DS3234; Deactivating an alarm

Other Hardware General Electronics
1

I'm using the library for the DS3234 found here:GitHub - rodan/ds3234: arduino library for DS3234 RTC

I've got alarms to work, but now I need to deactivate one. This line is what activates, but I don't understand bits and stuff enough to figure out how to turn off Alarm 1.

 // activate Alarm1
    DS3234_set_creg(cs, DS3234_INTCN | DS3234_A1IE);

Bit 1: Alarm 2 Interrupt Enable (A2IE). When set to logic 1, this bit permits the alarm 2 flag (A2F) bit in the status register to assert INT/SQW (when INTCN = 1). When the A2IE bit is set to logic 0 or INTCN is set to logic 0, the A2F bit does not initiate an interrupt signal. The A2IE bit is disabled (logic 0) when power is first applied.
Bit 0: Alarm 1 Interrupt Enable (A1IE). When set to logic 1, this bit permits the alarm 1 flag (A1F) bit in the status register to assert INT/SQW (when INTCN = 1). When the A1IE bit is set to logic 0 or INTCN is set to logic 0, the A1F bit does not initiate the INT/SQW sig- nal. The A1IE bit is disabled (logic 0) when power is first applied.

taken from the data sheet:

When I activate alarm 1, I need to deactivate alarm 2, because it could fire off prematurely. And vise versa--when I activate alarm 2, I need to deactivate alarm 1. I know it must be simple…
thanks

2

It looks like its just a bit for each alarm:

 // activate only Alarm1
    DS3234_set_creg(cs, DS3234_INTCN | DS3234_A1IE);

 // activate only Alarm2
    DS3234_set_creg(cs, DS3234_INTCN | DS3234_A2IE);

 // activate Alarm1 and Alarm2
    DS3234_set_creg(cs, DS3234_INTCN | DS3234_A1IE | DS3234_A2IE) ;

 // deactivate alarms
    DS3234_set_creg(cs, DS3234_INTCN);
3

Thanks! I see how that works again. I've tried wrapping my brain around it but it doesn't stick. After rereading the arduino reference page on bitwise, I see that you are just adding the binary digits together. I couldn't figure out how it knew what those things were, like DS3234_INTCN, and DS3234_A2IE , but I found in the library's .h file that their defined, as 1, 2 4, etc, representing binary numbers. So just putting in the INTCN will 'take out' the alarm values. Kinda neat when you understand it! Thanks again.