Frequency measurement method and device based on single-chip microcomputer

Abstract

The invention provides a frequency measurement method and device based on a single-chip microcomputer. The method comprises the following steps: receiving a measured frequency signal; starting counting according to a first trigger signal of the tested frequency signal to obtain a count value, recording the number of times of triggering according to the trigger signal of the tested frequency signal, and storing the count value and the number of times of triggering in a direct memory access mode; if it is judged that the triggering times are larger than or equal to a triggering threshold value, stopping frequency measurement on the measured frequency signal; and according to the triggering times, the count value and the reference signal frequency, calculating to obtain the frequency of the measured frequency signal, wherein the reference signal frequency is the counting frequency. The device is used for executing the method. According to the frequency measurement method and device based on the single-chip microcomputer provided by the embodiment of the invention, the working efficiency of the single-chip microcomputer is improved.

Description

technical field [0001] The invention relates to the technical field of data processing, in particular to a single-chip microcomputer-based frequency measurement method and device. Background technique [0002] In the field of electronic testing, frequency is one of the basic parameters. The frequency signal has strong anti-interference, is easy to transmit, and can obtain high measurement accuracy. The measurement of frequency is also one of the most basic measurements. [0003] At present, there are two commonly used methods for frequency measurement: frequency measurement method and period measurement method, both of which will generate an error of ±1 period of the signal to be measured. The frequency measurement method is suitable for measuring high-frequency signals, and the period measurement method is suitable for measuring low-frequency signals. In a small industrial control circuit system, a single-chip microcomputer is generally used as the main control unit, and t...

AI Technical Summary

Problems solved by technology

There are two conventional methods. The first one is to use a built-in timer of a single-chip microcomputer to complete the frequency measurement by using the frequency measurement method or the period measurement method. The advantage is that the method is simple, and the disadvantage is that the accuracy is not high, and the frequency range needs to be limited.

The second method uses two single-chip built-in timers to complete the equal-precision frequency measurement method. The advantage is that the precision is high, and the disadvantage is that the frequency measurement process is complicated.

The above-mentioned frequency measurement method has the following problems: (1) the accuracy of frequency measurement is generally related to the measurement duration, and the single-chip microcomputer is a single-threaded work, and long-term frequency measurement will affect the execution of other tasks of the single-chip microcomputer; (2) the single-chip microcomputer receives the measured frequency signal Using the interrupt method, the higher frequency signal will frequently trigger the interrupt of the single-chip microcomputer, which will affect the work of the single-chip microcomputer, which may seriously cause program abnormality; (3) The measured frequency signal may appear intermittent, that is, within one measurement time, two segments are interrupted. A section of the signal is lost in the middle of the test signal, resulting in an error in frequency calculation; (4) Due to circuit and other environmental reasons, within a measurement time, there are jitters and abnormal noises in some cycles of the measured signal, and the single-chip microcomputer generates multiple times in one cycle. interrupt, which will cause errors in the frequency calculation

Images