基于单片机晶振的守时研究

为了简化天文观测守时设备,利用普通晶振和51单片机计数器实现了1个守时时钟,通过单片机串口向外输出秒脉冲和时间.以高精度的计算机64位计数器时间作为准确时间,对该时钟的稳定性进行分析.通过对近25个h时间比对数据的分析,得出以下结论:该时钟秒钟速非常稳定,变化不超过0.5 μs;24个h的小时钟速互差不超过1 ms；经...

Research on the timer based on the common crystal oscillator

To simplify the timing facility of astro-geodetic surveying,a timer based on a common crystal oscillator and a 51 SCM is designed and realized.This timer exports the second pulse and time data using the serial port of the SCM.The precision of the timer is analyzed according to the time data of the high-resolution performance counter of PC.Analyzing the time comparison data which is more than 24 hours,we arrive at some conclusions：the second clock rate is very steady,the error is no more than 0.5 microsecond;the error between the maximal hour clock rate and the minimal hour clock rate in 24 hours is no more than 1 millisecond;the necessary time for time comparison to compute the clock offset and the clock rate is 2 minutes.So the timer could be used in the first-order astronomic surveying.This conclusion is very useful for the micromation of the timer in field astronomic surveying.