51单片机

AD7705如何校正？

2020-01-23 14:44发布

站内问答 / 51单片机
2341 14 14
线性测量参考方程Y=aX+b 通过两个点(X1,Y1),(X2,Y2)求解实际电路的a和b
可以通过两者计算增益误差和偏移误差

但实际中电流未必呈线性,可以多采集几个点进行校准
友情提示: 此问题已得到解决，问题已经关闭,关闭后问题禁止继续编辑，回答。
14条回答
imfv
2020-01-24 08:53
there are two issues:

1) unknown resistor value: you can easily work that into the program, assuming that the resistor value is stable.

let's say that you apply Vs to the divider network / adc and the adc reading is ADCs.
  1. #define Vs   10000ul //Vs is 10000mv
  2. #define ADCs 456 //associated adc reading is 456

  4. #define ADC2V(adc)  ((adc)*Vs / ADCs) //convert adc reading to voltage reading, in mv
复制代码this macro assumes 1) linearity and 2) no zero offset

2) to correct for non-linearity (and offset), you need a lot more work and the likely solution is a table.

一周热门 更多>