[Solved] using a mask bit dallas rtc

Using Arduino Programming Questions
4

Grumpy_Mike:

but bit 6 is a mask bit so if i set bit6 high i get B01010001(dec83), which totally changes my original 17.

Yes it will. The number 17 is only one way of interpreting what is after all only a pattern of bits. But if you set bit 6 then all the other bits remain the same and that is what matters if I understand your context correctly.

ya but the clock then runs with "83" (or whatever 83 converts to from bcd).

lloyddean:
Untested but something along the line of -

#define setBit(VALUE, BIT)       ((VALUE) |=  (1 << BIT))

#define clearBit(VALUE, BIT)    ((VALUE) &= ~(1 << BIT))

im gonna give this a shot. thank you.