Capture Custom Interrupt Code

[Dave Squibb]

Hello all,
I am trying to use the two Capture modules CCP1 and CCP2 on a PIC18F2550 to measure the time difference between two pulses. The rising edge of the first on CCP1 clears Timer 1 and the rising edge
on CCP2 saves Timer 1 value to variables HIGH and LOW. This value is sent out over UART1.

In practice 0x00 is sent out on UART1 at 1mS intervals until the first pulse is received. UART1 output then ceases. The interrupt looks like it is being called but not cleared. This should be done in the Interrupt Handler code.

Could someone have a look please?

CCP.fcfx

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[Benj]

Hello,

The Timer component under Data might be an option for you to avoid CCP complications.

I'll have a look at your program for you.

[Dave Squibb]

Thanks Benj, that would be good.
Dave.

[Dave Squibb]

Have you had a chance to look at this yet Benj?
Thanks,
Dave.

[Benj]

Hi Dave,

I had a look and didn't spot anything obvious. Have you tried the timer component to see if that will do what you need?

[Dave Squibb]

Hi Benj,
The Timer component works well in this instance because the code is doing nothing else at this point so I can poll the 2 inputs for a change of state. The CCP code has the advantage of edge triggered interrupts. (INT pins are tied up with other things)
Dave.