_force_temp_conversion(uint8_t block)
-{
-	if (s_is_ds1307) return; // only valid on DS3231
-
-	// read control register (0x0E)
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(0x0E);
-	i2c_t::stop();
-
-	i2c_t::start<RTC_ADDR>(true);
-	uint8_t ctrl = i2c_t::read<true>();
-	i2c_t::stop();
-
-	ctrl |= 0b00100000; // Set CONV bit
-
-	// write new control register value
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(0x0E);
-	i2c_t::write(ctrl);
-	i2c_t::stop();
-
-	if (!block) return;
-
-	// Temp conversion is ready when control register becomes 0
-	do {
-		// Block until CONV is 0
-		i2c_t::start<RTC_ADDR>(false);
-		i2c_t::write(0x0E);
-		i2c_t::stop();
-
-		i2c_t::start<RTC_ADDR>(true);
-		// HACK: Missing stop after read, might still work though
-	} while ((i2c_t::read<true>() & 0b00100000) != 0);
-}
-
-
-#define DS1307_SRAM_ADDR 0x08
-
-// SRAM: 56 bytes from address 0x08 to 0x3f (DS1307-only)
-void rtc_get_sram(uint8_t* data)
-{
-	// cannot receive 56 bytes in one go, because of the TWI library buffer limit
-	// so just receive one at a time for simplicity
-  	for(int i=0;i<56;i++)
-		data[i] = rtc_get_sram_byte(i);
-}
-
-void rtc_set_sram(uint8_t *data)
-{
-	// cannot send 56 bytes in one go, because of the TWI library buffer limit
-	// so just send one at a time for simplicity
-  	for(int i=0;i<56;i++)
-		rtc_set_sram_byte(data[i], i);
-}
-
-uint8_t rtc_get_sram_byte(uint8_t offset)
-{
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(DS1307_SRAM_ADDR + offset);
-	i2c_t::stop();
-
-	i2c_t::start<RTC_ADDR>(true);
-	const auto received = i2c_t::read<true>();
-	i2c_t::stop();
-	return received;
-}
-
-void rtc_set_sram_byte(uint8_t b, uint8_t offset)
-{
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(DS1307_SRAM_ADDR + offset);
-	i2c_t::write(b);
-	i2c_t::stop();
-}
-
-void rtc_SQW_enable(bool enable)
-{
-	if (s_is_ds1307) {
-		i2c_t::start<RTC_ADDR>(false);
-		i2c_t::write(0x07);
-		i2c_t::stop();
-
-		// read control
-		i2c_t::start<RTC_ADDR>(true);
-		uint8_t control = i2c_t::read<true>();
-		i2c_t::stop();
-
-		if (enable)
-			control |=  0b00010000; // set SQWE to 1
-		else
-			control &= ~0b00010000; // set SQWE to 0
-
-		// write control back
-		i2c_t::start<RTC_ADDR>(false);
-		i2c_t::write(0x07);
-		i2c_t::write(control);
-		i2c_t::stop();
-
-	}
-	else { // DS3231
-		i2c_t::start<RTC_ADDR>(false);
-		i2c_t::write(0x0E);
-		i2c_t::stop();
-
-		// read control
-		i2c_t::start<RTC_ADDR>(true);
-		uint8_t control = i2c_t::read<true>();
-		i2c_t::stop();
-
-		if (enable) {
-			control |=  0b01000000; // set BBSQW to 1
-			control &= ~0b00000100; // set INTCN to 0
-		}
-		else {
-			control &= ~0b01000000; // set BBSQW to 0
-		}
-
-		// write control back
-		i2c_t::start<RTC_ADDR>(false);
-		i2c_t::write(0x0E);
-		i2c_t::write(control);
-		i2c_t::stop();
-	}
-}
-
-void rtc_SQW_set_freq(enum RTC_SQW_FREQ freq)
-{
-	if (s_is_ds1307) {
-		i2c_t::start<RTC_ADDR>(false);
-		i2c_t::write(0x07);
-		i2c_t::stop();
-
-		// read control (uses bits 0 and 1)
-		i2c_t::start<RTC_ADDR>(true);
-		uint8_t control = i2c_t::read<true>();
-		i2c_t::stop();
-
-		control &= ~0b00000011; // Set to 0
-		control |= freq; // Set freq bitmask
-
-		// write control back
-		i2c_t::start<RTC_ADDR>(false);
-		i2c_t::write(0x07);
-		i2c_t::write(control);
-		i2c_t::stop();
-
-	}
-	else { // DS3231
-		i2c_t::start<RTC_ADDR>(false);
-		i2c_t::write(0x0E);
-		i2c_t::stop();
-
-		// read control (uses bits 3 and 4)
-		i2c_t::start<RTC_ADDR>(true);
-		uint8_t control = i2c_t::read<true>();
-		i2c_t::stop();
-
-		control &= ~0b00011000; // Set to 0
-		control |= (freq << 4); // Set freq bitmask
-
-		// write control back
-		i2c_t::start<RTC_ADDR>(false);
-		i2c_t::write(0x0E);
-		i2c_t::write(control);
-		i2c_t::stop();
-	}
-}
-
-void rtc_osc32kHz_enable(bool enable)
-{
-	if (!s_is_ds3231) return;
