Dallas Real Time Clock interrupt question

[Nick]

I believe I turned on the SQW with the binary 10010011 / 0x93. Someone in a previous post said I could wake up every second using this OUT/SQW, but it seems it is will waking up many times a second since its a SQW at 32hz.

Wonder if I should do something like an pic internal timer and just sleep and just wake up once a minute.


Here is the datasheet page 9 http://pdfserv.maxim-ic.com/en/ds/DS1307.pdf

Nick

[ckielstra]

For a 1 Hz signal you must set bit0 and bit1 both to zero, with both bits set to 1 you will get a 32kHz signal. Change to binary 10010000 / 0x90.

[Nick]

Yep

Here is a link that also helps

http://www.ccsinfo.com/forum/viewtopic.php?t=1700&highlight=1307+interrupt



I as you can tell I'm new to pics. Here is a dumb question. Can I tell the pic to sleep for 50 seconds then wake up? I see that I can get it to sleep and wake up on an interupt RB0 attached to the RTC, but that is still way more awake time than I need.

Nick

[Mark]

Drive timer0 and wake up on overflow. You can preload the timer value to set the number of seconds.