【abstract】Digital, intellective, automatic and minitype are the developing trends of modern measure equipment . As a commonly used equipment in the lab, and with its 50 years developing history, frequency meter has become a very typical digital and intellective device and are going to be minitype. When designing an electrical circuit, people always intend to use as little hardware as possible and try to use software to be the substitute of the hardware, for it’s much easier to modify software than hardware. For example, modifying a few rows of program is much easier than changing several lines on the PCB board. So circuit based on MPU is more flexible than traditional circuit.
This text introduced a design scheme of the high-precision frequency meter based on AT89S52, including its system organization , working elements and software design. Besides described the frequency measurement using multi-cycle synchronous, including the circuit design of synchronous port and the measuring element. This frequency measure meter combines MPU with frequency measuring technology, can facilitate the realization of multi-cycle synchronous measuring and the flexible automatically control. At the mean time increased the precision of measurement.
【key words】 frequency meter SCM digital interrupt LCD1602