-
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(0x0F);
-	i2c_t::stop();
-
-	// read status
-	i2c_t::start<RTC_ADDR>(true);
-	uint8_t status = i2c_t::read<true>();
-	i2c_t::stop();
-
-	if (enable)
-		status |= 0b00001000; // set to 1
-	else
-		status &= ~0b00001000; // Set to 0
-
-	// write status back
-	i2c_t::start<RTC_ADDR>(false);
-	i2c_t::write(0x0F);
-	i2c_t::write(status);
-	i2c_t::stop();
-}
-
-// Alarm functionality
-// fixme: should decide if "alarm disabled" mode should be available, or if alarm should always be enabled
-// at 00:00:00. Currently, "alarm disabled" only works for ds3231
-void rtc_reset_alarm(void)
-{
-	if (s_is_ds1307) {
-		rtc_set_sram_byte(0, 0); // hour
-		rtc_set_sram_byte(0, 1); // minute
-		rtc_set_sram_byte(0, 2); // second
-	}
-	else {
-		// writing 0 to bit 7 of all four alarm 1 registers disables alarm
-		rtc_write_byte(0, 0x07); // second
-		rtc_write_byte(0, 0x08); // minute
-		rtc_write_byte(0, 0x09); // hour
-		rtc_write_byte(0, 0x0a); // day
-	}
-}
-
-// fixme: add an option to set whether or not the INTCN and Interrupt Enable flag is set when setting the alarm
-void rtc_set_alarm_s(uint8_t hour, uint8_t min, uint8_t sec)
-{
-	if (hour > 23) return;
-	if (min > 59) return;
-	if (sec > 59) return;
-
-	if (s_is_ds1307) {
-		rtc_set_sram_byte(hour, 0); // hour
-		rtc_set_sram_byte(min,  1); // minute
-		rtc_set_sram_byte(sec,  2); // second
-	}
-	else {
-		/*
-		 *  07h: A1M1:0  Alarm 1 seconds
-		 *  08h: A1M2:0  Alarm 1 minutes
-		 *  09h: A1M3:0  Alarm 1 hour (bit6 is am/pm flag in 12h mode)
-		 *  0ah: A1M4:1  Alarm 1 day/date (bit6: 1 for day, 0 for date)
-		 *  Sets alarm to fire when hour, minute and second matches
-		 */
-		rtc_write_byte(dec2bcd(sec),  0x07); // second
-		rtc_write_byte(dec2bcd(min),  0x08); // minute
-		rtc_write_byte(dec2bcd(hour), 0x09); // hour
-		rtc_write_byte(0b10000001,         0x0a); // day (upper bit must be set)
-
-		// clear alarm flag
-		uint8_t val = rtc_read_byte(0x0f);
-		rtc_write_byte(val & ~0b00000001, 0x0f);
-	}
-}
-
-void rtc_set_alarm(struct rtc_tm* tm_)
-{
-	if (!tm_) return;
-	rtc_set_alarm_s(tm_->hour, tm_->min, tm_->sec);
-}
-
-void rtc_get_alarm_s(uint8_t* hour, uint8_t* min, uint8_t* sec)
-{
-	if (s_is_ds1307) {
-		if (hour) *hour = rtc_get_sram_byte(0);
-		if (min)  *min  = rtc_get_sram_byte(1);
-		if (sec)  *sec  = rtc_get_sram_byte(2);
-	}
-	else {
-		*sec  = bcd2dec(rtc_read_byte(0x07) & ~0b10000000);
-		*min  = bcd2dec(rtc_read_byte(0x08) & ~0b10000000);
-		*hour = bcd2dec(rtc_read_byte(0x09) & ~0b10000000);
-	}
-}
-
-struct rtc_tm* rtc_get_alarm(void)
-{
-	uint8_t hour, min, sec;
-
-	rtc_get_alarm_s(&hour, &min, &sec);
-	_rtc_tm.hour = hour;
-	_rtc_tm.min = min;
-	_rtc_tm.sec = sec;
-	return &_rtc_tm;
-}
-
-bool rtc_check_alarm(void)
-{
-	if (s_is_ds1307) {
-		uint8_t hour = rtc_get_sram_byte(0);
-		uint8_t min  = rtc_get_sram_byte(1);
-		uint8_t sec  = rtc_get_sram_byte(2);
-
-		uint8_t cur_hour, cur_min, cur_sec;
-		rtc_get_time_s(&cur_hour, &cur_min, &cur_sec);
-
-		if (cur_hour == hour && cur_min == min && cur_sec == sec)
-			return true;
-		return false;
-	}
-	else {
-		// Alarm 1 flag (A1F) in bit 0
-		uint8_t val = rtc_read_byte(0x0f);
-
-		// clear flag when set
-		if (val & 1)
-			rtc_write_byte(val & ~0b00000001, 0x0f);
-
-		return val & 1 ? 1 : 0;
-	}
-}

rtc.h

@@ -1,106 +0,0 @@
-/*
- * DS RTC Library: DS1307 and DS3231 driver library
- * (C) 2011 Akafugu Corporation
- *
- * This program is free software; you can redistribute it and/or modify it under the
- * terms of the GNU General Public License as published by the Free Software
- * Foundation; either version 2 of the License, or (at your option) any later
- * version.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
- * PARTICULAR PURPOSE.  See the GNU General Public License for more details.
