RC Oscillator

Hi,
Has anyone tried to see how accurate and stable a simple resistor capacitor oscillator would be on a PIC chip ?
I am aware that temp/tolarance etc has a part to play, but if I wanted to have something "cheap" what would be my tradeoffs ?
I only have a short timing period < 20 minutes.
thanks
kind regards
Peter

If accurate timing or a particularly fast clock aren't required then an RC oscillator works fine.

If you want to give it a try, this is basically all you need to know:

- R between Vdd and OSC1
- C between OSC1 and Vss
- R should be between 3k and 100k
- C should be at least 20pF
- Frequency=1/(Pi*R*C)