sparkfun RV-8803 Hook-Up Manual page 19

rtc.disableAllInterrupts();
rtc.setCountdownTimerFrequency(COUNTDOWN_TIMER_FREQUENCY_64_HZ);
rtc.setCountdownTimerClockTicks(224);
rtc.enableHardwareInterrupt(TIMER_INTERRUPT);
rtc.setCountdownTimerEnable(ENABLE);
lastInterruptTime = millis(); //Change millis() to micros() if you end up using the 4096 Hz counter
The loop checks if the countdown interrupt flag (FLAG_TIMER) has been updated using the
prints the time between interrupts (in milliseconds) over serial.
Note: If you select the 4096 Hz counter, make sure to switch all calls to the millis function to call the micros function instead.
Example 4C - Periodic Interrupt
The last interrupt example demonstrates how to generate a periodic pulse from the RV-8803. This is very similar to the previous example but instead of
setting a custom time between interrupts, we configure the RV-8803 to pulse the interrupt pin every second or every minute using the
setPeriodicTimeUpdateFrequency();
rtc.setPeriodicTimeUpdateFrequency(TIME_UPDATE_1_SECOND); //Can also use TIME_UPDATE_1_MINUTE
The loop checks if the periodic interrupt flag (FLAG_UPDATE) has been updated using the
prints the time between interrupts (in milliseconds) over serial.
Example 5 - Timestamp
This example demonstrates how to get a timestamp of an event generated on the EVI pin either by pressing the button on the RTC or toggling the EVI pin
from a microcontroller-generated event. First, just like the other examples, we need to initialize the RV-8803 on the I C bus. Next, we enable and
configure the timestamp function:
rtc.setEVIEventCapture(ENABLE); /
rtc.setEVIDebounceTime(EVI_DEBOUNCE_256HZ);
//rtc.setEVIEdgeDetection(RISING_EDGE); // Uncomment to set event detection to button release instead of press
The main loop waits for the FLAG_EVI register to update from an external event on the EVI pin using the
interrupt examples. If that flag is updated and cleared, we capture the date and time stamp of the interrupt and print that data over serial.
function. The code defaults to a 1 second period but you can change to 1 minute by editing this line:
function. If it has, it clears that flag and
getInterruptFlag
function. If it has, it clears that flag and
getInterruptFlag
2
getInterruptFlag();
function like the other