Application of first-order complementary filtering to STM32 ADC acquisition

Everybody knows ,adc collection , Regardless of the resolution , In particular, the values of collected voltage and current have a certain drift , For example, drift 100mv Left and right is a very normal phenomenon .

Many people use average filtering , What I want to say here is that it's actually useless , I've been using this before , The effect of sincerity is very poor .

In fact, this question can be used   Average filtering   Add    First order complementary filtering   Relatively perfect filtering of fluctuations .

I only use average filter to drift in 100mv, With complementary filtering, the drift is basically only 10mv. It's already quite perfect .

Let go 10 Times of words , Yours ad The values are basically completely constant .

Here is the code , I won't introduce the idea of first-order complementary filtering , In fact, it is a matter of weight , Which moment do you believe more ？ Do not understand their own Baidu .

1. void DEVICE_INFO::TX_updata()

2. {

3.  

4. // Use a first-order complementary filtering algorithm

5. static u16 bre_i=0;

6. static u16 bre_ii=0;

7. static u16 bre_v=0;

8. static u16 bre_vv=0;

9.  

10. u16 adci,adcv;

11. unsigned char r_buff[33];

12. //TX electric current

13. adci=Get_Adc_Average(ADC_CH11,10); // Here are 10 Sub average filtering

14. adci=(adci*3300)/4096;

15.  

16. //TX_electricity=adci;

17. // voltage

18. adcv=Get_Adc_Average(ADC_CH10,10);

19. adcv=(adcv*3300)/4096;

20.  

21. //TX_voltage=adcv;

22.  

23. // Explain 0.92 and 0.08 Is the weight ,0.000001 Is the processing cycle , I handle it faster here , The unit is s

24.  

25. TX_electricity=0.92*(TX_electricity-bre_i*0.000001)+0.08*bre_ii;

26. TX_voltage=0.92*(TX_voltage-bre_v*0.000001)+0.08*bre_vv;

27.  

28. bre_ii=bre_i; // Save last value

29. bre_i=adci; // Save this value

30.  

31. bre_vv=bre_v;

32. bre_v=adcv; // Save this value

33.  

34. }

I believe that many algorithms are one idea , What will it be like in your own system , Still have to figure it out for yourself .