RTC Module (Part 3)
Now that we have the hardware and the routines and functions ready, let’s apply them to a simple application. This one will print “tic”, wait half a second, print “tac” followed by the second index. (Real nutty stuff :-[)
void loop() {
int pinState = ((PINB >> oneHertzPin) & 0x01);
if (lastPinState != pinState) {
if (pinState) {
Serial.print("tic ");
}
else {
Serial.print ("tac ");
byte result = bcdTobin(rtc_readRegister(0x00));
Serial.println(result, DEC);
}
}
lastPinState = pinState;
delay(10);
}
Note: As the data is stored in BCD, I am using simple converters, namely bcdTobin and bcdTobcd
byte binTobcd (byte binValue) {
return (((binValue / 10) << 4) | (binValue % 10));
}
byte bcdTobin (byte bcdValue) {
return ((((bcdValue >> 4) & 0x0F) * 10) + (bcdValue & 0x0F));
}
The loop routine contains a level sensor attached to the 1 hertz signal input. Every change triggers a specific action which “tics” and “tacs” time. Second index is read on “tacs”. Just like this:
Coming next: time setting, stand alone clock application