Lpc2000

--- In lpc2000@yahoogroups.com, Mukund Deshmukh <betacomp_ngp@...> 
wrote:
> Well, my plan was to use the timer at 0.9 mil sec (max freq being 
1Khz), and
> average out the reading at 100 mil sec, so that I don't over flow 
the 8 bit
> counter.

Why not use 32-bit counters? 

If you use a 5 kHz timer, you can easily count both phase changes, 
with plenty of safety margin for a maximum 1 kHz signal.

Every 500 interrupts (i.e. 100 ms) the frequency of each channel is 
then:

F = (c / 2 * 10) or F = c * 5

where F is frequency in Hz, c is count of phase changes in the last 
100 ms period.

Brendan