ooh, It's along time since I used Cron jobs.. prob 1998 at lucent tech..
Yes I suppose i am trying to do that, but you have given me an idea, If I had two schedules using the timealarm library
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1263305457/30
one for the current alarm and one for the next alarm, each time an alarm is run, it also reads the SD card to find the next alarm time and command and puts it into the schedule.
(apologies if I am not explaining the very well)
something like this:
on boot:
Read first alarm from schedule on SD card that is due to happen in the future, add this alarm and it's actions to ALARM 1
on ALARM 1 (based on time and Day of week)
Do action, Read next alarm from SD card that is due to happen in the future, Change ALARM 2 to reflect the records time, DOW and actions.
on ALARM 2 (based on time and Day of week)
Do action, Read next alarm from SD card that is due to happen in the future, Change ALARM 1 to reflect the records time, DOW and actions.
(This is all based on the idea that you can't change an alarm that's currently ringing, which may be incorrect, in which case only 1 ALARM is required)
Does that help?
TIA, Stuart.