If there is space in the pic driving the display

this may be useful for 10 steps of intencity 10% to 100%

the routine needs to be called about 4000/second for upto 8
digits

wrap the display routine in a counter
        1) Decriment the counter every time the code is called.
        2) When the counter reaches 'n' the dimming level (9
low - 0 high)
                switch of the display driver (blank the displayed
segment)
        3) When the count reaches zero
                reset the counter to 10
                call the display routine
        4) Return to other functions

the number of dimming levels can be increased or decreased
depending upon the display requirements and the number of
free instructions per second of the processor.

for more steps call the routine more often and increase the
count range
ie      call the display routine 8000/second and use a counter
range of 20 for 20 steps (5%/step).

hope this is usefull