- *
- */
-
-#ifndef DS1307_H
-#define DS1307_H
-
-#include <stdbool.h>
-#include <avr/io.h>
-
-#define DS1307_SLAVE_ADDR 0b11010000
-
-/** Time structure
- *
- * Both 24-hour and 12-hour time is stored, and is always updated when rtc_get_time is called.
- *
- * When setting time and alarm, 24-hour mode is always used.
- *
- * If you run your clock in 12-hour mode:
- * - set time hour to store in twelveHour and set am to true or false.
- * - call rtc_12h_translate (this will put the correct value in hour, so you don't have to
- *   calculate it yourself.
- * - call rtc_set_alarm or rtc_set_clock
- *
- * Note that rtc_set_clock_s, rtc_set_alarm_s, rtc_get_time_s, rtc_set_alarm_s always operate in 24-hour mode
- * and translation has to be done manually (you can call rtc_24h_to_12h to perform the calculation)
- *
- */
-struct rtc_tm {
-	int sec;      // 0 to 59
-	int min;      // 0 to 59
-	int hour;     // 0 to 23
-	int mday;     // 1 to 31
-	int mon;      // 1 to 12
-	int year;     // year-99
-	int wday;     // 1-7
-
-    // 12-hour clock data
-    bool am; // true for AM, false for PM
-    int twelveHour; // 12 hour clock time
-};
-
-// statically allocated
-extern struct rtc_tm _rtc_tm;
-
-// Initialize the RTC and autodetect type (DS1307 or DS3231)
-void rtc_init(void);
-
-// Autodetection
-bool rtc_is_ds1307(void);
-bool rtc_is_ds3231(void);
-
-void rtc_set_ds1307(void);
-void rtc_set_ds3231(void);
-
-// Get/set time
-// Gets the time: Supports both 24-hour and 12-hour mode
-struct rtc_tm* rtc_get_time(void);
-// Gets the time: 24-hour mode only
-void rtc_get_time_s(uint8_t* hour, uint8_t* min, uint8_t* sec);
-// Sets the time: Supports both 24-hour and 12-hour mode
-void rtc_set_time(struct rtc_tm* tm_);
-// Sets the time: Supports 12-hour mode only
-void rtc_set_time_s(uint8_t hour, uint8_t min, uint8_t sec);
-
-// start/stop clock running (DS1307 only)
-void rtc_run_clock(bool run);
-bool rtc_is_clock_running(void);
-
-// Read Temperature (DS3231 only)
-void  ds3231_get_temp_int(int8_t* i, uint8_t* f);
-void rtc_force_temp_conversion(uint8_t block);
-
-// SRAM read/write DS1307 only
-void rtc_get_sram(uint8_t* data);
-void rtc_set_sram(uint8_t *data);
-uint8_t rtc_get_sram_byte(uint8_t offset);
-void rtc_set_sram_byte(uint8_t b, uint8_t offset);
-
-  // Auxillary functions
-enum RTC_SQW_FREQ { FREQ_1 = 0, FREQ_1024, FREQ_4096, FREQ_8192 };
-
-void rtc_SQW_enable(bool enable);
-void rtc_SQW_set_freq(enum RTC_SQW_FREQ freq);
-void rtc_osc32kHz_enable(bool enable);
-
-// Alarm functionality
-void rtc_reset_alarm(void);
-void rtc_set_alarm(struct rtc_tm* tm_);
-void rtc_set_alarm_s(uint8_t hour, uint8_t min, uint8_t sec);
-struct rtc_tm* rtc_get_alarm(void);
-void rtc_get_alarm_s(uint8_t* hour, uint8_t* min, uint8_t* sec);
-bool rtc_check_alarm(void);
-
-#endif