Examples of 10 software filtering methods)

Craftsman Note: <10 software filtering methods> the article was originally published by the craftsman and published in the [Kan SCM] column of 21ICBSS, which was subsequently reproduced by multiple parties, but most of them did not indicate the original author, depressed ~~~~~~~~, The following is an example of a program implemented by others in C language based on the methods summarized in the craftsman's article:

 

Sample programs for 10 software filtering methods
OurWay was published at 22:24:00

Sample program for 10 software filtering methods (JKRL)
Assume that the data is read from the 8-bit AD (if it is a higher AD, the data type can be defined as int), and the subroutine is get_ad ();

1. subfilter
/* The A value can be adjusted according to the actual situation.
Value is a valid value, and new_value is the current sample value.
The filter returns valid actual values */
# Define A 10

Char value;

Char filter ()
{
Char new_value;
New_value = get_ad ();
If (new_value-value> A) | (value-new_value>)
Return value;
Return new_value;

}

2. Central value filtering method
/* The N value can be adjusted according to the actual situation.
Sort by Bubble Method */
# Define N 11

Char filter ()
{
Char value_buf [N];
Char count, I, j, temp;
For (count = 0; count <N; count ++)
{
Value_buf [count] = get_ad ();
Delay ();
}
For (j = 0; j <N-1; j ++)
{
For (I = 0; I <N-j; I ++)
{
If (value_buf [I]> value_buf [I + 1])
{
Temp = value_buf [I];
Value_buf [I] = value_buf [I + 1];
Value_buf [I + 1] = temp;
}
}
}
Return value_buf [(N-1)/2];
}

3. arithmetic mean Filtering

# Define N 12

Char filter ()
{
Int sum = 0;
For (count = 0; count <N; count ++)
{
Sum + = get_ad ();
Delay ();
}
Return (char) (sum/N );
}

4. Recursive mean filtering (also known as moving average filtering)
# Define N 12

Char value_buf [N];
Char I = 0;

Char filter ()
{
Char count;
Int sum = 0;
Value_buf [I ++] = get_ad ();
If (I = N) I = 0;
For (count = 0; count <N, count ++)
Sum = value_buf [count];
Return (char) (sum/N );
}

5. Median average filtering method (also known as the average filtering method for anti-pulse interference)
# Define N 12

Char filter ()
{
Char count, I, j;
Char value_buf [N];
Int sum = 0;
For (count = 0; count <N; count ++)
{
Value_buf [count] = get_ad ();
Delay ();
}
For (j = 0; j <N-1; j ++)
{
For (I = 0; I <N-j; I ++)
{
If (value_buf [I]> value_buf [I + 1])
{
Temp = value_buf [I];
Value_buf [I] = value_buf [I + 1];
Value_buf [I + 1] = temp;
}
}
}
For (count = 1; count <N-1; count ++)
Sum + = value [count];
Return (char) (sum/(N-2 ));
}

6. amplitude limiting average filtering method
/*
*/
For details, refer to subprograms 1 and 3.

7. First-order lagging Filtering Method
/* To accelerate the processing speed of the program, assume that the base number is 100, a = 0 ~ 100 */

# Define a 50

Char value;

Char filter ()
{
Char new_value;
New_value = get_ad ();
Return (100-a) * value + a * new_value;
}

8. Weighted recursive average filtering method
/* The coe array is a weighting coefficient table, which exists in the program storage area. */

# Define N 12

Char code coe [N] = {1, 2, 4, 5, 6, 7, 8, 9, 10, 11, 12 };
Char code sum_coe = 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11 + 12;

Char filter ()
{
Char count;
Char value_buf [N];
Int sum = 0;
For (count = 0, count <N; count ++)
{
Value_buf [count] = get_ad ();
Delay ();
}
For (count = 0, count <N; count ++)
Sum + = value_buf [count] * coe [count];
Return (char) (sum/sum_coe );
}

9. deshake Filtering Method

# Define N 12

Char filter ()
{
Char count = 0;
Char new_value;
New_value = get_ad ();
While (value! = New_value );
{
Count ++;
If (count> = N) return new_value;
Delay ();
New_value = get_ad ();
}
Return value;
}

10. amplitude limiting and jitter Filtering
/*
*/
For details, refer to subprograms 1 and 9.