Arduino library that supports the SEIKO EPSON RX8900 Real-Time Clocks

citriena

I'm not good at English so correcting my English is welcome when it is wrong.

RX8900RTC is an Arduino library that supports the SEIKO EPSON RX8900 Real-Time Clocks.

RX8900 has features of high stability (±5 seconds of month deviation with UA class) and low current consumption (typically 0.7uA when Vdd=3V, Fout=OFF).

This library is baed on the sample sketch by AKIZUKI DENSHI TSUSHO CO.,LTD. for AE-RX8900 module.

The alarm interrupt generation function generates interrupt events for alarm settings such as date, day, hour, and minute settings.

The fixed-cycle timer interrupt function generates interrupt events periodically at any fixed cycle set between 244.14us and 4095 minutes.

The time update interrupt function generates interrupt events at one-second or one-minute intervals.

RX8900RTC myRTC;

void init(void);
void begin(void);

Initialize RX8900. Eatehr of the functions above is available.

uint8_t set(time_t t);
uint8_t write(tmElements_t tm);

static time_t get(void);
static tmElements_t read(void);

void setAlarm(uint8_t minute);
void setAlarm(uint8_t minute, uint8_t hour);

• minute: The minute value to set the alarm to.
• hour: The hour value to set the alarm to.

void setDayAlarm(uint8_t minute, uint8_t hour, uint8_t daydate);

• daydate: The date of the month to set the alarm to.

void setWeekAlarm(uint8_t minute, uint8_t hour, uint8_t daydate);

• daydate: The day(s) of the week to set the alarm to. The days are SUN, MON, TUE, WED, THU, FRI,and SAT.

Multiple days of the week can be set as SUN | SAT

void alarmInterrupt(INTERRUPT_CONTROL_t interrupt);

Specifies /INT status of RX8900 when an alarm interrupt event occurs.

interrupt:

• ENABLE：/INT status changes from HIGH to LOW
• DISABLE：/INT status do not change (remains HIGH).

bool alarm(void)

• Returns true when AF (Alarm Flag) is "1". Otherwise (AF is "0") returns false.
• When AF is "1", writes "0" to clear AF. /INT will changes to HIGH if LOW.

void disableAlarm(void);

Stops alarm function.

• AF (Alarm Flag) value changes from "0" to 1". AF value is retaind until cleared manually.

You can check the AF and clear it with "alarm(void)".

• /INT status changes to LOW if "alarmInterrupt(ENABLE)" is used. /INT status is retained until AF is cleared manually.

The fixed-cycle timer generates interrupt events periodically at a fixed cycle between 244.14us and 4095 minutes.

void setFixedCycleTimer(uint16_t timerCounter, SOURCE_CLOCK_TYPES_t sourceClock);

Set the fixed-cycle timer interval.

• timerCounter：0~4095
• sourceClock:
  • CLOCK_4096HZ：4096Hz
  • CLOCK_64HZ：64Hz
  • SECOND_UPDATE：1Hz (Once per second)
  • MINUTE_UPDATE：1/60Hz (Once per minute)

The fixed-cycle timer interval is [sourceClock] x [timerCounter].

void fixedCycleTimerInterrupt(INTERRUPT_CONTROL_t interrupt);

Specifies /INT status of RX8900 when a fixed-cycle timer interrupt event occurs.

interrupt:

• ENABLE：/INT status changes from HIGH to LOW
• DISABLE：/INT status do not change (remains HIGH).

bool fixedCycleTimer(void);

• Returns true when TF(Timer Flag) is "1". Otherwise (TF is "0") returns false.
• When TF is "1" write "0" to clear TF.

void disableFixedCycleTimer(void);

Stops fixed-cycle timer function.

• TF(Timer Flag) value changes from "0" to 1". TF value is retaind until cleared manually.

You can check the TF and clear it with "fixedCycleTimer(void)".

• /INT status changes LOW if "fixedCycleTimerInterrupt(ENABLE)" is used. /INT status is automatically cleared 7.813ms or 722us (sourceClock is CLOCK_4096HZ) after the event occured.

• When the source clock has been set to "SECOND_UPDATE" or "MINUTE_UPDATE", the timing of both countdown and interrupts is coordinated with the internal clock update timing.
• The first countdown timing is therefore not exact one sourceClock cycle from the start. The first fixedCycleTimer interrupt event will occure ealier than fixed-cycle.

The time update interrupt function generates interrupt events at one-second or one-minute intervals.

The events will occure according to the timing of the internal clock update.

The time update interrupt function can not be fully stopped.

void setTimeUpdateTimer(USEL_t usel);

Set time update timer interval.

usel:

• UPDATE_SECOND_INT: interrupt event will occure once per second.
• UPDATE_MINUTE_INT: interrupt event will occure once per minute.

void timeUpdateTimerInterrupt(INTERRUPT_CONTROL_t interrupt);

Specifies /INT status of RX8900 when a time update interrupt event occurs.

interrupt:

• ENABLE：/INT status changes from HIGH to LOW
• DISABLE：/INT status do not change (remains HIGH).

bool timeUpdateTimer(void);

• Returns true when UF (Update Flag) is "1". Otherwise (UF is "0") returns false.
• When UF is "1" write "0" to cleart UF.

• UF(Updater Flag) value changes from "0" to 1". UF value is retaind until cleared manually.

You can check the UF and clear it with "timeUpdateTimer(void)".

• /INT status changes LOW if "timeUpdateTimerInterrupt(ENABLE)" is used. /INT status is automatically cleared 15.63ms (usel is UPDATE_MINUTE_INT) or 500ms (usel is UPDATE_SECOND_INT) after the event occured.

float temperature(void);

Returns internal temperature sensor value in Celcius.

See sample skeches for basic usage.

See Application Manual for details of each function. https://www5.epsondevice.com/en/products/rtc/rx8900ce.html

• rename some functions constants and variables

• bug fix: modify WEEK_TYPES_t definition