Intelligent digital frequency meter is widely applied in the modern industrial technology, whose role is to realize the signal measurement of the cycle frequency. Based on the single-chip microcomputer, and introduced by relative the periphery circuits, a digital frequency meter system was designed and established. The hardware circuit consisted of the single-chip microprocessors, signal shaping and amplification circuits, DC circuits, trigger circuit, display circuit, and other components. System design through the basic idea is to clamp voltage circuit of the input signal shaping，op amp circuit from the input signal amplification, by the trigger circuit latches the input signal to achieve, complete single-chip microprocessor signal processing and computing, the use of decoder decoding, in the LED display on the frequency of significant parameters, as measured.Show that the actual operation, system designed to run normal, andthe results of the correct. At the same time, by shaping the waveform of the input signal can be achieved on a variety of cyclical changes in the frequency and signal parameter measurement cycle, the sensor with the appropriate, the system also enables a variety of non-periodic signal power measurement parameters, such as the frequency of mechanical vibration, speed, the frequency of sound.
Key words：Digital frequency meter，single-chip microcomputer system,，hardware design
