need a suggestion...?

[dani]

Hi all,
I am working on a task in which I have to maintain temperature of a device at a specified level for a given period of time. And may repeat 1 to 25 times in the form of cycles. Also I need to track out total elapsed time of each cycle. Temperature will be controlled by controlling different relays. Temperature readings and cycle status along with elapsed time will be displayed on LCD. Now I have a doubt in my mind, that...
SHOULD I use externall RTC chip to track the timing or Intreuppet driven machanisim will be sufficient for this task.
So please give me suggesions on the basis of your experiences.
Also Note.. timing is criticle in the whole task.
:sho

[Neutone]

I posted some time keeping routines in the code libary. PWM a heater coil is an easy task if you use counters for the on and off cycle. If you use a system tick you get results that are consistant and have plenty of time for the LCD.