how can we measure pulse width using pic12f683

[padma]

I am developing my code in ccs compiler,and i used capture function for measuring pulse width but when ccp1 value is checked,it shows larger deviation for a fixed pulse width and it was spontaneously changing.why it is so?here 4MHZ internal clock source is used and ccp1 is also placed in ISR.

Can anyone help me in this problem?

 

[emailkprajesh]

do not use internal RC clocks. use external crystal.

Rc clocks are not accurate.

 

[Tahmid]

Hi,
The internal clock is not absolutely accurate, so for precision jobs, use external crystal. The value of the internal clock may stray with different factors, like temperature,etc.

Hope this helps.
Tahmid.

 

[padma]

Thank you ..