基于AD7799的数据校正与滤波方法

Correction and Filtering Method Based on AD7799

为了解决A/D转换系统中因为误差与滤波算法导致的采集数据失真问题,提出了一种通过计算增益误差与偏移误差进行数据校正并且使用改进的移动平均滤波器进行滤波的方法。该滤波器能够减轻传统移动平均滤波器抗大脉冲干扰能力差的问题。系统使用STM32作为主控芯片获取AD7799芯片的原始数据。使用两个基准电压源计算出系统的增益误差与偏移误差进行数据的校正,之后将校正后的数据进行滤波处理并且通过串口协议完成最终数据的输出。实验表明,该方法处理后的采样值能够更准确地反应真实数据,在自动化控制领域有良好的应用前景。

In order to solve the problem of data distortion caused by error and filtering algorithm in A/D converter,a method of data correction by calculating gain error and offset error then filtering by using improved moving average filter is proposed.The filter can enhance the ability to suppress peak pulse interference.The system uses STM32 as the master chip to obtain the original data of AD7799 chip.The gain error and offset error of the system are calculated by using two reference voltage for data correction,and then the corrected data are filtered and the final data output is completed through serial port.Experiments show that the values obtained by this method can reflect the data collected more accurately,and it has a good application in the field of automatic control.