AbstractThe digital cymometer is a kind of basic measuring instrument. It is widely used in such fields as the spaceflight , electron , observing and controlling ,etc. Basic measurement of it principle, is it examine signal adopt the gate together with standard signal to let at first, the number of the signal pulse that then count through the counter , latch with the latch the result of counting within standard time, use decipher display finally, number show is it is it come out to show to in charge of with LED result that latch. This article mainly narrated the digital frequency meter principle of work by and its each constituent. In this method , the Single - Chip Micro - computer AT89C52 is taken as a core part and it s three programmable timer/ counters are well used and the algorithm for measuring the waveshape period of N signals is also employed.
Key Words : Frequency - counter ; Single - Chip Micro - computer